Screen brightness control fails on Dell Studio 1558

[Andy Ross]

Attempts (on a current Lucid beta) to control the screen brightness on
my Dell Studio 1558 fail with the following errors reported in dmesg:

 [ 1162.236365] ACPI: Failed to switch the brightness
 [ 1162.379144] ACPI: Failed to switch the brightness
 [ 1162.538226] ACPI: Failed to switch the brightness
 [ 1162.667358] ACPI: Failed to switch the brightness
 [ 1162.784171] ACPI: Failed to switch the brightness

This is true both for the keyboard's brightness controls (Fn-F4,
Fn-F5) and for a gnome-brightness-applet on the panel.

Output of acpidump, dmesg and lspci is attached.

[Kevin Hester (kevinh)]

Also occurs (for me) on Lucid release candidate (same log messages)

[Jerone Young (jerone)]

Can someone post "lspci -vvnn" as well as /var/log/Xorg.0.log

[Andy Ross (andy-plausible)]

Logs as requested.

Also: following hints for similar bugs on other hardware, I tried adding
"acpi_backlight=vendor" to the kernel command line. No effect.

[Kevin Hester (kevinh)]

I tried acpi_backlight=video also and it was no good. Let me know if you want additional debug info (even to the point of letting you ssh into my machine if you want.

[Joe Luis (jlborrero)]

Yo tambián presento ese problema con los controles (fn-F4 y fn-F5) en mi laptop DELL Studio 1558.

[Kamal Mostafa (kamalmostafa)]

Note to testers: While investigating this bug, I discovered that "acpi_backlight=video" is actually non-functional (see LP: #573120). Even with that problem fixed acpi_backlight=video does not fix the brightness controls on the Dell Studio laptop. My investigation continues.

[Kamal Mostafa (kamalmostafa)]

I have developed a PRELIMINARY TEST FIX for this problem, which is caused by a dysfunctional ACPI _BCM backlight brightness control method in the Dell Studio 1558 firmware (and likely the other 155x models). The fix involves overriding the use of the _BCM method with the Intel GPU i915 driver's opregion backlight control method. The fix will therefore affect all i915-based systems that support the opregion method not just Dell Studio systems. This does fix the brightness keys on the Dell Studio 1558 and might also fix other i915 systems with backlight brightness control problems.

A binary kernel including this PRELIMINARY TEST FIX (as well as the source patch) is available here:
    http://kernel.ubuntu.com/~kamal/i915_brightness/
To install this kernel, download the two .deb files and install them using:
    sudo dpkg -i linux*kamal*.deb

Note that the test kernel also includes the fixes for LP: #553498 and LP: #573120 (even though the acpi_backlight= boot option is not required for the Dell Studio 155x with this kernel).

After rebooting, verify that "dmesg | grep backlight" yields the following line, signifying that the backlight will be controlled by the i915 driver:
    ACPI: ~kamal TEST acpi_set_backlight_register

Feedback to this bug report will be much appreciated, from Dell Studios or any other i915-based systems.

[Jerone Young (jerone)]

@Kamal
               have you submitted these to xorg & kernel lists? So others can look at them.

[Kamal Mostafa (kamalmostafa)]

@Jerone - This fix has not yet been submitted to the kernel lists, since I'm still working on polishing the patches -- I consider this to be a "PRELIMINARY TEST FIX" only, but I would like to get confirmation from the other bug subscribers that the method works without problems for them. The patches as they currently stand are available for inspection (at the same URL as the binary kernel). The patches will be sent upstream to linux-acpi and linux-kernel once they're ready.

[Kevin Hester (kevinh)]

Kamal,

Thank you - this fix is awesome! This fix combined with your other fixes for the new Dell Studios make them into one of the best linux laptops out there. If you are ever up in the peninsula send me an email - I owe you lunch!

[Andy Ross (andy-plausible)]

Tested and verified. It works great.

[Christopher Bankhead (christopher-bankhead)]

Kamal,

I have a Dell Studio 15 (1558) with the Intel i915.
After installing your fix, I no longer have issue with the brightness keys not working.

Thank you so much!

Chris

[quinosonic (joaquincruz)]

Got it running on a Studio 1558 (Intel i350) and it works fine. Thanks a lot Kamal, I was burnin' my eyes!!!

[Shlape (shlape)]

Just like to thank you Kamal, and to confirm the fix also works on my HP DV3 2105TU laptop.

[Andy Ross (andy-plausible)]

This apparently didn't make it into the 2.6.32-22-generic kernel that just got pushed. Are there verification steps needed to make sure it goes in for next time?

[Kamal Mostafa (kamalmostafa)]

Testers -- thanks very much for your valuable feedback. Note that this "i915 brightness" fix has NOT yet been applied to the Ubuntu development kernel, but it has now been submitted for comments to the relevant upstream development teams. For the time being, the fix is only available in the test kernels that I post to this bug, which I'll need to update after each intervening kernel release.

The latest build for Lucid is available here: http://kernel.ubuntu.com/~kamal/i915bri~3e/latest-lucid/ (source patch in the parent directory). To install this kernel, download the two .deb files and install them using:
    sudo dpkg -i linux*kamal*.deb

Note that the test kernel also includes the fixes for LP: #553498 and LP: #573120 (even though the acpi_backlight= boot option is not required for the Dell Studio 155x with this kernel).

After rebooting, verify that "dmesg | grep backlight" yields the following line, signifying that the backlight will be controlled by the i915 driver:
    acpi device:04: registered as backlight/i915

Feedback to this bug report will be much appreciated, from Intel GPU-based (i915 driver) systems.

[Kamal Mostafa (kamalmostafa)]

Minor corrections to my comment #20 about the ~kamal/i915bri~3e/latest-lucid test kernel:
 - There are three (not two) .deb files which need to be downloaded and dpkg installed.
 - This test kernel does not contain the (irrelevant) fix for 573120 acpi_backlight=.

[Shlape (shlape)]

The latest build still works for the HP DV3-2105TU laptop, and dmesg has the "backlight/i915" line.

Of less importance, I thought I'd mention that dmesg still has the old warning line:
[Firmware Bug]: ACPI: ACPI brightness control misses _BQC function

[entropia (yosoypia)]

Hi, I'm having this same brightness problem on my dell studio 1558 (intel i5) on which i have installed ubuntu 10.04 i386.
The patches above are built for amd64 architecture. Does anyone knows if there are any for i386 or if i can make the amd64 work in some way? Should I install the amd64 version?
Thank you all very much for your help!! :)

[entropia (yosoypia)]

Hi everybody!
I've reinstalled ubuntu 10.04 but this time the amd64 version, installed the above .deb and the brightness controls works perfectly: thank you kamal!!!!!!!! :)
I was wondering if its possible to fix the brigtness problem and the hang on resume after suspend together or if its better to wait to the next kernel release (since as they are different patches i'm not shure if installing the other one would leave the brightness fix not working).
Thank you!!

[znorris (znorris)]

Worked great for 64bit Ubuntu and Dell Studio 1569.

Thanks.

[Kamal Mostafa (kamalmostafa)]

Status update:

1. This patch is still pending review upstream. Thanks for your continued patience folks.

2. There was a recent official Lucid kernel update (2.6.32-23 #37), necessitating a rebuild of my "i915 brightness" test kernel. The latest build for Lucid (based on the current #38 development tree) is available here: http://kernel.ubuntu.com/~kamal/i915bri~3e/latest-lucid/ (source patch in the parent directory). To install this kernel, download the three .deb files and install them using:
    sudo dpkg -i linux*kamal*.deb

After rebooting, verify that "dmesg | grep backlight" yields the following line, signifying that the backlight will be controlled by the i915 driver:
    acpi device:04: registered as backlight/i915

[LeboyX (phreakizzle)]

This looks to be exact what I need, as a lack of brightness controls is killing me. Is there an i386 build for this yet, as I'm loathe to have to reinstall my OS.

[Kamal Mostafa (kamalmostafa)]

Folks, I will be distributing this "i915 brightness" test kernel in a PPA from now on (for both amd64 and i386). This should make it easier for those us that need the fix to regain it again after each official Ubuntu kernel release. Note that I've also included the popular SCI_EN sleep/resume fix from LP: #594837 in this PPA build as well:

    https://launchpad.net/~kamalmostafa/+archive/linux-kamal-i915bri

This is the same fix that we've had for awhile now (just re-applied to the latest Ubuntu Lucid kernel).

I will update the PPA as soon as I can after each Lucid kernel release until we can get a fix into the official kernel.

[LeboyX (phreakizzle)]

Just added the PPA, updated, and restarted. The patch works perfectly: my brightness controls work now. (I'm running Ubuntu 10.4, 32-bit on a Dell Studio 1558).

I didn't have any of the hang problems with sleep, but now I s'pose I never will.

Thanks! : D

[lohapuk (lohapuk)]

I have a hp envy 14 and this has fixed my brightness problems.

[Andreas Demmer (mail-andreas-demmer)]

Where can I see the patch source? I am running openSUSE and would love to have this fixed for my HP Envy 14 too...

[Andreas Demmer (mail-andreas-demmer)]

Ah, sorry, found the patches in your dir. Thx, I appreciate your work!

[lohapuk (lohapuk)]

Just wondering if resume works for you on the hp envy 14, using that patch it hangs once it has suspended and will not come back to life.

[Kamal Mostafa (kamalmostafa)]

Dell Studio 155x users take note: I have created a PPA specifically targeted to the Dell Studio 155x laptop. This PPA includes the experimental "i915 brightness" patch, as well as other useful experimental patches relevant to the Dell Studio 155x:

  https://launchpad.net/~kamalmostafa/+archive/linux-kamal-dellstudio

Users of other machines who want the "i915 brightness" patch should continue to use the non-Dell specific PPA:

  https://launchpad.net/~kamalmostafa/+archive/linux-kamal-i915bri

Thanks for your feedback and your patience, folks.

[lohapuk (lohapuk)]

any news on, if / when this patch will make it into the made kernel branch.

[chamilis (chamilis)]

Can the patches available in http://kernel.ubuntu.com/~kamal/i915bri~3e/ be applied to the kernel's source code from kernel.org?
I'm trying to get this problem fixed in Debian Squeeze.
Thanks

[santiago (santiagozky)]

is there any chance to have this in the official kernel soon? I'm having problems with the ppa and my eyes are hurting ;)

[J. Austin Rodriguez (jeanaustinr)]

Hi. I've tried downloading the .deb however, I still can't adjust the brightness of the screen. Mine is HP Pavilion dv3-2106tu. Is there anything needed for further troubleshooting?

[santiago (santiagozky)]

zszoet,It wasn't working for me. But the reason was that the gnome power manager wasn't running for some reason. I executed it and the brightness controls started working perfectly.
Perhaps that is your problem.

[Aviqc (davidanabel1)]

Will this announced patch work for a hp g62-227ca? Would it break my system if it didn't ? this would be my first attempt at installing such a patch.

[Aviqc (davidanabel1)]

oh, I forgot to add: dmesg yields nothing....

[Binoy Fernandez (binoyaf)]

Kamal, the fix (brightness) works perfectly for Dell 14R series laptops (N4010). Thanks a lot! I hope this soon makes it into the official kernel.

dmesg shows "acpi device:00: registered as backlight/i915"

[Mike Hicks (hick0088)]

I have encountered this problem on a Dell Inspiron 14R (N4010) when running Maverick (Ubuntu 10.10). I installed to 10.10 (still in alpha/beta at the moment) because the install media I had for Lucid 10.04 didn't support the onboard wired Ethernet device. Will any patches be submitted for the Maverick kernel, or will a Maverick kernel be available through the PPA site?

[J. Austin Rodriguez (jeanaustinr)]

@Santiago Garcia Pimentel R.G.
zszoet here. The power manager is running. But I still can't adjust the brightness.

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

@Kamal, this Kernel also repairs brightness controls AND suspend on my Lenovo Z360 Notebook.
How long does it take until it will be integrated into the main k.36ernel... Could you build a new (2.6.35 or 36) one for us maverick users?

[mike albo (mike-mikealbano)]

Also wondering when a patch to the stock kernel ( 2.6.32-24 ) will be available?

[[e-mail] (nadeepad)]

@Kamal, this fixed the brightness and suspend problems of my Inspiron 14R laptop. Thanks a lot.
After installing this kernel the headphone out was not working. I got it working by installing new alsa drivers. (Did it replaced alsa drivers?) I wish the kernel included new alsa drivers too!

[mike albo (mike-mikealbano)]

Can someone explain what to do from a fresh install? I added the ppa, but "apt-cache search kamal" returns nothing. apt-get update/upgrade does not show anything with kamal in it (or brightness i915). Fresh install has 2.6.32-24 kernel. I can't find anything in repository after adding ppa, relating to these fixes.

[flusheddata (flusheddata)]

The same problem here when using the ATI proprietary driver from the Lucid repo.
Anyway if install the ATI's last versión driver at their site the brightness indicator works ok. I've noticed that the ATI Catalyst Control Center apps (normal and root) disapear from the System>Administration menu sometimes when using this last one.
Waiting for a fix.

[Jerone Young (jerone)]

@flushedata
       Your problem is actually completely different then the one described in this bug.

[Hans (helpyoulinux)]

When will this patch add to main kernel ?.

Can someone please add this patch to main line ?

[cherep (acherep)]

hi Kamal,
I'm running Ubuntu 10.10 64bit kernel 2.6.35-22 and really hope that this bug will be corrected in the release (10th October 2010) because now it is not working from the main repository.
Thanks!!!

[Kamal Mostafa (kamalmostafa)]

Status update:

The upstream maintainers of the i915 driver have recently proposed a new backlight control mechanism[1], so my "i915bri" patch won't be applied to the mainline kernel or the official Ubuntu kernels. The good news is that the new proposed mechanism is a better approach and will likely fix the problem for more machines.

I am therefore focusing my efforts on backporting the new proposed mechanism to Ubuntu Maverick (2.6.35 kernel) and I expect to publish a Maverick PPA kernel (and the patches) here soon. This work is not likely to make it into the Maverick release in October. I have not yet evaluated whether or not it will be possible to backport this new mechanism to Ubuntu Lucid.

Some folks have asked whether I'm planning to port my "i915bri" patch to Maverick or other 2.6.35-based distros: Since the new mechanism will soon be available for Maverick, I do not intend to do so.

[1] http://lists.freedesktop.org/archives/intel-gfx/2010-September/008081.html

[Triyambakesh (3m.on.linux)]

Dear Kamal,
Thankyou for your response to my question. I look forward for the solution that u would be formulating/ designing regarding the screen brightness.....
Please let me know when you will load the program in the UBUNTU web page.... Thank you once again.....
Warm Regards ,TRIYAMBAKESH MOHANTY (M.Sc)
(MICROBIOLOGIST)
Microbiology & Molecular Biology of Mycobacteria & Tuberculosis
E-MAIL: <email address hidden>
Mobile No: [phone]
Stay connected
http://in.linkedin.com/pub/triyambakesh-mohanty/19/99a/953
http://www.brijj.com/triyambakesh-mohanty

--- On Thu, 9/23/10, Kamal Mostafa <email address hidden> wrote:

From: Kamal Mostafa <email address hidden>
Subject: [Bug 568611] Re: Screen brightness control fails on Dell Studio 1558
To: <email address hidden>
Date: Thursday, September 23, 2010, 1:14 AM

Status update:

The upstream maintainers of the i915 driver have recently proposed a new
backlight control mechanism[1], so my "i915bri" patch won't be applied
to the mainline kernel or the official Ubuntu kernels.  The good news is
that the new proposed mechanism is a better approach and will likely fix
the problem for more machines.

