1002:983d [Acer Aspire V5-122P] Unable to adjust screen brightness using Radeon driver

[Lewis Toohey]

While using the Radeon driver, I am unable to adjust the screen brightness on my Acer Aspire V5-122P. Adjusting brightness in the settings applet has no affect. Adjusting brightness with the keyboard function keys turns the screen on and off seemingly randomly.

WORKAROUND: sudo -s
cd /sys/class/backlight/radeon_bl0
cat max_brightness
echo 200 > brightness #Example
echo 10 > brightness #Example
echo 255 > brightness #Example

Upstream post URL: http://www.spinics.net/lists/linux-acpi/msg50719.html

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-24-generic 3.13.0-24.46
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: lewis 2240 F.... pulseaudio
 /dev/snd/controlC0: lewis 2240 F.... pulseaudio
CurrentDesktop: Unity
Date: Sun May 4 10:55:50 2014
HibernationDevice: RESUME=UUID=42931b07-a2e1-49a1-9780-874e1d4300b7
InstallationDate: Installed on 2014-04-14 (19 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326)
MachineType: Acer Aspire V5-122P
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic.efi.signed root=UUID=8a594eb2-ccc3-4aa4-a4c5-e872f4033b04 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-24-generic N/A
 linux-backports-modules-3.13.0-24-generic N/A
 linux-firmware 1.127
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/18/2013
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: V2.08
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Aspire V5-122P
dmi.board.vendor: Acer
dmi.board.version: V2.08
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V2.08
dmi.modalias: dmi:bvnInsydeCorp.:bvrV2.08:bd07/18/2013:svnAcer:pnAspireV5-122P:pvrV2.08:rvnAcer:rnAspireV5-122P:rvrV2.08:cvnAcer:ct10:cvrV2.08:
dmi.product.name: Aspire V5-122P
dmi.product.version: V2.08
dmi.sys.vendor: Acer

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.15 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-rc4-utopic/

[Lewis Toohey (lewis-x)]

Joseph

Many thanks for your response. I have installed and tested the bug against the kernel installed by package:

linux-image-3.15.0-031500rc4-generic_3.15.0-031500rc4.201405042135_amd64.deb

The problem remains identical to the standard Ubuntu kernel (as described in my initial report).

I believe that I have added the tag "kernel-bug-exists-upstream" as requested.

Many thanks

[Lewis Toohey (lewis-x)]

Chris

I can confirm that the bug exists after having updated my bios (2.08 -> 2.10). I have also checked the new bios with the upstream kernel for completeness.

The problem remains identical to the description given in my initial report. I have removed the outdated bios tag and set this back to confirmed (which I hope is the correct procedure).

Output from the commands you requested:

$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
[sudo] password for lewis:
V2.10
10/14/2013

[penalvch (penalvch)]

Lewis Toohey, could you please test the latest mainline kernel via http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-rc5-utopic/ and advise to the results?

[Lewis Toohey (lewis-x)]

Chris

I can confirm that the bug is still present after loading the kernel installed by package:

linux-image-3.15.0-031500rc5-generic_3.15.0-031500rc5.201405091635_amd64.deb

The problem remains identical to the standard Ubuntu kernel (as described in my initial report). I have not altered the tags on my report this time as I am unsure of the procedure here.

Many thanks

[penalvch (penalvch)]

Lewis Toohey, does the proprietary drivers provide a WORKAROUND following https://help.ubuntu.com/community/BinaryDriverHowto/AMD ?

[Will Chester (william-chester)]

Lewis and Chris,

I can confirm that I am experiencing the same behavior as Lewis. I have used both the open source radeon/ati drivers as well as the proprietary fglrx drivers (I'm currently using the fglrx-updates package (2:13.350.1-0ubuntu2) from the Ubuntu repos). I have not yet tried the 14.4 version of fglrx, but can verify that the issue is still present with the proprietary drivers installed.

I'm not sure if this is relevant or not, but when the laptop is unplugged it looks as if the contrast is reduced in line with a decrease in backlight, but the brightness is not similarly reduced. For example, everything looks washed out and there is very little contrast. If you then play with the brightness hotkeys and are able to reduce the backlight to it's lowest settings (reducing the brightness), the contrast/brightness balance is back to normal (at the lowest brightness setting). These are the only two brightness levels that I can get working - full brightness and lowest brightness.

I was able to use a workaround detailed here: http://ati.cchtml.com/show_bug.cgi?id=711#c54 to get appropriate contrast/brightness balance on battery at the highest brightness level, but I am still unable to change the backlight settings beyond lowest or highest brightness.

Hope that helps. Thank you for looking into this.

[Lewis Toohey (lewis-x)]

Chris

For completeness, I can confirm what Chris has said (i.e. the fglrx drivers do not solve the problem). My testing shows almost the same situation as Chris has kindly noted. By way of a summary:

3.15rc5 kernel with fglrx drivers - X won't start
3.13 kernel with fglrx drivers on AC power - exactly the same bug as my original report (screen alternates between full brightness and black)
3.13 kernel with fglrx drivers on battery power - almost the same problem except screen alternates between full brightness and what looks like around 5% brightness.

In summary the fglrx drivers do not appear to provide a work around.

I hope that helps

[penalvch (penalvch)]

Will Chester, thank you for your comment. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[penalvch (penalvch)]

Lewis Toohey, the issue you are reporting is an upstream one. Could you please report this problem through the appropriate channel by following the instructions _verbatim_ at https://wiki.ubuntu.com/Bugs/Upstream/kernel ?