I am therefore focusing my efforts on backporting the new proposed
mechanism to Ubuntu Maverick (2.6.35 kernel) and I expect to publish a
Maverick PPA kernel (and the patches) here soon.  This work is not
likely to make it into the Maverick release in October.  I have not yet
evaluated whether or not it will be possible to backport this new
mechanism to Ubuntu Lucid.

Some folks have asked whether I'm planning to port my "i915bri" patch to
Maverick or other 2.6.35-based distros:  Since the new mechanism will
soon be available for Maverick, I do not intend to do so.

[1] http://lists.freedesktop.org/archives/intel-
gfx/2010-September/008081.html

--
Screen brightness control fails on Dell Studio 1558
https://bugs.launchpad.net/bugs/568611
You received this bug notification because you are a direct subscriber
of the bug.

Status in The Dell Project: Invalid
Status in “alsa-driver” package in Ubuntu: Invalid
Status in “linux” package in Ubuntu: In Progress

Bug description:
Attempts (on a current Lucid beta) to control the screen brightness on
my Dell Studio 1558 fail with the following errors reported in dmesg:

 [ 1162.236365] ACPI: Failed to switch the brightness
 [ 1162.379144] ACPI: Failed to switch the brightness
 [ 1162.538226] ACPI: Failed to switch the brightness
 [ 1162.667358] ACPI: Failed to switch the brightness
 [ 1162.784171] ACPI: Failed to switch the brightness

This is true both for the keyboard's brightness controls (Fn-F4,
Fn-F5) and for a gnome-brightness-applet on the panel.

Output of acpidump, dmesg and lspci is attached.

To unsubscribe from this bug, go to:
https://bugs.launchpad.net/dell/+bug/568611/+subscribe

[Kamal Mostafa (kamalmostafa)]

I have ported the proposed new backlight control mechanism[1] -- primarily the work of Matthew Garrett -- to Ubuntu Maverick (2.6.35 kernel). Many thanks to Matthew for his fine work!

An EXPERIMENTAL Maverick kernel PPA which includes the fix (plus some Dell-specific glue) is available. I have tested this on a Dell Studio 1558 only, but it may fix the brightness controls for other laptop brands and models also. See the IMPORTANT installation notes on the PPA page for more details:

Maverick PPA: https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

Feedback to this bug report will be appreciated.

Developers: The source patches are also available for inspection[2]. Be aware that Matthew's patches were slightly modified from their original form by me, for the 2.6.35 backport.

I do not intend to backport this work to Ubuntu Lucid at this time.

[1] http://lists.freedesktop.org/archives/intel-gfx/2010-September/008081.html
[2] http://kernel.ubuntu.com/git?p=kamal/ubuntu-maverick.git;a=shortlog;h=refs/heads/mjg-backlight

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

I'm on a Lenovo Ideapad Z360. My backlight devices are acpi_video0 and intel_backlight. I tried to disable the first device, but I can't find the module. This is my output:

ls -l /sys/class/backlight/acpi_video0/device
lrwxrwxrwx 1 root root 0 2010-09-24 21:10 /sys/class/backlight/acpi_video0/device -> ../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:01/device:02

What module do I have to disable? Maybe it will work afterwards, so you can autodisable it for future patch releases.

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

I figured I have to disable the module "video", but that just doesn't work. I added "blacklist video" to my blacklist.conf, but the module is loaded anyway.

[Kamal Mostafa (kamalmostafa)]

@Tito and other folks with /sys/class/backlight/acpi_video0:

To disable the "acpi_video0" backlight, boot with this kernel parameter[1]:

    acpi_backlight=vendor

However note that when I do so on my Lenovo Thinkpad, acpi_video0 disappears but then /sys/class/backlight/thinkpad_backlight appears in its place, so...

To disable "thinkpad_backlight", boot with this kernel parameter also:

    thinkpad_acpi.brightness_enable=0

Tito, please try booting with both of those parameters (together) and report your results.

[1] To add kernel boot parameters, append them to the "linux" or "kernel" boot line as demonstrated here:
https://help.ubuntu.com/community/Grub2#Editing%20Menus%20During%20Boot
https://help.ubuntu.com/community/BootOptions#Change%20Boot%20Options%20Temporarily%20For%20An%20Existing%20Installation

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

It works Kamal, thank you very much!!
I added both parameters, don't know if I need the second one, I will report you later.
Where will we find this patch, you said you backported it to maverick, will it appear in the 2.6.36 rc branch sometime?

[Kamal Mostafa (kamalmostafa)]

To clarify comment #55: This new backlight control mechanism is still considered "experimental". Matthew Garrett has proposed the core patches to the intel-gfx and linux-kernel groups, where they are still pending review. I will continue to report changes to the status of the patches here.

@Tito - Glad to hear that it works on your Lenovo IdeaPad Z360. Please do be sure to post whether or not the second parameter is actually needed for that model.

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

@Kamal: I definitely need both commands. When I use both, everything works. When I use only the first one, the following things happen: a) the fan goes crazy (this also happened with your old kernel after awaking from suspend, so a restart is needed to turn it off) b) the screen is very dark (in contrary to 100% as before) and the controls don't work, neither the fn keys nor the power managment brightness slider. c) however, only one backlight control (your new one) appears

Hope you can read something from that, especially why the fan goes high, I will try suspend tomorrow, but I guess this is some other matter...

[Adi Roiban (adiroiban)]

I have tested on a Dell Inspiron N3010 with Intel video and it works. It should also work on N4010 13n 14n or 15n with Intel video card as they have the same hardware.

I noticed that with this kernel the computer hangs for about 10 seconds before showing the splashscreen.

I used dell_laptop.backlight=0. Without this parameter the dell backlight module is loaded.

Thanks!

[Aditya Bhargava (rightaditya)]

I just upgraded to Maverick and then added your Maverick PPA. It only showed an update available for linux-libc-dev, which I installed, and as I suspected that had no effect. Is it just because the PPA isn't updated for the latest release (seeing as Maverick was only just released a few hours ago...)? I'm doing this on a Dell Studio 1558.

[Kamal Mostafa (kamalmostafa)]

I've corrected the problem with the PPA... It should now work properly when applied to Maverick release installs. (Thanks for reporting it Aditya!)

[Bruce Kearns (brkearns67)]

Kamal -- what is the status of the fix for the intel-gfx? Looks like the "second thought" comment did not lead to any more activity.

[Triyambakesh (3m.on.linux)]

Regarding screen brightness problem with Acer Aspire 5740 core i5 with Kubuntu/Ubuntu 10.10

Dear Kamal,
                  I just came to knew that U have corrected the issue towards screen brightness. Can U please guide me step by step how to install the package for correcting my screen brightness? I am new to Linux. Provide me the link for downloading your uploaded package. Details for installation. I am using Kubuntu + Ubuntu 10.10 Maverick on Acer Aspire 5740 core i5 Notebook Machine.
Please help me with this issue of screen brightness. Problem while using Fn + < & > keys shows the applet on the screen about decrease and increase of brightness whereas the actual brightness of the screen remains unchanged.

Thank you,

[Triyambakesh (3m.on.linux)]

PPA added- no difference was found

I added the PPA lines from your Technical Details of PPA into the APT of software source applied as per the instruction in the help menu of ubuntu. Not a single change was seen.. my screen brightness remains the same

[thugUA (lin-k)]

I've got Lenovo u350 laptop with intel 4500hd graphics and Ubuntu 10.10. After installing your kernel, brightness regulation works fine, but in a little while (10-20min) the system's interface starting to freeze: graphics draw very slow, when writing in console, letters appear not immediately. Some time later it returns to normal. When I return to native kernel, it doesn't happen. Do you have any idea how to fix this?

[Kamal Mostafa (kamalmostafa)]

I have updated the PPA with a new gnome-power-manager package which enables the new intel_backlight interface for brightness control regardless of the presence other backlight interfaces (so the various acpi_backlight=vendor and *backlight=disable kernel boot parameters should no longer be required for Gnome desktop users). Thanks again to Matthew Garrett for the original intel_backlight patches.

This updated version should enable the brightness controls for a wider range of Intel GPU based laptops.

  Maverick PPA: https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

Upstream status: the patches are still pending review upstream, and have not yet been applied.

[Sachin Garg (ascii79)]

Finally brightness works for laptop with this kernel .. But I need to append acpi_backlight=vendor

Model -- Gateway NV5927U

Thank you ...

[rivaldoleon (rivaldoleon)]

Kamal ... Please update the amd64 packages for maverick!!! ... I got this problem to .. Gateway ID49

[rivaldoleon (rivaldoleon)]

Uff!! Finally works!!! after kernel update.. Also i need to add acpi_backlight=vendor.

Model - Gateway ID49 ... Thks!!!

[J. Austin Rodriguez (jeanaustinr)]

Adding acpi_backlight=vendor in my grub.cfg does not fix it. After a restart, the screen brightness still does not respond. Full birghtness and it's hurting my eyes. Grrr....!

[J. Austin Rodriguez (jeanaustinr)]

It's now working! Just like what I thought, I missed something.
Thank you very much, Kamal!

[Luciano Dato (lucianodato)]

Thank You Very Much! Works on my Dell Studio 1558.

[Hendy Irawan (ceefour)]

UbuntuForums.org thread discussing this problem: http://art.ubuntuforums.org/showthread.php?t=1503569

I have a Lenovo IdeaPad Z360 and also having this problem.

[Hendy Irawan (ceefour)]

I have installed Kamal's fixed kernel from: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611/comments/55

Just installing the kernel doesn't make any effect.

During GRUB, after editing the 'linux...' line and appending 'acpi_backlight=vendor' the backlight works as expected.

THANKS Kamal! Right now my Lenovo Ideapad Z360 laptop is operating at 11.4 W (due to reduced backlight). It's usually 16 W (minimum) up to a max of around 25 W. This fix will definitely save me a lot when I'm away from the AC outlet.

Thanks a lot !!!!!!!!

Some minor things though:
* acpi_backlight=vendor shouldn't be required, however this workaround is MUCH better than not working at all....
* At first login my display was completely black. I thought the fix was not working (and I thought it made the computer unusable) until I pressed increased-brightness and it works. The thing is the brightness control works all the way until 0 (pitch dark). IMHO pitch dark shouldn't be allowed, because we already have the button work that (Fn+F2, which works very well), so the darkest brightness should be "a little bit brighter than pitch dark".
* PLEASE make it into official Ubuntu kernel on next update

[Hendy Irawan (ceefour)]

To always add acpi_backlight=vendor to your kernel, edit the /etc/default/grub file by running:

gksu gedit /etc/default/grub

and edit the following line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

into:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Save, and run:

sudo update-grub

[Jan Taborsky (jantaborsky)]

This works just perfect on my Acer 5810T (Timeline series), Masha'Allah!
I still have to disable acpi_video0 by acpi_backlight=vendor, even though acpi_video0 has disappeared from /sys/class/backlight. There's acer-wmi in its place now and I didn't try disabling that when I don't have to.
Immense thanks!

[Kamal Mostafa (kamalmostafa)]

Even though we know that the "linux-kamal-mjgbacklight" PPA kernel does work to enable brightness controls on many different models, lets leave the title of this bug as it was originally reported and not add any additional models to it. The reason being that if we keep adding additional models, we may never be able to manage to close the bug. I'm resetting the title accordingly.

People who test the PPA kernel and wish to report success should just file a comment to this bug listing their machines' make and model (which will help those searching for information about that model). Many thanks to all of you who have done that already. Your feedback is very useful.

People who test the PPA kernel but find that it does not fix their brightness controls should file a new separate bug report so that the details about that machine can be collected there.

[da_coynul (xtragb)]

This works great on Acer Aspire 5740! acpi_backlight=vendor kernel parameter is needed.

[Triyambakesh (3m.on.linux)]

At last the problem with LCD Screen brightness comes to an end.
I had the same problem with my Notebook Acer Aspire 5740, core i5 + Ubuntu 10.10 series
Now this got fixed permanently with adding the PPAs of Kamal Mostafa and Grub acpi_backlight=vendor.
All you need is to add PPA from Kamal's webpage https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight and then go for modifying the grub parameters with "acpi_backlight=vendor". To do so please follow the instructions as per the webpage, strictly. Kindly see the post #78 for acpi_backlight=vendor.

I am sure for those with 'intelbacklight' this would be useful in Maverick Series.

Thanx Kamal.

[Kamal Mostafa (kamalmostafa)]

I have posted a minor update to the kernel and gnome-power-manager packages in my PPA https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight . Users who have installed the PPA already don't need to take any special action -- your system's "Update Manager" will take care of upgrading the PPA automatically. This note is just for your information.

The updated kernel incorporates the latest changes from the official Ubuntu Maverick kernel, but no new changes to the experimental intel_backlight mechanism.

The updated gnome-power-manager incorporates these minor improvements to the brightness-up/down keys functionality for Gnome desktops:
  - the brightness "steps" now consistently fall on 5% increments
  - the brightness-down key now limits the lowest selectable brightness to 5% (very dim) instead of 0% (completely dark)

[stocchero (guga)]

Working on my Lenovo Ideapad U350.

lspci
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)

Needed both boot parameters,

acpi_backlight=vendor && thinkpad_acpi.brightness_enable=0

added to /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor thinkpad_acpi.brightness_enable=0"
GRUB_CMDLINE_LINUX="acpi_backlight=vendor thinkpad_acpi.brightness_enable=0"

after that, sudo update-grub.

The gnome applet for the panel is not working, but the keys work perfectly.

Thank you very much, Kamal.

[Mike Smullin (mike-smullindesign)]

worked great for my Dell Inspiron 17R. Thanks!

[Dan Miller (danfusion)]

Working fine on my HP Pavilion DV3 2155mx.

I needed to add the "acpi_backlight=vendor" boot parameter.

As reported in comment #87, the gnome brightness panel does not work but the function keys work perfectly.

Thanks, Kamal! You've fixed an issue that I've had since I first tried Ubuntu on this laptop (9.04).

[Jason Tiller (jason-sonos)]

Hi, Kamal. I wanted to let you know that your fix also worked for me with my Dell Studio 1458 with an i5 and integrated graphics for Kubuntu 10.04.

And good news for Kubuntu 10.10! It recognized all of my Fn keys out of the box!

And bad news for Kubuntu 10.10! After the first suspend/wake-up cycle, *none* of the keys are recognized. ::sigh:: Any ideas?

(Another bug has been opened for this:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/657338?comments=all
)

[Varun Kansal (varunksl)]

worked great for me on dell studio 15 with i5. Will it be a part of kernal 2.6.36? I really wish 2.6.36 will fix the backlight, wireless and hibernation, all three issues.

Thanks for your work!!

[Eduardo Manrique (manrique-e)]

It works great in gnome but i kde it's not working...

[Eduardo Manrique (manrique-e)]

By the way i have Ubuntu Maverick with kde 4.5, it's weird because in gnome works great, could be a kde problem?

[ombako (ombako)]

Hi Kamal

After updating the kernel (to 2.6.35-23-generic x86_64) minutes ago and restarting the system, I lost control over brightness again. It worked with no problems for over a month, but I'm needing sunglasses again! ;-)

I'm running Ubuntu 10.10 64 bits in a Lenovo z360.

Any ideas or tipps? By the way, thanks a lot for your help!

Omar

[José Luis Garza (jlgarza2)]

Hi Kamal

I have the same problem of Omar. Kernel updates and I lost the backlight control. I downloaded the packages

linux-image-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb
linux-headers-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb
linux-image-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb

I tried to install them but system says:

There is a newer version installed

¿Exists a way to apply the backlight patch to my current kernel version or downgrade to your kernel version?

Ubuntu 10.10 amd64
Gateway nv59 laptop intel corei5
Current kernel. 2.6.35-23.40 on x86/x86_64

Thanks in advance

Jose Luis

[José Luis Garza (jlgarza2)]

Hi Kamal

I just remove the packages linux-image and linux-headers from my system (version 2.6.35-23.40) then I installed your packages

linux-image-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb
linux-headers-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb
linux-image-2.6.35-23-generic_2.6.35-23.36+kamal~mjgbacklight1_amd64.deb

I recover the brightness control.

Now I will avoid the linux-image or linux-kernel upgrades if them are not from your kernel PPA.

I still wonder if there is a way I could patch newer kernel with your kernel enhacements for my laptop. I see .gz .dsc and .patch files in your PPA, but i don't know how to use them or if them are for general or only specific use for 2.6.35-23.36

Thanks

José Luis

[Kamal Mostafa (kamalmostafa)]

An update to the PPA is on the way folks -- build is in progress -- I'll announce when its available.

[AlexW (alex.wedensky)]

Kamal, are you planning to continue patching the Lucid kernels (2.6.32 series)?

[ombako (ombako)]

I just updated with the kernel from the PPA from Kamal and we are back to normal. Thanks a lot.
However, there is something else. One out of 3 or 4 times, when I turn the computer on I get this weird error.

1. When booting up, the kernel ring buffer is printed out on the screen. This usually does not happen. (When it does, I know I will have to restart ubuntu again).
2. The fan starts going crazy, it speeds up in several stages until maximum speed is reached (and remains like that).
3. I cannot adjust the brightness. I have to restart (sometimes twice) to get a normal session.

The funny thing is that it is not always like that. I had a look at dmesg and I got the following excerpt from it:

[ 1.935348] ------------[ cut here ]------------
[ 1.935410] kernel BUG at /build/buildd/linux-2.6.35/kernel/workqueue.c:312!
[ 1.935520] invalid opcode: 0000 [#1] SMP
[ 1.935637] last sysfs file: /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/bcdDevice
[ 1.935684] CPU 0
[ 1.935714] Modules linked in: ahci libahci atl1c
[ 1.935870]
[ 1.935900] Pid: 36, comm: kacpi_notify Not tainted 2.6.35-24-generic #40+kamal~mjgbacklight1-Ubuntu LL1 /Lenovo IdeaPad Z
[ 1.935963] RIP: 0010:[<ffffffff8107af19>] [<ffffffff8107af19>] queue_work_on+0x49/0x60
[ 1.936042] RSP: 0018:ffff880152ec5d50 EFLAGS: 00010286
[ 1.936081] RAX: ffff880150b62c90 RBX: ffff880150b62c00 RCX: 0000000000000000
[ 1.936126] RDX: ffff880150b62c88 RSI: ffff88015350b1c0 RDI: 0000000000000000
[ 1.936170] RBP: ffff880152ec5d50 R08: 0000000000000000 R09: 0000000000000000
[ 1.936214] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000080
[ 1.936258] R13: ffff88014f854000 R14: ffff880152564800 R15: ffff880152ec5fd8
[ 1.936303] FS: 0000000000000000(0000) GS:ffff880001e00000(0000) knlGS:0000000000000000
[ 1.936350] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1.936390] CR2: 00007f57c3a08560 CR3: 0000000001a2a000 CR4: 00000000000006f0
[ 1.936436] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1.936479] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1.936524] Process kacpi_notify (pid: 36, threadinfo ffff880152ec4000, task ffff880152eb16e0)
[ 1.936611] Stack:
[ 1.936660] ffff880152ec5d60 ffffffff8107af6f ffff880152ec5d70 ffffffff8107af98
[ 1.936798] <0> ffff880152ec5d80 ffffffff814402e2 ffff880152ec5db0 ffffffff81339490
[ 1.937002] <0> ffff880150794c80 ffff880151879798 ffffffff8130a8c5 ffff880001e19000
[ 1.937251] Call Trace:
[ 1.937305] [<ffffffff8107af6f>] queue_work+0x1f/0x30
[ 1.937364] [<ffffffff8107af98>] schedule_work+0x18/0x20
[ 1.937426] [<ffffffff814402e2>] power_supply_changed+0x12/0x20
[ 1.937488] [<ffffffff81339490>] acpi_battery_notify+0x9d/0xa6
[ 1.937551] [<ffffffff8130a8c5>] ? acpi_os_execute_deferred+0x0/0x36
[ 1.937614] [<ffffffff8130da85>] acpi_device_notify+0x19/0x1b
[ 1.937676] [<ffffffff8131b955>] acpi_ev_notify_dispatch+0x67/0x7e
[ 1.937740] [<ffffffff8130a8ee>] acpi_os_execute_deferred+0x29/0x36
[ 1.937802] [<ffffffff8107a775>] run_workqueue+0xc5/0x1a0
[ 1.937864] [<ffffffff8...

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

Great, so I am not the only one with the crazy fan speed problem. But when it happens, everything else is working, just the noise...

[Tito Torrisi (tito-torrisi-deactivatedaccount)]

I'd like to add: The crazy fan problem also happens randomly to me, I don't know when or why, it's like a crazy surprise :P

@Kamal, would you mind throwing us a 2.6.36 Kernel?!

Thanks

[Kamal Mostafa (kamalmostafa)]

I have posted an updated Maverick kernel (2.6.35-24.40+kamal~mjgbacklight1 for Ubuntu 10.10) in my PPA https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight . Users who have installed the PPA already don't need to take any special action -- your system's "Update Manager" will take care of upgrading the PPA automatically. This note is just for your information.

Official Ubuntu kernel status: This backlight brightness patch is still not yet included in official Ubuntu kernels because it is still being debated upstream on the intel-gfx mailing list. We'll move towards getting this into the officlal Ubuntu kernels once it finally lands upstream.

@Alexw - I am not planning to do any further work on the Lucid 2.6.32 kernel for this issue.

@Tito - I do plan to supply a patched Natty 2.6.36 kernel for this issue in the near future. I will use the same PPA and will announce here when that's available.

People with the "crazy fan speed" problem - Is there reason to think that the fan problem relates to the backlight brightness patch? If not, that problem should be reported separately.

[cherep (acherep)]

@Tito, @ombako
I have exactly the same issue with "crazy fan speed" on my Lenovo z360. But if I remember it right, it started going crazy since I had switched from 10.04 to 10.10 (this patch wasn't installed). I guess it is not related to the brightness control patch. Correct me if I'm wrong!!!

[brut (brut-fruit)]

@Kamal
thanks i have a Dell14R N4010 and your fix worked for me

[rvgsd (rvgsd-id1)]

Dear Kamal,
I had installed your fix about a month back and it was excellently until a couple of days back when I did a "sudo apt-get update && sudo apt-get upgrade". I don't remember seeing any kernel related packages in the update.
I am using the Dell Studio 1558 laptop, I still use the acpi_backlight=vendor as a start up parameter, but now it doesn't work.
I wonder if anyone else had this issue.
Thanks!

[J. Austin Rodriguez (jeanaustinr)]

rvgsd, I had the same issue too after updating but had to resort to reinstalling power management via Kamal's PPA and the Linux packages. See what kernel version you have by typing uname -a in a Terminal.

[rvgsd (rvgsd-id1)]

Thanks for the info Jean!
My kernel is: 2.6.35-23-generic-pae #40-Ubuntu SMP Wed Nov 17 22:32:51 UTC 2010 i686 GNU/Linux
How do I reinstall the power management module?

[rvgsd (rvgsd-id1)]

Sorry! I see what you mean. I wonder how it reverted back to the other kernel image. Reinstalling now.

[J. Austin Rodriguez (jeanaustinr)]

With Kamal's PPA, the kernel version should be 2.6.35-24 (with #40+kamal~mjgbacklight1-Ubuntu). But I think this has been fixed by the latest kernel (official) update. Can someone confirm?

And should this thread be given a more appropriate title?

[Bogdan (bogdan-t)]

Thanks to Kamal Mostafa, my friend's Acer TravelMate 5335 now does change brightness, however not quite as expected.

Here's the log of my actions:
1. Added PPA, installed new kernel and power-manager.
2. Reboot: got a black (not blank) screen, Fn+arrows did nothing, but I was able to login blindly (judging from the system login sound).
3. Added acpi_backlight=vendor, reboot: black screen again, but this time after login I was able to change screen brightness. (I haven't tested, but it could be that in #2 above Fn+arrows also did work after login even without acpi_backlight - may test that later.)

Now to the problem. On this Acer Fn+left should decrease brightness and Fn+right should increase.
Here's what really happens:
1. When pressing Fn+left, the on-screen brightness indicator shows 'decrease' (gauge shrinks to the left), but actual brightness increases.
2. Fn+left doesn't go all the way to the left - there's a small bit of gauge left (presumably to avoid completely black screen).
3. Fn+right causes brightness OSD to move right (as if increasing), but actual brightness goes down.
4. The last step of Fn+right (brightness gauge all the way to the right) blanks the screen.

Could someone please advise on how to fix this "inverted" behavior? It would be OK, if not the automatic "dimming" of the screen: it actually increases brightness when inactive, and if not the black login screen.

Thanks in advance for any hints/links/help.

[Bogdan (bogdan-t)]

Forgot to mention:
1) I didn't have 'ACPI: Failed to switch the brightness' in dmesg - it just didn't work silently.
2) Acer TravelMate 5335 comes with 'Intel GMA 4500MHD'

[Kamal Mostafa (kamalmostafa)]

@JeanAustinR - In reference to comment #110: No, the brightness issues have not yet been fixed in the official Ubuntu kernels.

@Bogdan - The inverted behavior is very curious indeed. To help further diagnose the cause, please run these commands in a terminal window:
  $ cd /sys/class/backlight/intel_backlight
  $ cat max_brightness
Please report the "max brightness" value that gets printed out here. For example, mine yields the value 4882.

Now try changing the brightness manually to various fractions of your max value, for example with my max of 4882, I do:
  $ echo 1000 | sudo tee brightness # this should be very dark
  $ echo 2400 | sudo tee brightness # should be about half brightness
  $ echo 4882 | sudo tee brightness # should be maximum brightness
(don't set the brightness to 0, or else your screen will likely go totally dark).

When you change the brightness manually this way, does the actual screen brightness behave as expected or is the behavior "inverted"?

[Bogdan (bogdan-t)]

Dear Kamal, thank you for continuous support and help with this issue.

$ cat max_brightness
368475

$ echo 368475 | sudo tee brightness
368475

The above makes the screen totally black.

$ echo 0 | sudo tee brightness
0

Zero sets the screen to maximal brightness.

$ echo 184000 | sudo tee brightness
184000

This yields about half-bright screen.

Other values I've tried (10000, 350000) also support the pattern of "inverted brightness numbers".

lshw gives this in the first "display" entry:
*-display:0
             description: VGA compatible controller
             product: Mobile 4 Series Chipset Integrated Graphics Controller
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             version: 09
             width: 64 bits
             clock: 33MHz
             capabilities: msi pm vga_controller bus_master cap_list rom
             configuration: driver=i915 latency=0
             resources: irq:44 memory:90000000-903fffff memory:80000000-8fffffff ioport:4110(size=8)

Please let me know if there's anything else I can do to help.

[Adi Roiban (adiroiban)]

In case you also have enabled the 'proposed' repository, the package from the wonderful Kamal PPA will be eclipsed by the 2.6.35-24.42 version uploaded a couple of days ago (07.12.2010) in proposed.
Otherwise Kamalas PPA works like champ.
Cheers,

[cherep (acherep)]

I have the same. Proposed updates turned brightness control off!!!

[Kamal Mostafa (kamalmostafa)]

@Adi - thanks for pointing that out... Users who have enabled updates from the 'maverick-proposed' repository, take note: As a general rule, updates to my PPA will follow updates to maverick-proposed by a few days.

I have posted an updated Maverick kernel (2.6.35-24.42+kamal~mjgbacklight1 for Ubuntu 10.10) in my PPA https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight . Users who have installed the PPA already don't need to take any special action -- your system's "Update Manager" will take care of upgrading the PPA automatically.

Upstream status: On hold; Patches to be resubmitted in the 2.6.38 time frame. I will continue to support the PPA for Ubuntu Maverick (and soon Natty) until the patches land. Thanks for your patience in the meantime, folks.

[Kamal Mostafa (kamalmostafa)]

My backlight PPA at https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight has been updated with a revised version of the experimental backlight control patches. The revised patch set may now also enable backlight brightness controls for Radeon graphics processors in addition to Intel graphics processors (see the PPA page for details).

The PPA now supports Ubuntu Maverick (10.10) and Ubuntu Natty (11.04 alpha).

Users who experience any change in functionality from the previous PPA versions should contact me or post here.

[Eduardo Manrique (manrique-e)]

I just install the new version and for me stop working at all, i'm using maverick

[J. Shaw (eri-dslextreme)]

Updated to new version today and it seems that the function keys have been disabled, so I have no brightness controls that are easily available. I can pull it up with the applet, and it still works otherwise. I am on a Gateway NV59 notebook. I do wonder, also, why the brightness levels never start at the correct level on this machine: when I adjust after rebooting, the levels reset themselves to the previous shutdown levels (i.e. reasonably dark), but when the machine is on the Ubuntu splash page up until I've logged in and can control them, it's always at maximum brightness.

I say this, at any rate: thank you very, very much for making this notebook, and others, usable again! I appreciate that you have done this a whole lot.

[Eduardo Manrique (manrique-e)]

Same to me, the brightness control are not avalible, but directly in gnome power-manager i can move the brightness, i lost the Fn key in both gnome and kde...

And of course thaks for you're help really thanks...

[Kamal Mostafa (kamalmostafa)]

@Eduardo and @J. Shaw -

Sorry for the regression...

1. Does booting with the kernel parameter "acpi_backlight=vendor" fix it? (see the PPA instructions page)

2. Please post or email me the output from: $ ls /sys/class/backlight

Thanks, -Kamal

[J. Shaw (eri-dslextreme)]

I have already put acpi_backlight=vendor, as I've got intel_backlight, and the function keys are still not happy after making sure of this and rebooting for the sake of redundancy.

[ombako (ombako)]

Same problem here. After updating to the latest version, I cannot adjust the brightness with the function keys. I can use however the Power Manager Brightness Applet, or overwrite the value in /sys/class/backlight/intel_backlight/backlight and thus I can control the brightness.

I also checked the kernel parameters and they are still the same as before.

The output from
$ ls /sys/class/backlight/
is:
intel_backlight

Thanks for all the help!

[ombako (ombako)]

Hi Kamal,

I've just noticed a second side effect of the last update of the kernel. When I suspend the machine (whether by choosing suspend in the power menu, or by closing the computer's lid) Ubuntu freezes. I have to press and hold down the power button in order to turn the machine off.

I am attaching an excerpt of dmesg, which perhaps might have some hints to the problem, but I am not sure.

Greetings,

Omar

[ombako (ombako)]

Hi everyone,

It's me again. This issue with not being able to suspend is driving me crazy. It's really annoying.
Does any one know how to go back to the previous Kamal-kernel version? I tried forcing a version in synaptic, but no luck. I also tried choosing a previous kernel at boot time, but there I cannot adjust brightness at all.

Anyone? Thanks in advance,

Omar

[Praveen Bhadrapur (praveenkumar-bhadrapur)]

Hi Kamal,

My problem: Brightness keys not reducing the brightness.

I have tried using the fix provided by you through the patches. I am not able to see it working.