Please provide a direct URL to your e-mail to the mailing list once you have made it so that it may be tracked.

Thank you for your understanding.

[Lewis Toohey (lewis-x)]

Chris

I have prepared my email with the information requested as advised in the link you provided (see attached).

I have determined that I should sent it to <email address hidden> (being listed as "for discussions on ati driver related issues." under "graphics issues"). Before I send it, please can you confirm that this is the correct choice based on the nature of this bug? Is this a "graphics issue" for these purposes?

In addition, I am unsure what you mean by "please provide a direct URL to your e-mail to the mailing list once you have made it". I can (obviously) send an email in plain text, but I don't know of an easy way to make such sent email available via a URL (though I could possible host something myself). Can you advise what you meant here?

Many thanks

[penalvch (penalvch)]

Lewis Toohey, the contents look good. You may want to start with the linux-acpi mailinglist, as brightness problems tend to be addressed there.

[Lewis Toohey (lewis-x)]

Chris - thanks. I have submitted the report today in the format I previously attached to the acpi mailing list. I will revert if and when I hear back.

Many thanks

[Lewis Toohey (lewis-x)]

No "fix" yet as such, however, thanks to kernel developer AAron Lu I can confirm that there is a workaround to manually adjust screen brightness.

Its not overly practical, but you possibly write a script to do it. The sequence of commands is below. Essentially it involves accessing your video card via /sys and poking the brightness value directly. Mine video is detected as radeon_bl0.

I will revert when I have further information.

lewis@HappyFunMeaowMeaow:~$ sudo -s
[sudo] password for lewis:
root@HappyFunMeaowMeaow:~# cd /sys/class/backlight/radeon_bl0
root@HappyFunMeaowMeaow:/sys/class/backlight/radeon_bl0# cat max_brightness
255 #Max value for your hardware
root@HappyFunMeaowMeaow:/sys/class/backlight/radeon_bl0# echo 200 > brightness #Example
root@HappyFunMeaowMeaow:/sys/class/backlight/radeon_bl0# echo 10 > brightness #Example
root@HappyFunMeaowMeaow:/sys/class/backlight/radeon_bl0# echo 255 > brightness #Example
root@HappyFunMeaowMeaow:/sys/class/backlight/radeon_bl0#

[Will Chester (william-chester)]

Chris,

Apologies for the delay submitting the bug report. I have now submitted a new bug at the following location and have subscribed you:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1322004

Let me know what else I can do to help with this.

Additionally, Lewis, the workaround you put forth doesn't work for me. I don't have a radeon_bl0 entry in my /sys/class/backlight/acpi_video0/ folder. This may be because I'm using the fglrx driver and it looks like you're currently using the radeon driver.

Thanks,

Will

[Lewis Toohey (lewis-x)]

Will

I am indeed using the Radeon driver, however, for clarity, you are not looking inside the acpi_video0 directory for the other entries but rather its parent directory. Also it might not be called radeon_bl0 on your system.

Essentially if you list your /sys/class/backlight directory you will (probably) have multiple entries (one of which is acpi_video0). For example, I have two: acpi_video0 and radeon_bl0. You may have different entries, especially if you are using the fglrx driver.

You need to go into each of these entries/directories one by one and try to adjust the brightness as described in my original post. Hopefully one of them will work.

From my (very limited) understanding, I think that this is the essence of the bug (i.e. the acpi_video0 interface device is not properly "hooked up" to the actual display adapter).

Having said that, what do I know?!

Many thanks

[Lewis Toohey (lewis-x)]

I have been asked to test a kernel patch for this bug but I am struggling to do so.

I am able to obtain the source to the most recent Ubuntu kernel and compile it. The patch, however, appears to have been written for a later kernel version. The 3.13 kernel will not compile after applying it. I believe I need at least 3.14, maybe 3.15.

I am aware of the mainline kernel repository that contains kernels pre-built upstream kernels for ubuntu. No source is provided.

I need a way to either:
1) get hold of the source for these mainline packages in the same way I can get the source for the most recent ubuntu kernel; or
2) figure out how to compile the "pure" kernel source from kernel.org for Ubuntu.

Can anyone advise before I go back to the kernel devs?

[penalvch (penalvch)]

Lewis Toohey, you would want to review https://wiki.ubuntu.com/Kernel/KernelBisection#Testing_a_newly_released_patch_from_upstream in order to apply a patch.

[dastillero (dastillero)]

I upgraded BIOS to the last available versión (2.12) and brightness control seems to work now using Ubuntu 14.04.1 x64 live media and Radeon driver.

[Lewis Toohey (lewis-x)]

Confirmed - upgrading to the latest bios (2.12) fixes both the brightness issue and fixes the suspend and resume problem present in later kernels.

Looks like this can be put to bed.

[Mark - Syminet (mark-syminet)]

Also Confirmed - vendor issue, not Ubuntu - BIOS upgrade fixed brightness / suspend issues as well for me. Everything now works flawlessly.

A bit OT but in case others arrive here via google: the V5-122P BIOS updates *require* you to be running Windows 8 or newer. If you aren't dual booting into Windows, Acer forcing a Windows 8 binary in order to update the BIOS makes for a *very* bad day. FreeDOS does not work, not even WindowsPE on 32-bit works - it has to be Windows 8.

Note being, when looking to buy hardware in the future not only will be googling linux compatability, but also checking to make sure the vendor is releasing BIOS patches which are easily installed using Linux as well.

[penalvch (penalvch)]

Not Status Fix Released as defined in https://wiki.ubuntu.com/Bugs/Status .