My configuration : Dell Studio 1558 + Ubuntu 10.04.1 LTS \n \l

I see the following messages , when I use my brightness keys , even after applying the fixes suggested:

[ 143.057696] ACPI: Failed to switch the brightness
[ 143.331337] ACPI: Failed to switch the brightness
[ 143.759626] ACPI: Failed to switch the brightness
[ 144.286108] ACPI: Failed to switch the brightness
[ 150.313202] ACPI: Failed to switch the brightness
[ 150.575592] ACPI: Failed to switch the brightness
[ 150.764477] ACPI: Failed to switch the brightness
[ 150.949346] ACPI: Failed to switch the brightness
[ 151.117692] ACPI: Failed to switch the brightness
[ 151.267894] ACPI: Failed to switch the brightness
[ 152.695798] ACPI: Failed to switch the brightness
[ 152.980604] ACPI: Failed to switch the brightness
[ 153.252080] ACPI: Failed to switch the brightness
[ 153.643935] ACPI: Failed to switch the brightness
[ 162.714570] ACPI: Failed to switch the brightness
[ 162.893770] ACPI: Failed to switch the brightness
[ 163.082020] ACPI: Failed to switch the brightness
[ 163.258148] ACPI: Failed to switch the brightness
[ 163.412940] ACPI: Failed to switch the brightness
[ 163.598386] ACPI: Failed to switch the brightness
[ 163.771619] ACPI: Failed to switch the brightness
[ 163.948742] ACPI: Failed to switch the brightness
[ 188.533360] ACPI: Failed to switch the brightness

Please let me know, what needs to be done, if I have missed anything here.

I appreciate you help!

Thank you,
Praveen.

[Kamal Mostafa (kamalmostafa)]

I have posted an updated Maverick kernel (version 2.6.35-24.42+kamal2~mjgbacklight1) to my backlight PPA at https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight to address the recent regression in functionality reported by some users.

The updated kernel is currently queued up to build and should appear later today.

[ombako (ombako)]

Hi Kamal,

Thanks for the new kernel. It's working like a charm!

I still have a question though. With the functions key I am able to set the brightness to a minimum of 246.
But with $ echo xxx | sudo tee backlight #(the command you recommended in #113) I am able to go all the way to 0.
Is there to way to adjust the range of the value of the brightness controlled by the functions key to be able to go that far too?
That will be great if I could do that!

Thanks again for the great work!

Omar

[Kamal Mostafa (kamalmostafa)]

@Ombako- Thanks for the feedback.

Regarding the minimum selectable backlight brightness value... One of the features of the patched gnome-power-manager in the PPA is that it chooses to limit the minimum brightness value to 5% of the maximum value for intel_backlight; it specifically doesn't set the brightness value all the way down to 0. The reason is that setting brightness to 0 for intel_backlight results in the backlight being switched completely off (on my Intel GPU systems at least), but the "standard" behavior for the brightness control keys is that the lowest selectable value should be very dim but not completely off.

Ombako, when you "echo 0 | sudo tee brightness" does your backlight switch off completely like mine does? If not (i.e. if your 0 value actually results in very dim but not off) then I'll need to rethink my assumptions about the minimum value situation.

[jorgejhms (jorgejhms)]

Is there an option for Lucid users??

[ombako (ombako)]

@Kamal

I just had a look again. A value of 0 renders a completely black screen. With a value of 1 I can start seeing shapes.
Most of the time I work with a brightness between 100 and 200. Since the functions key won't go that far, I use the prompt line. I thought that a solution to my question would be something like editing a text configuration file. That's why I asked. But it seems it is a bit more complicated than that.
Thanks a lot anyways.

[ombako (ombako)]

Hi Kamal,

Me again. This is now weird and somehow embarrassing. This morning I tried again to set the brightness to 0, and this time I noticed that the screen is not completely dark. I don't know if yesterday evening I was a bit blind or what.
Anyhow, definitely with a value of 0 the screen is not off.
Greetings,

[Bogdan (bogdan-t)]

On my GMA4500 setting brightness to minimum turns off backlight completely, but with external lighting something can still be seen on a screen (because the image is still there, even though there is no backlight). It looks similar to what the reflective cell phone's screen looks like when it goes dark - you can still see symbols on the screen, but you wouldn't be able to see them if you were in a dark environment.

So I believe power manager should not allow setting brightness to absolute minimum.

[nmvictor (nmvictor)]

I installed the kernel but on booting,I was greeted with a black screen after selecting kamals kernel from the boot menu! Thank God I hadn't removed my previous kernel so i rebooted back into the 2.6.35.23 kernel and appended the options "acpi_osi=Linux acpi_backlight=vendor" at the GRUB_CMDLINE_LINUX_DEFAULT key in the /etc/default/grub file. I rebooted into kamals kernel but the screen was still black I toyed with Fn+LEFT and Fn+RIGHT keys which adjust screen brightness on my Acer Aspire 5734z, it worked, the screen slowly gained brightness but I noticed something weired which judging from this page, it was expected. The adjustments were inverse, Bright meant Dim and the other way round. I had also checked "Dim when Idle" option in my System>Preference>Power Management and so something else, when Idle, the screen brightens! All this is weired but many thanks to Kamal Mostafa, at least we have even the slightest control over screen brightness, my eyes are photophobic so you can imagine what this bug-fix means to me. I read somewhere in ubuntu forums about trying to remove gnome power manager at start up then starting it up manually at the command line as a workaround for the black screen at start up, well that seems like a huge sacrifice so I haven't tried it but lest I'm forced to, I'll let you guys know of my findings.

[Matías Albanesi (matias-debian)]

Hi Kamal, today I upgraded to Ubuntu Maverick 10.10 from 10.04 and then upgraded from your previous "i915bri" kernel to this one. I can report this patch works, but not so well as the former i915bri for Lucid.

My machine is a Toshiba T135-S1310, so it contains an Intel GMA 4500M chip. I had to add "acpi_backlight=vendor" to the kernel parameters.
While booting and before entering Gnome, brightness keys don't work. Just after booting, backlight goes to zero automatically so the screen is absolutely black. Once one brightness key is pressed image can be seen (and then the brightness indicator never reaches zero afterwards). And as you already explained, this patch is not helpful for KDE users.

ls -l /sys/class/backlight:

lrwxrwxrwx 1 root root 0 2011-01-01 21:43 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

Can we expect these changes to be applied to the mainstream 10.10 kernel? Or to 10.04 LTS?

Thank you, and thanks for all the work on the i915 driver.

[Sohail Mirza (mirzmaster)]

Does this bug describe the same issue as bug #562005? The other bug seems to describe the issue as affecting a broader class of users, those with a particular family of Nvidia mobile chipsets, whereas this bug talk about a specific family of Dell laptops.

I experience this very issue on my Lenovo T510 with Nvidia NVS 3100M, which is what led me to this bug initially, and then 568005.

[Kamal Mostafa (kamalmostafa)]

General info (nothing new)...

My backlight PPA at https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight provides an experimental brightness control fix for Ubuntu Maverick (10.10) and Natty (11.04) systems with Intel i915 graphics processors (and possibly Radeon (untested)). The patches, primarily the work of Matthew Garrett, are still pending review upstream. Inclusion of these patches in the official Ubuntu kernels will likely occur only after the patches settle in the upstream kernel trees.

@everyone: Thanks very much for all the feedback and test results folks.

@jorgejhms, @Matias: There is no actively maintained solution for Ubuntu Lucid (10.04) -- my old "linux-kamal-i915bri" PPA for Lucid is stale and will no longer be maintained. I think its unlikely that any further work on this issue will occur for Lucid.

@Sohail: No, this bug is not the same issue as the Nvidia bug you referenced (but thanks for noting the similar problem).

[chreko (chreko)]

I am not sure if this bug is affecting me, and if I am right to post my comment here. I am using Ubuntu 10.10 (AMD64) on a HP ENVY 14 with an Intel i5 CPU (and integrated GPU).

The fn keys (fn+f2 and f3) for controlling the brightness do work. However, I noticed the following:

1.) Ubuntu did start with dark screen (minimum brightness set to 0) as described here (http://ubuntuforums.org/showthread.php?t=1593079).
Adding "echo 2 > /sys/class/backlight/acpi_video0/brightness" to /etc/init.d/rc.local as sugessted did help.

2.) Settings in gnome-power-manager related to the backlight had no real effects, except on notify-osd. For example, although brightness_dim_battery (LCD dimming amount when on battery) was set to 50, unplugging the notebook had no effects on the brightness, but notify-osd appeared to be reduced by a half.

3.) the notify-osd was completly out of sync; while it could only be increased and decreased in five steps, the brightness itself could be changed in ten steps. A similar bug was reported here (https://bugs.launchpad.net/ubuntu/+source/notify-osd/+bug/351326). Adding "acpi_backlight=vendor" as suggested as a solution did deactivate the fn keys (fn+f2 and f3) completely and /sys/class/backlight became empty. However, ubuntu did start with full-bright screen.

I am wondering now if the backlight PPA could be a solution to my problem?

[cherep (acherep)]

@Kamal

after the last kernel update, I can't control my brightness via functional keys :)

uname -v -r
2.6.35-25-generic #44-Ubuntu SMP Fri Jan 21 17:40:44 UTC 2011

What should I do to get it working back?
Thanks!!!

[Luciano Dato (lucianodato)]

Same problem here, same kernel.

2011/1/27 cherep <email address hidden>

> @Kamal
>
> after the last kernel update, I can't control my brightness via
> functional keys :)
>
> uname -v -r
> 2.6.35-25-generic #44-Ubuntu SMP Fri Jan 21 17:40:44 UTC 2011
>
> What should I do to get it working back?
> Thanks!!!
>
> --
> You received this bug notification because you are a direct subscriber
> of the bug.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> Status in NULL Project:
> Invalid
> Status in “alsa-driver” package in Ubuntu:
> Invalid
> Status in “linux” package in Ubuntu:
> In Progress
>
> Bug description:
> Attempts (on a current Lucid beta) to control the screen brightness on
> my Dell Studio 1558 fail with the following errors reported in dmesg:
>
> [ 1162.236365] ACPI: Failed to switch the brightness
> [ 1162.379144] ACPI: Failed to switch the brightness
> [ 1162.538226] ACPI: Failed to switch the brightness
> [ 1162.667358] ACPI: Failed to switch the brightness
> [ 1162.784171] ACPI: Failed to switch the brightness
>
> This is true both for the keyboard's brightness controls (Fn-F4,
> Fn-F5) and for a gnome-brightness-applet on the panel.
>
> Output of acpidump, dmesg and lspci is attached.
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscribe
>

--
Luciano Dato

[Kamal Mostafa (kamalmostafa)]

@cherep, @Luciano - Your trouble is because you have the maverick-proposed repository enabled, so you're running the new kernel published to proposed yesterday (my kernels show "kamal" in the uname output). My PPA kernels will ordinarily lag behind maverick-proposed by a day or two. You can disable/enable maverick-proposed with the checkbox at Update Manager->Settings->Updates->"Pre-release updates". ... Or ... You can just stand by: I have just uploaded a new kernel to the PPA which will supersede the one currently in maverick-proposed. The PPA kernel is building now so should be available later today.

[cherep (acherep)]

@Kamal
after updating it works as before! Thanks for your help!

[Kamal Mostafa (kamalmostafa)]

For the record, the PPA kernel that I released earlier today contains an older "uname" version string than it should. No special action is needed -- this note is just to prevent careful observers from being confused by the odd version string. While this is just a cosmetic error, I have uploaded a replacement kernel with a corrected version string (so you can expect another update forthcoming some time later today).

@cherep - Thanks for your report.

[captain toro (commander1oldsmobile)]

Thank you, thank you, thank you for the brightness fix kernels. I have tried the vmlinuz-2.6.35-25-generic and the vmlinuz-2.6.37-12-generic and the /sys/class/backlight/intel_backlight/brightness control works nicely for both.
I went slightly blind looking at the Ultrabright 1080p screen in my Dell 1558 i3 with integrated intel graphics. Some aspirin helped my blinding migraine until installing your kernels and getting the screen dimmed before going totally blind. I am using Debian sid so really appreciate the new kernels. The deb files installed with no difficulty after installing the wireless-crda dependency. And my eyeballs thank you for saving their lives.

[chamilis (chamilis)]

Dear Kamal, I'm running Debian Squeeze with a compiled kernel patched with the .diffs from the link in message number 11. The patches worked fined with debianized sources installed from repositories (2.6.32).
Now I'm trying to patch kernel 2.6.37 without succes. I'm getting the debianized sources from experimental repositories but the patches don't apply.
Did you make a modification to the patches to make them suitable for the latest kernel.
Thanks

[Aditya (adityapatadia)]

I am experiencing same problem on my Sony VAIO VGN-NS328j laptop. When I press Fn+F5 or Fn+F6 the brightness doesn't get changed. I upgraded from lucid today. The brightness control was working fine in Lucid. Please contact me if you need for info or log files.

[Kamal Mostafa (kamalmostafa)]

@chamilis and others trying building their own kernels-

Yes, substantial modifications were needed to port these patches to the 2.6.35 and 2.6.37 Ubuntu kernels. My source trees are available via the links in the "PATCHES / GIT BRANCHES" section of the PPA web page:

https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

[Kamal Mostafa (kamalmostafa)]

@Aditya-

I believe the problem with Sony VAIO brightness keys that you noted in comment #147 is being tracked as bug 658198, the fix for which was applied to Ubuntu Maverick (10.10) just yesterday. I expect that you'll see it fixed by the next Maverick kernel update.

[chamilis (chamilis)]

Thanks Kamal!

[Peter-jezdec (peter-jezdec)]

I applied ppa:kamalmostafa/linux-kamal-mjgbacklight to my Dell Inspiron N7010, and it fixed my backlight problem. I didn't have to add any boot parameters. Thanks!

[Peter-jezdec (peter-jezdec)]

I forgot to mention that intel_backlight and dell_backlight appear in /sys/class/backlight

[Frank M Dexter (fmdexter)]

The patch / fix ppa:kamalmostafa/linux-kamal-mjgbacklight worked for me! I have a Gateway NV5913u notebook with Ubuntu 10.10 amd64. The Fn keys and the power management slider both work, finally I can see without wearing sunglasses. I had to apply the acpi_backlight=vendor line to disable the old acpi_video0 line. I hope this helps other people, I see that there are a lot of users on the ubuntu forums that could benefit from this info. Thank you very much!

[philipballew (philipballew)]

on my dell studio i558 the ppa: ppa:kamalmostafa/linux-kamal-mjgbacklight and now the laptop starts with contrast all the way down. has anyone else found this error and is there a workaround?

[Kamal Mostafa (kamalmostafa)]

On Wed, 2011-02-09 at 02:52 +0000, philipballew wrote:
> on my dell studio i558 the ppa: ppa:kamalmostafa/linux-kamal-
> mjgbacklight and now the laptop starts with contrast all the way down.
> has anyone else found this error and is there a workaround?
>

Hi philipballew-

I'm surprised that you're having this trouble with my PPA on your Studio
1558, since that is the exact machine that I use to test the PPA and I
don't experience it. I have a few questions:

Are you using the default Gnome desktop or KDE (or something else?)

When it starts "all the way down", is is completely black or just very
dim?

Does the graphical login screen appear with darkened brightness, or does
the problem only occur when you log in?

Do the brightness control hotkeys work normally after that, or not?

Finally, please send me the output from running these commands in a
terminal window:

$ uname -a

$ ls /sys/class/backlight

$ cat /sys/class/backlight/intel_backlight/max_brightness

Finally, please run this command in a terminal window, then send me the
resulting file /tmp/lspci.output:

$ sudo lspci -vvnn > /tmp/lspci.output

Thanks,

 -Kamal

[philipballew (philipballew)]

i will do that, though first to avoid looking like an idiot, im going to see if this ppa reseted my brightness to zero or if the settings were already at zero and because of the brightness problem unaffected until the ppa install.

[Shlape (shlape)]

Hi Kamal,

I've tried the latest kernel release and it works great except for a minor issue.

I lock the PC's screen while I'm away from it, and have it set to 'blank' the screen (no screensaver animation).
I usually have the screen set to between 1/4 and 1/2 max brightness. After a while of being away from the PC, the screen powers off. When I go to log in again the brightness has changed to 100%. After logging back in, if I go to adjust it back, it jumps down to the previous setting of between 1/4 and 1/2 max brightness.

Sounds like a bug?

[Matthias Schmiddunser (mschmiddunser)]

Hi,

I tried the patch today on a Leonvo Z360 running on xubuntu 10.10.

After installing the fix and adding the line acpi_backlight=verdor, I am able to adjust brigthness with the brightness control in the panel. However, the hotkeys don't work (minor issue, I can live with that), but as soon I reduced the brightness once, I can never get back to the original (maximum) brightness, it will always stay dimmer.

uname -a
Linux Karl 2.6.35-25-generic #44+kamal2~mjgbacklight1-Ubuntu SMP Thu Jan 27 23:45:18 UTC 2011 x86_64 GNU/Linux

cat /sys/class/backlight/intel_backlight/max_brightness
4882

Any ideas on how to fix that?

Thank you,
Matthias

[cherep (acherep)]

@Matthias
probably you should read the patch description carefully. I've changed this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor thinkpad_acpi.brightness_enable=0"
in /etc/default/grub.

After update it works on my Lenovo Z360.

[Matthias Schmiddunser (mschmiddunser)]

Yeah, I read it and tried it, but it produces no effect whatsoever comprared to only booting with the "acpi_backlight=vendor" line - I have exactly the same problem again.

[J. Austin Rodriguez (jeanaustinr)]

Has anyone tried running Virtualbox with this temporary package? Since applying the PPA, I cannot run a virtual machine properly, only if I reboot and select another kernel version.

[Hunk (enrique-garciasimon)]

Virtualbox (4.0.4 r70112) works fine for me (Acer Aspire 5810T)
2.6.35-27-generic #47+kamal~mjgbacklight1-Ubuntu SMP Tue Feb 15 18:33:12 UTC
2011 x86_64 GNU/Linux

2011/2/19 JeanAustinR <email address hidden>

> Has anyone tried running Virtualbox with this temporary package? Since
> applying the PPA, I cannot run a virtual machine properly, only if I
> reboot and select another kernel version.
>
> --
> You received this bug notification because you are a direct subscriber
> of the bug.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> Status in NULL Project:
> Invalid
> Status in “alsa-driver” package in Ubuntu:
> Invalid
> Status in “linux” package in Ubuntu:
> In Progress
>
> Bug description:
> Attempts (on a current Lucid beta) to control the screen brightness on
> my Dell Studio 1558 fail with the following errors reported in dmesg:
>
> [ 1162.236365] ACPI: Failed to switch the brightness
> [ 1162.379144] ACPI: Failed to switch the brightness
> [ 1162.538226] ACPI: Failed to switch the brightness
> [ 1162.667358] ACPI: Failed to switch the brightness
> [ 1162.784171] ACPI: Failed to switch the brightness
>
> This is true both for the keyboard's brightness controls (Fn-F4,
> Fn-F5) and for a gnome-brightness-applet on the panel.
>
> Output of acpidump, dmesg and lspci is attached.
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscribe
>

[J. Austin Rodriguez (jeanaustinr)]

Alright, I got it. If I use the generic-pae kernel, Virtualbox won't work. So I set my grub to automatically boot to the -generic (without pae) kernel -- the power management option works and so does Virtualbox. Finally! {I'm happy at least for now.}

[chamilis (chamilis)]

Kamal:
I wasn't able to find the kernel patches in your sources trees. Should I get source files from the tree and replace them in my Debian sources?

[Kamal Mostafa (kamalmostafa)]

@chamilis - The individual source patches for my PPA kernels are available in my git trees. See the links to my Ubuntu Maverick and Natty git trees in the "PATCHES / GIT BRANCHES" section in the PPA Description text on the PPA page: https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight . The brightness patches are all those including and above the one called "Backlight: Add backlight type" that you'll see about eight or ten patches down. Note though that the patch sets are pretty complex, and most likely will not apply cleanly to your Debian kernel without some porting effort. You may also be interested in examining or using the linux 2.6.38-target variant(s) of the Matthew Garrett patches, from which some of my PPA patch set are derived. You can find those by searching the 'intel-gfx' mailing list archives (again, for "Backlight: Add backlight type"). Be aware that these patches have not yet been accepted by the Linux mainline kernel.

[chamilis (chamilis)]

Kamal:
Many thanks for your patience and help. I was able to find the patches as you instructed me. I applied the ones from natty on linux-2.6.38-rc6 sources from Debian repositories (package linux-source-2.6.38-rc6). All the patches succeded at once except for the one called "drm/i915/panel: Fix application of legacy backlight value" (on file drivers/gpu/drm/i915/intel_panel.c). The kernel was compiled and installed without problems.
/sys/class/backlight/intel_backlight interface was created and works fine at the moment. It was necessary to use "acpi_backlight=vendor" parameter to use the hotkeys. I'm using a Dell Studio 1558 with intel graphics by the way.
I will try to apply the patches on current stable release linux-2.6.37 and make "intel_panel.c patch" work.
Please let me know if I should paste my results in a different place, since this is an Ubuntu bug report and I'm working on Debian.

[Andy Ross (andy-plausible)]

Can I ask what the upstream status of these patches are? I just had to replace my (broken, and now out of production) 1558 with a new Arrandale laptop (a Dell L501X / "XPS 15"), and was amused to discover that it, too, needs the intel_backlight patch.

This has been a long-standing issue, spanning three Ubuntu versions (including Natty) and 7 kernel releases. It affects *many* machines, and given the crushing weight of the comments in this thread appears to have had very extensive testing.

So what's the holdup? Why isn't this in mainline, or at the very least in Ubuntu's default kernel?

[jorgejhms (jorgejhms)]

Yeah, it should be included at least in the Ubuntu kernel version, or
have a special PPA with the pach. I think there are other issues with
Dell machines in a PPA but there isn't available for Lucid.

[Kamal Mostafa (kamalmostafa)]

Good questions, Andy.

> Can I ask what the upstream status of these patches are?

Upstream status: Unfortunately, the core patches which enable the new intel_backlight did not make it into the upstream Linux 2.6.38 mainline kernel (soon to be released). The patches will likely get re-submitted for consideration for the next mainline kernel version. I will continue to encourage the upstream teams to finalize and adopt the patches.

> So what's the holdup? Why isn't this in mainline, or at the very least in Ubuntu's default kernel?

Ubuntu status: While it is true that many of us have had successful results with my PPA, the patch set (as backported to Maverick at least) is known to cause regressions on a few systems. I do not feel that these patches are suitable for inclusion in the Ubuntu main kernel yet. After they (eventually) land in the Linux mainline kernel I expect that they will stabilize quickly, and at that time I will port and propose them for inclusion in all the currently supported Ubuntu versions.

In the meantime, I will continue to maintain my PPA, which I update regularly to reflect new variants of the core backlight patch set and other related brightness control fixes:
https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

Thanks for your continued patience folks.

[Kamal Mostafa (kamalmostafa)]

My backlight PPA at https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight has been updated with a revised version of the experimental backlight control patches.

This version also includes various upstream Intel GPU driver changes, and sets the kernel parameter "acpi_backlight=vendor" internally (there is no longer any need to set the parameter to enable the new intel_backlight functionality). A couple of additional kernel boot parameters have also been added for testing/troubleshooting purposes -- see the updated notes on the PPA page for details.

The PPA supports Ubuntu Maverick (10.10) and Ubuntu Natty (11.04 alpha).
   *[pending resolution of a build problem with the Natty version]

Users who experience any problems with the PPA version contact me or post here.

[jorgejhms (jorgejhms)]

Dear Kamal,

This PPA also fix this bug
https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/656745
This is the only reason I'm restraining myself to upgrade to maverick
and staying in lucid, being unable to use your pacth...

Regards!

[Prateek Karandikar (prateek.karandikar)]

I have the same issue on my Dell Inspiron 14 R (N4010), on Kubuntu 10.10 64-bit, with the 2.6.35-27-generic kernel, i915 kernel module for graphics. I can move the brightness slider in the battery applet but that has no effect on the brightness. Will this be fixed in 11.04?

[The Amigo (theamigo)]

Thank you very much, Kamal!

This fixes the backlight controls on my Dell Studio 1558 (Core i5 integrated GPU). I run ArchLinux, but the patch applied to a vanilla 2.6.38 kernel without issue and works great.

Here's to hoping that it makes it in 2.6.39 mainline.

[Andrea V (andreakarimodm)]

Just patched a vanilla 2.6.38 kernel on dell laptop XPS 15 running Slackware 13.37.
The intel_brightness interface works great!
Just to let it be used within kde I've written two trivial utilities:

brightness_workaround.pl
------------------------------------
#!/usr/bin/perl

open(ACTUAL, "/sys/class/backlight/intel_backlight/actual_brightness");
$ag = <ACTUAL>;
close(ACTUAL);
$step = ($ARGV[1]) ? $ARGV[1] : 400;
$ag += ($ARGV[0] eq '-') ? -$step : $step;
system("/bin/echo $ag >/sys/class/backlight/intel_backlight/brightness");
------------------------------------

brightness_workaround_wrapper (setuid'ed)
------------------------------------
#include <unistd.h>

int main(int argc, char **argv) {
        setuid(0);
        execv("/usr/local/bin/brightness_workaround", argv);
}
------------------------------------

[Andrea V (andreakarimodm)]

Thanks KAMAL!

[anypundit (adam-anypundit)]

My Acer Aspire 5734 laptop had this problem upon upgrading to Natty beta 1. The above patch worked, but the display still shuts off (not just black with a cursor) for a full 30 seconds during boot. Pre-dist-upgrade I was booting in 30 secs total. I can only hope this will get better?

[Hendy Irawan (ceefour)]

Dear Kamal,

Could you please also look at Bug #538256 ?

It's the exact same issue but for Lenovo IdeaPad net/notebooks including Z360.

Your kernel PPA works but only in GNOME. I use Ubuntu Maverick 10.10 + KDE 4.6.0 from KDE PPA and brightness control doesn't work at all.

[Nicholas Peralta Leon (npl54)]

Hi Kamal

I'm try to installing PPA dedicated to dell studio 15xx in my studio 1558 but when I try to download sources the update manager says;

Failed to fetch http://ppa.launchpad.net/kamalmostafa/linux-kamal-mjgbacklight/ubuntu/dists/lucid/main/binary-i386/Packages.gz 404 Not Found
Some index files failed to download, they have been ignored, or old ones used instead.

I'm trying to change of a another server without result

My location is in south america exactly in colombia.

thanks

[Kamal Mostafa (kamalmostafa)]

@AndreaV - Thanks for contributing those scripts!

@adam - its unlikely that the backlight brightness patch would affect the boot time of your Natty system -- its possible that the issue you're experiencing relates to something else in the (fast moving) Natty beta kernel. If you can determine whether the problem you're seeing is actually specific to the backlight PPA versus the same (non-PPA) version of the Natty kernel, please let me know (you can use 'uname -a' to examine the exact versions of the kernel's you're using).

@Hendy, @Prateek - I understand that the PPA doesn't provide a fully functional solution for KDE yet. I will be re-examining the KDE situation soon.

@Nicholas - The PPA is suitable for Ubuntu Maverick and Natty (but not for Lucid, which you appear to be running). You'll have to upgrade to Maverick if you wish to use the PPA.

[Kamal Mostafa (kamalmostafa)]

Upstream status:

I am happy to report that most of the core backlight brightness patches we've been waiting for (Matthew Garrett's work) have been integrated in the the mainline Linux 2.6.39 kernel source repository. This means that the new "intel_backlight" functionality will now get the necessary testing coverage required before we can pull them in to the official Ubuntu kernel. (One necessary patch has not yet been integrated; I am working with the author to get that missing piece resolved.)

Ubuntu Natty 11.04 (which includes kernel version 2.6.38) will *not* include these patches at release, a few weeks away. I will be working on getting these latest mainline patches backported, aiming to get them included in an official Stable Release Update kernel for Natty (and Maverick, hopefully).

I will continue to maintain the PPA https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight for Natty and Maverick in the meantime.

Thanks again to everyone who has provided testing feedback.

[jorgejhms (jorgejhms)]

Dear Kamal, many of us can't upgrade because of this bug
https://bugzilla.redhat.com/show_bug.cgi?id=624212.
Could't be another option for Lucid users?
--
Jorge Meneses

http://jorgejhms.lamula.pe

2011/4/5 Kamal Mostafa <email address hidden>

> @AndreaV - Thanks for contributing those scripts!
>
> @adam - its unlikely that the backlight brightness patch would affect
> the boot time of your Natty system -- its possible that the issue you're
> experiencing relates to something else in the (fast moving) Natty beta
> kernel. If you can determine whether the problem you're seeing is
> actually specific to the backlight PPA versus the same (non-PPA) version
> of the Natty kernel, please let me know (you can use 'uname -a' to
> examine the exact versions of the kernel's you're using).
>
> @Hendy, @Prateek - I understand that the PPA doesn't provide a fully
> functional solution for KDE yet. I will be re-examining the KDE
> situation soon.
>
> @Nicholas - The PPA is suitable for Ubuntu Maverick and Natty (but not
> for Lucid, which you appear to be running). You'll have to upgrade to
> Maverick if you wish to use the PPA.
>
> --
> You received this bug notification because you are a direct subscriber
> of the bug.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscribe
>

[jorgejhms (jorgejhms)]

I'm sorry, I mean this bug
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/656745
--
Jorge Meneses

http://jorgejhms.lamula.pe

2011/4/5 <email address hidden> <email address hidden>

> Dear Kamal, many of us can't upgrade because of this bug
> https://bugzilla.redhat.com/show_bug.cgi?id=624212.
> Could't be another option for Lucid users?
> --
> Jorge Meneses
>
> http://jorgejhms.lamula.pe
>
>
>
> 2011/4/5 Kamal Mostafa <email address hidden>
>
>> @AndreaV - Thanks for contributing those scripts!
>>
>> @adam - its unlikely that the backlight brightness patch would affect
>> the boot time of your Natty system -- its possible that the issue you're
>> experiencing relates to something else in the (fast moving) Natty beta
>> kernel. If you can determine whether the problem you're seeing is
>> actually specific to the backlight PPA versus the same (non-PPA) version
>> of the Natty kernel, please let me know (you can use 'uname -a' to
>> examine the exact versions of the kernel's you're using).
>>
>> @Hendy, @Prateek - I understand that the PPA doesn't provide a fully
>> functional solution for KDE yet. I will be re-examining the KDE
>> situation soon.
>>
>> @Nicholas - The PPA is suitable for Ubuntu Maverick and Natty (but not
>> for Lucid, which you appear to be running). You'll have to upgrade to
>> Maverick if you wish to use the PPA.
>>
>> --
>> You received this bug notification because you are a direct subscriber
>> of the bug.
>> https://bugs.launchpad.net/bugs/568611
>>
>> Title:
>> Screen brightness control fails on Dell Studio 1558
>>
>> To unsubscribe from this bug, go to:
>> https://bugs.launchpad.net/null/+bug/568611/+subscribe
>>
>
>

[Sarwagya Pandey (sarwagya)]

@kamal,

I am using Ubuntu Lucid 10.04 in my Dell studio 1558 and having the same problem with my brightness controls not working.

I tried to follow the steps that you mentioned but seems like I lost somewhere.

Here is what I did. Can you please tell me where things went wrong?

1) First downloaded the *.deb files from this url
http://kernel.ubuntu.com/~kamal/i915_brightness/latest-lucid/
2) Ran this command: sudo dpkg -i linux*kamal*.deb
Only the linux...all.deb file ran successfully. Other files gave this error
package architecture (amd64) does not match system (i386)

3) After reboot, output of "dmesg | grep backlight" gives nothing.

I am kind of a newbie and just know basic scripting. So can you please guide me in detail how to fix this problem please.

Thanks.

[Nicholas Peralta Leon (npl54)]

Dear Kamal

how could I change the contrast of my screen directly in the driver using something like :

echo "value" > / driver/..

or any other sentence, I propose this like a solution quick because my studio don't allows a upgrade right now until the vacations. My laptot is a dell studio 1558 runing in lucid lynx with linux 2.6.32.30

Thanks .

[Mark Huijgen (mark-sf-net)]

Hi Kamal,

Your patched kernel allows brightness control to work on a new Medion Akoya E7216 laptop where the ACPI brightness implementation fails, so thats great! Thanks for the work you have done to make this work on this system.

However I would like to use the same kernel also another range of systems and these systems need the acpi_video method to control the backlight. This gets completely disabled at the moment because of the forced acpi_video=vendor in drivers/acpi/video_detect.c. The system in question does register an msi-wmi backlight handler now with this new kernel, but this one is not working, only the acpi_video method works on this system.

Is there a way to get brightness controls working on both systems without using different kernel boot parameters? So the intel stystem using intel_backlight (and not the acpi_video) and the other system using acpi_video (and not msi-wmi)?

[Rodrigo M. R. Avila (rodmra)]

Hi Kamal,

still doesn't work for me. I have an Acer travelmate 4230-6704 and can't change lcd brigthness. My Fn key is not working too (keyboard problem).

tried
echo -n 100 > /proc/acpi/video/VGA/LCD/brightness
sudo setpci -s 00:02.0 F4.B=FF

I'm using
Ubuntu Natty with gnome-power-manager version 2.32.0-2ubuntu2+kamal~backlight2~n and linux kernel 2.6.38-8.41+kamal~mjgbacklight3.

lspci
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

lsmod | grep ^i915
i915 515415 3

rodmra@tm4230:/proc/acpi$ ls
ac_adapter battery button event wakeup

rodmra@tm4230:/sys/class/backlight$ ls
intel_backlight

rodmra@tm4230:/sys/class/backlight/intel_backlight$ ls
actual_brightness brightness max_brightness subsystem uevent
bl_power device power type

Thanks.

[Andrea V (andreakarimodm)]

I've noticed a bug with the 2.6.38 patched kernel:
when the backlight is powered off by a power managemente agent, it can't be lightened on again!
Also with:

$ xset dpms force off

turns the screen off but it cannot be lightened back! The computer still perfectly working, but no screen!

With vanilla the problem doesn't present itself.

[Wolfgang Kufner (wolfgangkufner)]

Same problem. The patched kernel makes backlight control work again on an Acer Extens 5635Z (bug 518002), but if I close the lid it does not come back on again. Not even with setpci. Tested with both kernels on maverick.

[Wolfgang Kufner (wolfgangkufner)]

Another user (bug 773471 comment 15) reports yet different strange side effects: It only works till he moves the mouse.
quote:
>yes till the first mouse move...the backlight hotkeys work!!!!i can bring it back with setpci...its ok for me to close the lid and after >xset dpms force off, press a key is enough, brightness comes back!

uname -a
Linux chris-Aspire-5732Z 2.6.38-9-generic #43+kamal~mjgbacklight4-Ubuntu SMP Fri Apr 29 04:31:32 UTC 2011 i686 i686 i386 GNU/Linux

ls /sys/class/backlight
intel_backlight

[Wolfgang Kufner (wolfgangkufner)]

Correction for comment 188: With the Extensa from bug 518002 the problem is just that after lid close or xset dpms force off the backlight does not come on again with any keypress like it should. Instead I have to use the hotkeys to up the brightness from zero to what I want. Which is kind of annoying since it is every time after a lid close. Still, way less severe than I mistakenly thought.

Correction for comment 189: With the Acer from bug 773471 everything works.

[J. Austin Rodriguez (jeanaustinr)]

The temporary workaround works for HP Pavilion dv3-2016t running Ubuntu 11.04. Thank you!

[Kenneth Thorell (kenneth-thorell)]

Hi all
I used this "https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight"
to mi Acer eMashines G525 and it works but the LCD brightness is going backwords
So i set my LCD brightness to 3 % and then itś working

this is from the bug report https://bugs.launchpad.net/ubuntu/+source/linux/+bug/765438
 hope that you can patch a new file with the LCD light going in the right way

"i don t know how to use "uname -a" and copying it to this"

But is a ACER eMashines G525 runing 64 bit 11.04

[Kamal Mostafa (kamalmostafa)]

Addressing several recent posts regarding the linux-kamal-mjgbacklight PPA:
https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

A few of you have reported problems with the backlight not coming back on after power management / lid events (or after 'xset dpms force off')... It is not clear whether this problem is specific to the linux-kamal-mjgbacklight PPA kernel or a new problem introduced in the mainline 11.04 kernel (as suggested by bug 765438). Those experiencing this problem: Please advise whether booting with the parameter "i915.alse_backlight=1" affects it (and also whether that parameter adversely affect the normal backlight control, which it might).

The "inverted brightness controls" problem reported on some Acer systems (Acer TravelMate, Acer eMachines G525) is a known issue and is being investigated.

Some users have asked whether these backlight patches can be applied to Ubuntu 10.04 (Lucid): No. The linux-kamal-mjgbacklight PPA is only applicable to Ubuntu 10.10 (Maverick) and Ubuntu 11.04 (Natty). I do not expect that this work will be ported to Lucid or earlier releases due to technical incompatibilities.

Upstream status of the patch set: We are still waiting for one (critical) patch to be applied to the upstream linux kernel before we can integrate this functionality into the main Ubuntu kernel. Until such time, I will continue to maintain up-to-date Maverick and Natty kernels including the patches at the PPA linked above.

[Peter-jezdec (peter-jezdec)]

Hi, I have a dell inspiron N7010, and this PPA fixed my backlight problem in Maverick; however, not in natty. The backlight interface is created, but is not controled by Gnome 2.32.1.

uname -a
Linux Rebuild 2.6.38-9-generic #43+kamal~mjgbacklight4-Ubuntu SMP Fri Apr 29 04:33:59 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

with dell_laptop.backlight=0
ls /sys/class/backlight/
intel_backlight

without dell_laptop.backlight=0
ls /sys/class/backlight/
dell_backlight intel_backlight

if I write a value to /sys/class/backlight/intel_backlight/brightness, the backlight does change

[Peter-jezdec (peter-jezdec)]

Apparently, the update from maverick to natty caused Gnome power management to be removed. I installed it, and now the power keys, etc. work.

[Wolfgang Kufner (wolfgangkufner)]

i915.alse_backlight=1 result:
no more hotkeys (full bright, which is always the default)
immediately bright again after lid open (instead of black that I can regulate up with hotkeys)
/sys/class/backlight/ empty (instead of intel_backlight without parameter)
also:
unknown parameter i915.alse_backlight at bootup
screen resolution is much lower

with:
Acer Extensa 5635Z from bug 518002 and comment 190
maverick with patched 2.6.38-9 and xorg-edgers

Thanks

[Andrea V (andreakarimodm)]

i915.alse_backlight=1 doesn't have any significant effect for me.
Brightness can be lightened on again only with hotkeys (brightness_workaraound.pl script associated to Fn Keys).

[Andrea V (andreakarimodm)]

I've discovered a slight difference with i915.alse_backlight=1:
the actions over the intel_backlight interface (script associated with key combination [ echo NUM >intel_backlight ]) can reestablish a correct screen brightness while without that kernel parameters, those same actions, seem to be ignored!

[[e-mail] (abuazooz)]

when I use $ lsmod | grep ^i915 in terminal it shows command not found

Linux ubuntu 2.6.39-0-generic #5~20110427-Ubuntu SMP Wed Apr 27 15:27:41 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

[aaronchall (aaronchall)]

I have the studio 1558, brightness control problem going on.

I added the repository with:
sudo add-apt-repository ppa:kamalmostafa/linux-kamal-mjgbacklight/ppa

Then I did:
sudo apt-get update

It still wouldn't work, so I ran this:
sudo apt-get dist-upgrade

I guess I'll reboot, and see if it works.

Aaron

PS I noticed I could "manually" add the ppa with this:
deb http://ppa.launchpad.net/kamalmostafa/linux-kamal-mjgbacklight/ubuntu maverick main
deb-src http://ppa.launchpad.net/kamalmostafa/linux-kamal-mjgbacklight/ubuntu maverick main

How is that different from what I've done?

[Marcin Juszkiewicz (hrw)]

ASUS UL30A running oneiric with 2.6.38-9-generic amd64 kernel:

[ 0.000000] Linux version 2.6.38-9-generic (buildd@king) (gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4) ) #43+kamal~mjgbacklight4-Ubuntu SMP Fri Apr 29 04:33:59 UTC 2011 (Ubuntu 2.6.38-9.43+kamal~mjgbacklight4-generic 2.6.38.4)

Pressing Fn+F6 (Brightness Up) is catched by XFCE and notification for brightness up is shown. But brightness does not change and kernel says:

[ 803.043216] ACPI Error: Result stack is empty! State=ffff880134fc4800 (20110112/dswstate-98)
[ 803.043236] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110112/dsutils-646)
[ 803.043247] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110112/dsutils-763)
[ 803.043261] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.UPBL] (Node ffff880137638550), AE_AML_NO_RETURN_VALUE (20110112/psparse-536)
[ 803.043284] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0F] (Node ffff88013763fcd0), AE_AML_NO_RETURN_VALUE (20110112/psparse-536)

On Fn+F5 (Brightness Down):

[ 833.535486] ACPI Error: Result stack is empty! State=ffff88012f7c7800 (20110112/dswstate-98)
[ 833.535505] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110112/dsutils-646)
[ 833.535517] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110112/dsutils-763)
[ 833.535531] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.DWBL] (Node ffff880137638578), AE_AML_NO_RETURN_VALUE (20110112/psparse-536)
[ 833.535554] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0E] (Node ffff88013763fca8), AE_AML_NO_RETURN_VALUE (20110112/psparse-536)

Now I have two backlight interfaces:

17:01 root@lucek:backlight# ls -l
razem 0
lrwxrwxrwx 1 root root 0 2011-05-20 16:47 asus_laptop -> ../../devices/platform/asus_laptop/backlight/asus_laptop
lrwxrwxrwx 1 root root 0 2011-05-20 16:47 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

Removing of asus-laptop module gave me black screen with no backlight at all. Loading it back does not change situation.

Amount of possible step for intel_backlight scares me:

17:03 root@lucek:intel_backlight# cat max_brightness
1992060

[J. Austin Rodriguez (jeanaustinr)]

Is there a way like somehow apply it to Fedora 15? Something like a conversion tool from deb to rpm?

[Helias Fotiadis (heliasfotiadis)]

I have an emachines E525 laptop and I have been experiencing problems with my screen backlight since I installed Natty.
I have installed the patched kamal mostafa kernel and my problem symtoms now are:
1) no backlight at startup but fixable with the hotkeys
2) the inverted hotkeys.
3) the comptuter cannot be controlled when I return from suspension, showing me a black (but with brightness active) screen with the mouse pointer swimming in it aimlessly or showing nothin at all, making me to press and hold the power button down to restart the computer. Rarely, though, it works fine. But realy rarely. This is not the case with hibernation, however, which works fine.
AND
3)when I use the laptop battery to turn my computer on the backlight is off during the "Ubuntu" starting/welcoming screen as always but just before that screen switches to my desktop screen the backlight is on and I can see the starting screen (only briefly) and then my desktop screen. However, this is NOT happening when the laptop is on main power source whether it is only main or I recharge the battery. This is happening only on battery alone. Also when I press the brightness hotkey it shows me that the brighness bar is halfway full.
Now, when I use the i915.alse_backlight=1 parameter on GRUB the following happen:
1) I have full brightness from the beginning, no problems at all with that.
2) the hotkeys for brightness don't work.
3) the return from suspension still messes up my computer....hibernation works fine.
4) whether the power source is main or battery or both it does't make any difference.
5) the screen is somewhat messed up meaning that it's annoyingly wide.

On all cases, closing the lid makes no problems because I have changed the option so the computer does nothing when I close the lid.

[Jean-Sebastien Gosselin (jsgosselin)]

On a Laptop Dell Inspiron 14R with Ubuntu 11.04 64bit, blacklight control is working as intended with the patched kamal mostafa kernel. Thank you very much.

I had similar issue though with the screen lock when returning from suspension or from screen saver; my screen was randomly freezing, but I was able to move the mouse around. I had to Ctrl-Alt F2 and "sudo pkill X" in order to have it back.

I deactivated in CompizConfig Settings Manager>General>OpenGL>Sync To VBlank and the issue seems to be resolved.

JS

[Andrea V (andreakarimodm)]

@Kamal Mostafa: any mainline-related updates?

[Barry Lennon (monkeysinablender)]

I'm a complete newcomer to Ubuntu (and Linux in general), but I can immediately see the improvements in using my netbook with it over Win7.

That said, I'm having the same display brightness problems as above.

I can use the workaround for "setpci", but I can't get the PPA working. It shows up as an entry named "linux-kamal-mjgbacklight" in the Ubuntu Software Centre application, but the "intel_backlight" entry isn't there when I run $ ls /sys/class/backlight (there's nothing in there now - it used to list the default).

I'm using a Samsung N210. The output for $ uname -a is "Linux Samtu 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC 2011 i686 i686 i386 GNU/Linux".

Am I even meant to be using this patch on this machine?? Any help gratefully received.

[Jean-Sebastien Gosselin (jsgosselin)]

@Barry Lennon

Hello Barry. Here is what I did to install this ppa: I added it to my software sources in update manager (in "other software" tab), than ran an update of my system (also in update manager) and it installed everything all by itself.

I also suggest you read this: https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

It will probably help you determine if this ppa is well suited for your system.

[Kamal Mostafa (kamalmostafa)]

Upstream status of the patch set: No change in status as of upstream Linux v3.0-rc4.... We are still (yes, still!) waiting for one critical patch to be applied to the upstream linux kernel before we can integrate this functionality into the main Ubuntu kernel. Until such time, I will continue to maintain up-to-date Maverick and Natty kernels including the patches at the PPA linked above.

[jorgejhms (jorgejhms)]

Could you send the link for the bug upstream? Thanks!
--
Jorge Meneses

http://jorgejhms.lamula.pe

2011/6/21 Kamal Mostafa <email address hidden>

> Upstream status of the patch set: No change in status as of upstream
> Linux v3.0-rc4.... We are still (yes, still!) waiting for one critical
> patch to be applied to the upstream linux kernel before we can integrate
> this functionality into the main Ubuntu kernel. Until such time, I will
> continue to maintain up-to-date Maverick and Natty kernels including the
> patches at the PPA linked above.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscriptions
>

[Marcin Juszkiewicz (hrw)]

Asus UL30A again.

11:40 root@lumpek:intel_backlight# uname -a
Linux lumpek 2.6.38-10-generic #44+kamal~mjgbacklight4-Ubuntu SMP Mon Jun 6 19:40:12 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

/sys/class/backlight/
11:38 hrw@lumpek:backlight$ ll
razem 0
lrwxrwxrwx 1 root root 0 2011-06-28 11:36 asus_laptop -> ../../devices/platform/asus_laptop/backlight/asus_laptop
lrwxrwxrwx 1 root root 0 2011-06-28 11:36 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

11:42 root@lumpek:intel_backlight# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-2.6.38-10-generic root=/dev/mapper/lucek-rootfs ro loop.max_loop=256 loglevel=9

After removing 'asus_laptop' module I had backlight working fine with your kernel. With oneiric kernel I have backlight working fine with asus_laptop module loaded.

[Marcin Juszkiewicz (hrw)]

Also when 'asus_laptop' driver is used with 3.0-2-generic 'oneiric' kernel I got ACPI exceptions when changing backlight level:

Jun 28 11:54:39 localhost kernel: [ 612.337945] ACPI Error: Result stack is empty! State=ffff880103c9ec00 (20110413/dswstate-98)
Jun 28 11:54:39 localhost kernel: [ 612.337963] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110413/dsutils-646)
Jun 28 11:54:39 localhost kernel: [ 612.337975] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110413/dsutils-763)
Jun 28 11:54:39 localhost kernel: [ 612.337987] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.DWBL] (Node ffff880138e38578), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)
Jun 28 11:54:39 localhost kernel: [ 612.338009] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0E] (Node ffff880138e3fca8), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)

Jun 28 11:54:42 localhost kernel: [ 615.157385] ACPI Error: Result stack is empty! State=ffff880103c9f400 (20110413/dswstate-98)
Jun 28 11:54:42 localhost kernel: [ 615.157403] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110413/dsutils-646)
Jun 28 11:54:42 localhost kernel: [ 615.157415] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110413/dsutils-763)
Jun 28 11:54:42 localhost kernel: [ 615.157428] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.UPBL] (Node ffff880138e38550), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)
Jun 28 11:54:42 localhost kernel: [ 615.157450] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0F] (Node ffff880138e3fcd0), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)

No such messages when intel_backlight is used.

[Joshua Rubin (rubixconsulting)]

Any news on when the #46 kernel will be built?

[Kamal Mostafa (kamalmostafa)]

I have just uploaded the latest Maverick 2.6.35-30.56 and Natty linux_2.6.38-10.46 kernels to the PPA:
https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight
(the packages are queued and should build some time in the next several hours).

Still no change in upstream status as of Linux 3.0-rc7.

[Drew (drewwells)]

Kamal, your ppa worked awesome (using Gnome3/2.6.38-10.46).

Pavilion dv6 'Quad Edition' Hybrid Graphics

Brightness controls worked on the Radeon 6740 side and Intel side.

[chamilis (chamilis)]

Kamal, I've seen that there haven't been updates on the patches source code for a while, the last one is for kernel 2.6.38. Are the patches anywhere else?

[Joshua Rubin (rubixconsulting)]

Yeah, I don't want to keep bugging you either, but 2.6.38-11 #48 kernel from proposed is currently overriding the latest backlight fix kernel (2.6.38-11 #47)

[Kamal Mostafa (kamalmostafa)]

Good news to report from upstream... the last of Matthew Garrett's backlight brightness patches has seen some renewed activity on the intel-gfx mailing list[1]. I expect the latest version of the patch[2] (targeted for linux kernel version 3.1) to be merged into the mainline trees soon.

I have applied this latest version of the backlight patch to my PPA kernels for Oneiric and Natty (Maverick still uses the older backlight patches). The PPA kernels have also all been updated to the latest Ubuntu kernel baseline versions. The PPA builds are in progress and should become available in the next several hours:

    https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

My git source trees for these kernels have also all been updated (see the links to them on the PPA page).

[1] http://comments.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/5368
[2] http://permalink.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/5434

[jorgejhms (jorgejhms)]

Esta muyy bueno, que salga de una vez!!!
--
Jorge Meneses

http://jorgejhms.lamula.pe

2011/8/12 Kamal Mostafa <email address hidden>

> Good news to report from upstream... the last of Matthew Garrett's
> backlight brightness patches has seen some renewed activity on the
> intel-gfx mailing list[1]. I expect the latest version of the patch[2]
> (targeted for linux kernel version 3.1) to be merged into the mainline
> trees soon.
>
> I have applied this latest version of the backlight patch to my PPA
> kernels for Oneiric and Natty (Maverick still uses the older backlight
> patches). The PPA kernels have also all been updated to the latest
> Ubuntu kernel baseline versions. The PPA builds are in progress and
> should become available in the next several hours:
>
> https://launchpad.net/~kamalmostafa/+archive/linux-kamal-<https://launchpad.net/%7Ekamalmostafa/+archive/linux-kamal->
> mjgbacklight
>
> My git source trees for these kernels have also all been updated (see
> the links to them on the PPA page).
>
> [1]
> http://comments.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/5368
> [2]
> http://permalink.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/5434
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscriptions
>

[Perry Werneck (perry-werneck)]

Hi,

Just to inform the patch is working fine in a Samsumg RV410, who was showing a very dark screen before it.

[bcbc (bcbc)]

I'm running Oneiric, Dell 14R N4010
Since applying the patch, the brightness keys work, but only to toggle the screen off and on.

I tried adding the boot option "dell_laptop.backlight=0" but it didn't make a difference. Before I added that boot option I had a dell_backlight entry in /sys/class/backlight along with intel_backlight, but it's now I only see the intel_backlight entry.

bcbc@ubuntu:~$ uname -a
Linux ubuntu 3.0.0-8-generic #11+kamal~mjgbacklight5-Ubuntu SMP Fri Aug 12 23:53:11 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
bcbc@ubuntu:~$ ls /sys/class/backlight
intel_backlight
bcbc@ubuntu:~$

Here is the line from my grub.cfg:
linux /boot/vmlinuz-3.0.0-8-generic root=UUID=18B4B7BBB4B799A8 loop=/ubuntu/disks/root.disk ro crashkernel=384M-2G:64M,2G-:128M quiet splash dell_laptop.backlight=0 vt.handoff=7

PS your Natty patch worked great on this computer.

[Jorge G (geojorg)]

I am on Oneiric Dell 14R N4010.

The latest kernel only allows to toggle on or off the backlight, i think it has something to do with the new power manager in Gnome 3.

Would Gnome Power Manager 3 be patch against this ?

[Jorge G (geojorg)]

The hotkeys for brightness control don't work correctly. Brightness can only be controlled using the new Screen system in the new Gnome Control Center.

[Kamal Mostafa (kamalmostafa)]

I have identified and fixed the cause of the "toggles backlight on or off" problem in Ubuntu Oneiric [ reference https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/827517 ]. My backlight PPA https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight now supplies a fixed gnome-settings-daemon package for Oneiric. This issue only affects the gnome-settings-daemon package in Gnome3, so it is not relevant to Ubuntu Maverick or Natty. Thanks bcbc and Jorge G for reporting the problem.

Side note: I have also updated the gnome-power-manager package for Natty -- just picking up the latest baseline changes.

[Joshua Rubin (rubixconsulting)]

Using 2.6.38-11-generic #48+kamal~mjgbacklight5-Ubuntu, on a Studio 1558, the backlight keys work (I see the notification), but the backlight levels are no longer changing.

[Joe Maillard (xxtoocoolxx)]

I have a fresh install on natty on my Dell Studio 1558, The brightness keys do NOT work with the last PPA update with kernel 2.6.38-11.

If I boot with the previous kernel the brightness keys work as expected. 2.6.38-10-generic-pae #46+kamal~mjgbacklight4-Ubuntu SMP Fri Jul 15 03:10:48 UTC 2011 i686 i686 i386 GNU/Linux

I have been following your fixes since Oct when I retired my Debian workstation and switched to using Ubuntu on my laptop.

Thanks for your ongoing help,

Joe

[Kamal Mostafa (kamalmostafa)]

I have uploaded a revised Natty kernel to the PPA, which should fix the regression some users have reported since the last update (this revision re-instates the enabling of acpi_backlight=vendor parameter by default). The new 'kamal2' Natty kernel (linux - 2.6.38-11.48+kamal2~mjgbacklight5) is queued to build and should become available within the next several hours. Thanks Joshua, Joe, and Lawrence for reporting and helping to diagnose the problem.

    https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

(Its unclear whether Oneiric also needs "acpi_backlight=vendor"; I'll apply the same fix there if any Oneiric user of the backlight PPA advises me that booting with that kernel parameter fixes their system).

[bcbc (bcbc)]

I've just updated on Oneiric 14R N4010. The brightness keys are now working without any kernel boot options:

bcbc@ubuntu:~$ uname -a
Linux ubuntu 3.0.0-8-generic #11+kamal~mjgbacklight5-Ubuntu SMP Fri Aug 12 23:53:11 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
bcbc@ubuntu:~$ ls /sys/class/backlight
dell_backlight intel_backlight
bcbc@ubuntu:~$

The only thing is that when the function keys are pressed, the popup display show a computer with a solid bar underneath that doesn't change, however, if I go to System settings, Screen, the slider works appropriately.

As far as I am concerned, this is working great. Thank you for your effort to get this fixed and also providing the ppa's.

[Kamal Mostafa (kamalmostafa)]

I'm very pleased to announce that the last of Matthew Garrett's backlight patches has been merged into the upstream Linux tree[1] and the Ubuntu Oneiric kernel tree. It should appear in the next official Oneiric kernel release (3.0.0-9.12). As noted previously, some Oneiric systems will likely still need to boot with "acpi_backlight=vendor", and pending resolution of bug 827517 all Oneiric systems will still need to use the gnome-settings-daemon package supplied by my backlight PPA[2]. Further small refinements (fixing the popup display behavior) are likely in the near future.

I will be looking into the plausibility of merging the patch set into the official Ubuntu kernels for Natty and Maverick next, and will continue to support those releases via my PPA in the meantime.

[1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=aaa6fd2a004147bf32fce05720938236de3361d9
[2] https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

[Luciano Dato (lucianodato)]

Great news!!! Thank's for all your work Kamal!

2011/8/17 Kamal Mostafa <email address hidden>

> I'm very pleased to announce that the last of Matthew Garrett's
> backlight patches has been merged into the upstream Linux tree[1] and
> the Ubuntu Oneiric kernel tree. It should appear in the next official
> Oneiric kernel release (3.0.0-9.12). As noted previously, some Oneiric
> systems will likely still need to boot with "acpi_backlight=vendor", and
> pending resolution of bug 827517 all Oneiric systems will still need to
> use the gnome-settings-daemon package supplied by my backlight PPA[2].
> Further small refinements (fixing the popup display behavior) are likely
> in the near future.
>
> I will be looking into the plausibility of merging the patch set into
> the official Ubuntu kernels for Natty and Maverick next, and will
> continue to support those releases via my PPA in the meantime.
>
> [1]
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=aaa6fd2a004147bf32fce05720938236de3361d9
> [2] https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight<https://launchpad.net/%7Ekamalmostafa/+archive/linux-kamal-mjgbacklight>
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/568611
>
> Title:
> Screen brightness control fails on Dell Studio 1558
>
> Status in NULL Project:
> Invalid
> Status in “alsa-driver” package in Ubuntu:
> Invalid
> Status in “linux” package in Ubuntu:
> Fix Committed
>
> Bug description:
> Attempts (on a current Lucid beta) to control the screen brightness on
> my Dell Studio 1558 fail with the following errors reported in dmesg:
>
> [ 1162.236365] ACPI: Failed to switch the brightness
> [ 1162.379144] ACPI: Failed to switch the brightness
> [ 1162.538226] ACPI: Failed to switch the brightness
> [ 1162.667358] ACPI: Failed to switch the brightness
> [ 1162.784171] ACPI: Failed to switch the brightness
>
> This is true both for the keyboard's brightness controls (Fn-F4,
> Fn-F5) and for a gnome-brightness-applet on the panel.
>
> Output of acpidump, dmesg and lspci is attached.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/null/+bug/568611/+subscriptions
>

--
Luciano Dato

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.0.0-9.12

---------------
linux (3.0.0-9.12) oneiric; urgency=low

  [ Andy Whitcroft ]

  * [Config] standardise CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=m
  * [Config] move ECRYPT_FS back to =y for all architectures
    - LP: #827197
  * record the compiler in the ABI and check for inconsistant builds

  [ Leann Ogasawara ]

  * Revert "SAUCE: OMAP: DSS2: enable hsclk in dsi_pll_init for OMAP36XX"
  * Revert "SAUCE: OMAP: DSS2: check for both cpu type and revision, rather
    than just revision"
  * Revert "SAUCE: ARM: OMAP: Add macros for comparing silicon revision"
  * rebase to v3.0.2
  * rebase to v3.0.3
  * Temporarily ignore module check
  * [Config] Set CONFIG_DM_MIRROR=m on amd64, i386, and arm
  * [Config] Set CONFIG_DM_MULTIPATH=m on amd64, i386, and arm
  * [Config] Set CONFIG_DM_SNAPSHOT=m on amd64, i386, and arm
  * [Config] Enable CONFIG_EDAC_AMD8111=m on powerpc
  * [Config] Enable CONFIG_EDAC_AMD8131=m on powerpc
  * [Config] Enable CONFIG_EDAC_CPC925=m on powerpc
  * [Config] Enable CONFIG_EDAC_PASEMI=m on powerpc
  * [Config] Set CONFIG_EFI_VARS=m on amd64 and i386

  [ Stefan Bader ]

  * [Upstream] xen-blkfront: Drop name and minor adjustments for emulated
    scsi devices
    - LP: #784937
  * [Config] Force perf to use libiberty for demangling
    - LP: #783660

  [ Stefano Stabellini ]

  * [Upstream] xen: Do not enable PV IPIs when vector callback not present
    - LP: #791850

  [ Tim Gardner ]

  * [Config] updateconfigs after rebase to 3.0.2

  [ Upstream Kernel Changes ]

  * Not all systems expose a firmware or platform mechanism for changing
    the backlight intensity on i915, so add native driver support.
    - LP: #568611
  * rebase to v3.0.2
  * rebase to v3.0.3
 -- Leann Ogasawara <email address hidden> Mon, 15 Aug 2011 13:35:57 -0700

[AlexW (alex.wedensky)]

dell studio 1558, i3, intel graphics, oneric i386 beta daily build

booting into live environment "as is" (both Unity and KDE) -- brightness keys don't work, brightness sliders in "settings" do nothing.

booting into live environment with "acpi-backlight=vendor" option -- in KDE brightness works as expected (both the keys and the slider); in Unity the keys produce "all or nothing" response, but the slider works correctly.

too early to draw conclusions?

cheers,

alex

[J. Austin Rodriguez (jeanaustinr)]

Thank you Kamal (and everyone) for continuously providing help and solution for this issue. I have one quick question. Although I don't think it's proper to post it here but I assume it's related to the kernel I applied via the PPA. Since installing it, my wireless is disabled and could not be activated (as seen in the screenshot) even when I press the Wifi button. I am using HP Pavilion dv3t, Intel.

I don't remember the changes I made but if anyone could help me figure out which, it would be very much appreciated.

Thank you.

[Adi Roiban (adiroiban)]

Tried today Oneiric with linux-image-generic 3.0.0-9.15

The screen display control turns the screnn On or OFF, there is no intermediate brightness.

[Adi Roiban (adiroiban)]

Sorry for the noise.

Only now I saw comment 228.

I added dell_laptop.backlight=0 to kernel start options and it is now working with the standard Oneiric kernel.

It was not required to use gnome-settings-daemon from the PPA.

Thanks!

[Kamal Mostafa (kamalmostafa)]

[Oneiric Beta users]:

In Oneiric, the behavior "screen brightness keys toggle from max to min-brightness (no steps between)" in the Unity desktop is caused by bug 827517, which is now fixed in the gnome-settings-daemon package in the main Ubuntu archives -- but the fix didn't arrive until just after the Oneiric Beta 1 release. Simply updating your Oneiric system software after installing Beta 1 should pick up the fixed gnome-settings-daemon (version 3.1.90-0ubuntu2 or higher).

As noted previously, some Oneiric systems will still need to boot with "acpi_backlight=vendor" or some other vendor-specific boot parameter to make the brightness up/down keys work at all. See the PPA instructions page for details and additional diagnostic information (even though the PPA is no longer needed for Oneiric systems):
  https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

[Natty and Maverick users]: No news to report.

[Kamal Mostafa (kamalmostafa)]

Latest manzanita natty test kernel is available on blade3:

  binary packages: /srv/kamal/x-2.6.38-11.50+kamal20110920

  git tree: /srv/kamal/ubuntu-natty [manzanita-kamal20110920]

New for this version are the following patches, backported from mainline:

  * ext4: wait for writeback to complete while making pages writable
  * vfs: Create __block_page_mkwrite() helper passing error values back
  * ext4: Rewrite ext4_page_mkwrite() to use generic helpers
  * vfs: Block mmapped writes while the fs is frozen

 -Kamal

-------

linux (2.6.38-11.50+kamal20110920) lucid; urgency=low

  LP: #666581 TEST KERNEL backported to 2.6.38-11.50 (natty)
  - Val patch set 20110914
  - Surbhi journal freeze patches
  - ext4_page_mkwrite fixes from upstream mainline
  - build for lucid

  [ Upstream Kernel Changes ]

  * don't busy retry the inode on failed grab_super_passive()
  * ext4: wait for writeback to complete while making pages writable
  * vfs: Create __block_page_mkwrite() helper passing error values back
  * ext4: Rewrite ext4_page_mkwrite() to use generic helpers
  * vfs: Block mmapped writes while the fs is frozen

  [ Surbhi Palande ]

  * Adding support to freeze and unfreeze a journal
  * Thaw the journal when you unfreeze the fs.

  [ Valerie Aurora ]

  * quota: Release path on error in sys_quotactl()
  * VFS: Fix s_umount thaw/write deadlock
  * VFS: Rename vfs_check_frozen() to vfs_block_until_thawed()
  * Documentation: Correct s_umount state for freeze_fs/unfreeze_fs

 -- Kamal Mostafa <email address hidden> Tue, 20 Sep 2011 15:31:03 -0700

 -Kamal

[bond17_007 (manijshrestha)]

Thanks kamal for your work on this.
I had this issue on Dell 1558 on ubuntu 11.04. I updated to your patch. I thought this was fixed on 11.10, I updated my system to 11.10 yesterday and now my brightness doesn't work anymore :(. The applet shows the bar but notthing happens on the screen.
When I grep the "dmesg" I see following errors:

[ 15.312411] [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness

Can you please let me know if you can release a patch for this or if there is other workaround.

Thanks,

[AlexW (alex.wedensky)]

@bond17_007: my laptop does adjust the brightness when booted with kernel parameter "acpi_backlight=vendor". Funny thing is, neither the brightness nor suspending on lid close work if you log out... there isn't even an option to suspend or hibernate from the "power" menu on the login screen...

[Kamal Mostafa (kamalmostafa)]

Backlight brightness control in Ubuntu 11.10 (Oneiric) -- summary of known remaining issues:

As noted previously, some Ubuntu 11.10 (Oneiric) systems will still need to boot with "acpi_backlight=vendor" or some other vendor-specific boot parameter to make the brightness up/down keys work.

Screensaver blank screen gets stuck off: In Ubuntu 11.10 (Oneiric), users of Dell Studio 15, Dell Studio 1558, and some other models may experience the problem LP: #872652 ("screensaver backlight stuck off, system looks hung"). If you find that your backlight gets stuck off when the screensaver blanks the screen, see that bug number for the fix.

Some (all?) systems with Intel GMA4500-based graphics processors have their brightness controls "inverted" such that the brightness-down key increases the brightness and vice versa. This also results in the system starting with its brightness set to minimum (or even "off") when the system first boots. This problem is tracked by LP: #752165, LP: #765438, LP: #773471.

[J. Austin Rodriguez (jeanaustinr)]

This fix works on my notebook, however, I noticed two things:
1. Whenever I start my computer, the brightness is at its maximum. It does not remember the last settings.
2. When my computer resumes from idle mode, the screen is not turned off, instead, brightness is at its lowest.

How do I fix it? Thanks

(Hats off to everyone for a job well done1)

By the way, my computer is HP Pavilion dv3t.

[Oscar Bidabehere (oscar-bidabehere)]

Hi, my notebook is an HP Pavilion DV7 with a Radeon Hybrid Card. I had Ubuntu 10.04 32bits and the patch Kamal made worked for me using the following kernel Params:
*radeon.modeset=0 (disables radeon discrete card)
*acpi_backlight=vendor (kamal patch)

Now I updated to Ubuntu 11.10 64bits and the patch is supposed to be already in the kernel. The problem is that if I use the second param, I get a black screen almost all of the time, and some few times the systems boots correctly with the brightness control working correctly.

Is there any way to solve this?

I would appreciate it very much!

[Darren Sargent (darrensargent)]

Hi Kamal,

Thanks for your work on the backlight issue.

It was working fine for me with your PPA, until I upgraded to 11.10 (Oneiric). Now it's back to the broken behavior - stuck at maximum, responds to the hotkeys (but only moves up or down a notch then jumps back).

I've tried various combinations of: acpi_backlight=vendor and dell_laptop.backlight=0 in 'grub' to no avail, including not putting them in there (rebooting after each attempt of course).

Here's my info:

Dell XPS 17 L701X (64 bit)

$ cat /etc/issue
Ubuntu 11.10

$ ls /sys/class/backlight/
intel_backlight

$ uname -a
Linux photon 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

--Darren.

[Darren Sargent (darrensargent)]

I just discovered something really odd, by accident: tapping the middle "touch" button on the right of the laptop, the thing that looks like three lines with blobs on the end meeting at a point, dims the backlight as I want -- I can increase the brightness with Fn-F5. It's an odd key combination but it allows me to control the brightness. Hope that helps troubleshoot and as a workaround for others.

[jhs_bg (i-petrov-ca)]

A BIG thank you to all involved, especially Kamal for the tremendous efforts on this!

After one year owning that Dell Studio 1558 I finally can use linux! Freedom!
It works with "acpi_backlight=vendor dell_laptop.backlight=0".
I hated it before because it was burning my eyes with backlight to the max.

For the record, my laptop configuration is:
Intel Core i5
VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)
Full HD display

I could not manage to get the kernel 2.x.x patched and recompiled... It was way easier in the old Slackware days.
Or it is just me getting old...
Anyways, I can't explain how glad I am to see kernel 3 supports the nasty Dell acpi!

Thank you again!
::happy face::
Ivan

[AlexW (alex.wedensky)]

apologies for the noise... but since a lot of 1558 owners still get updates on the activity of this thread:

Am I the only one who doesn't have the Standby/Hibernate capability when logged out of the session? As in, log out of your session, close the lid -- nothing happens; and there's no option to standby or hibernate in the Power menu... (1558, i3, Intel, Kubuntu 11.10 64 bit fully updated).

for the record, 10.04 works as it should with Kamal's patch (_manythanks_)

Alex

[captain toro (commander1oldsmobile)]

Is there a way to have a finer control of the screen brightness?

I have been using the kamal~mjgbacklight kernels for
the /sys/class/backlight/intel_backlight control in my Dell
Studio 1558 since last spring. I now have the kamal~mjgbacklight
kernel in my Sony Vaio All-in-One with 22" display. Both systems
have the 1920x1080 screens and Core i3 CPU with the i915 driver and
the Sony has the same issue with the backlight as the Dell.

Both of these systems have a blinding bright screen and
the intel_backlight control solves those problems. Now I
have tried the acpi_video0 control on the newer kernels and the
result is not good enough.

My current kernel is linux 3.0 and I have both intel_backlight and
acpi_video0. The maximum brightness on the Dell is 4882 for the
intel_backlight and 15 for the acpi_video0 except the acpi_video0
doesn't seem to work for the Dell. The Sony has maximum brightness
of 4687 with the intel_brightness and maximum of 8 with the
acpi_video0 and both can used at the same time. Here is the problem
with the Sony:

ACPI INTEL
0 1066
1 1396
2 1874
3 2334
.
.
8 4687

The settings for acpi_video0 at 4,5,6,7 are too bright for my eyes
to check the numbers and cause a type of blindness after a while.
Most of the time I use the brightness setting of between 300 and 500
with the intel_backlight control because the setting for 0 or 1 on
the acpi_video0 control is just too bright for my eyes.

The problem is the same with Windows 7 where the minimum brightness
is too bright. I think the acpi configuration might be finding the
same settings as for Windows and that is the problem. My solution
is to continue to use the intel_backlight control from the
kamal~mjgbacklight kernel.

Am I missing something here? Are there going to be any more fixes to
the brightness control? I am about to try the linux 3.1 kernel except
doubt the acpi_video0 will give a fine enough control of the brightness.
Should I continue to use the kamal~mjgbacklight fixing kernel forever?

I really like my Dell and my Sony when using the intel_backlight
brightness control and can't stand them with the acpi_video0 control.

Double thanks for Kamal-

[captain toro (commander1oldsmobile)]

Please ignore my comment above. I have just tried the linux 3.1 kernel and found both the acpi_video0 and the intel_backlight in the /sys/class/backlight still available in debian. I thought only the acpi_video was in the 3.0 kernel and so switched to the kamal~mgjbacklight kernel. Maybe I will figure that out after getting this retraction of my previous post done. I am sorry for the previous post I just thought the intel_backlight was replaced by the acpi_video0 in all future kernels. I am very happy now with the intel_backlight control and hope the native brightness controls are retained. Thanks again Kamal-

[cherep (acherep)]

@Kamal
probably I'm only one who stuck in the past with Maverick 10.10 :) but I love it!

After updating to a new kernel, I've lost the brightness control:
$ uname -r
2.6.35-31-generic
$ ls /sys/class/backlight
[empty]

Can you please update the ppa? Do you think the ppa will be maintained in the future for Maverick by 2012-04?
Thanks for your effort!

[Kamal Mostafa (kamalmostafa)]

I have updated my Ubuntu Maverick and Natty kernel PPA's with another new experimental patch by Keith Packard[0]. This new patch may resolve the "inverted brightness" and/or the "jumps with successive changes" behavior that has been reported on some systems:

    https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

The kernels containing the new patch are tagged "~kamal4~..." (use 'uname -a' to check); they will become available within the next day. If you experience any change in your brightness control behavior after updating to this new version, please post a note here.

For Ubuntu Oneiric (11.10), I am maintaining a separate backlight PPA which also now includes this new patch. Oneiric users should see the bug #872652 for that.

[0] http://lists.freedesktop.org/archives/intel-gfx/2011-November/013519.html

[Kamal Mostafa (kamalmostafa)]

@cherep-

I will continue to maintain the linux-kamal-backlight PPA for Maverick and Natty until the 12.04 release, but will likely stop maintaining it after that time. I encourage upgrading to Oneiric; I think it unlikely that the full set of backlight/brightness fixes will ever make it into the official Ubuntu Maverick or Natty kernels at this point.

[valeriop (valerio-passini)]

I want to report my success in finally enabling the brightness control of my LCD screen on
HP Pavilion dv6-6192sl.
I make use of Debian/Sid and a custom 3.1.4 kernel. It didn't worked before until I modified grub and passed the
acpi_backlight=vendor
option to the kernel at boot as told in other posts.
Thank to all that contributed with their experience and to Kamal Mostafa for the patches to Linux.

[rvgsd (rvgsd-id1)]

Hi,

I have a Dell Studio 1558.
uname -a : Linux mypc-Studio-1558 2.6.35-32-generic-pae #67-Ubuntu SMP Mon Mar 5 21:23:19 UTC 2012 i686 GNU/Linux
With no boot parameters
ls /sys/class/backlight: acpi_video0
When using acpi_backlight=vendor as boot parameter:
ls /sys/class/backlight: dell_backlight

Until the latest update i.e. 2.6.35-32, the brightness up/down was working fine with "acpi_backlight=vendor" as the only boot parameter. After the update, the brightness up/down doesn't work and the screen is at full brightness. Note that I have the PAE kernel.

Help! (my eyes are burning and its exam time!!)

Thanks.!

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu laptop testing tracker.

A list of all reports related to this bug can be found here:
http://laptop.qa.ubuntu.com/qatracker/reports/bugs/568611

[cherep (acherep)]

@rvgsd
I think this linux-kamal-backlight PPA is not supported any longer for 10.10 and 11.04.

Kamal suggested to update to 12.04. I've seen backlight controls work fine under 12.04 without any PPA only after adding kernel parameters.

[AlexW (alex.wedensky)]

@cherep
On a Dell Studio 1558 with Intel HD graphics (my hardware) I still have to supply acpi_backlight=vendor to the kernel (both 11.10 and 12.04 beta2) -- but, you are right, no extra PPAs needed.

[Anton Keks (anton-azib)]

More info regarding Toshiba Satellite R830:

I can't change brightness after returning from sleep with Fn-keys, but echoing numbers to /sys/class/backlight/intel_backlight/brightness does change the brightness properly.

It seems that Fn keys write to /sys/class/backlight/acpi_video0/brightness, which doesn't do anything.
Perhaps a fix could be made in Unity (or gnome power manager) to prefer intel_brightness if it's available?

[naveen (naveenmvv)]

i installed ubuntu 12.04 , i cannot change the brightness.
my system is dell 1558.

[naveen (naveenmvv)]

uname -a

Linux ubuntu 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

 ls /sys/class/backlight

acpi_video0 intel_backlight

[Joe Maillard (xxtoocoolxx)]

naveen,

you need to manually set the boot parameter 'acpi_backlight=vendor' if you use grub as your boot manager, edit /boot/grub/grub.cfg and add the parameter to the end of the appropriate line that begins with 'linux'.

be sure to do this whenever you get kernel updates too.

[naveen (naveenmvv)]

Joe Maillard,

i installed using wubi , i cant find boot parameter to edit.

[Luciano Dato (lucianodato)]

I'm on 13.04 beta 2 the problem persist, even adding acpi_backlight=vendor to the boot parameters. I'm on kernel 3.8.0-18 and a12 bios firmware version for my studio 1558

[Luciano Dato (lucianodato)]

Oh I forgot ls /sys/class/backlight dell_backlight intel_backlight and uname -r 3.8.0-18-lowlatency as I've said before

[AlexW (alex.wedensky)]

try the whole string:

acpi_osi=Linux acpi_backlight=vendor dell_laptop.backlight=0

this worked on my Dell Studio 1558 with 3.8 kernels

Alex

On 13-04-17 09:27 PM, Luciano Dato wrote:
> Oh I forgot ls /sys/class/backlight dell_backlight intel_backlight and
> uname -r 3.8.0-18-lowlatency as I've said before
>

[Luciano Dato (lucianodato)]

Thank you Alex that worked with mine too!

[Volkan Gezer (volkangezer)]

Hello,

I am using 3.8.0.26 on Kubuntu 13.04 (KDE) Samsung Laptop and currently using "acpi_osi=Linux acpi_backlight=vendor" to enable backlight control. Whenever I log off, the controls are disabled again and I need to run intel_backlight. Another problem is power profiling. Whatever I set dimming and/or backlight off durations. It automatically turns it off in 5 minutes (even I totally disable it).

 Do you have any idea why the problem is still not solved?