laptop screen blacklight brightness always at 100% (even on battery), can't be lowered

[Mathieu Pellerin]

Since I upgraded to Ubuntu natty, I can't change the screen's backlight brightness. This is a huge regression from maverick (under which I could change the brightness). It appears to have something to do with the new nvidia drivers under natty.

The problem persists even when the laptop is running on battery. Due to this, the battery gets empty after running for only 1h15min.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: nvidia-current 270.41.03-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
NonfreeKernelModules: wl nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86 Kernel Module 270.41.03 Sat Apr 9 00:04:57 PDT 2011
 GCC version: gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu3)
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,gnomecompat,resize,imgpng,mousepoll,move,vpswitch,regex,place,wall,grid,snap,session,animation,expo,workarounds,ezoom,staticswitcher,fade,scale,unityshell]
CompositorRunning: compiz
Date: Mon Apr 18 10:37:39 2011
DistUpgraded: Fresh install
DistroCodename: natty
DistroVariant: ubuntu
GraphicsCard:
 nVidia Corporation GT216 [GeForce GT 330M] [10de:0a29] (rev a2) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:0442]
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
JockeyStatus:
 kmod:wl - Broadcom STA wireless driver (Proprietary, Enabled, In use) [auto-install]
 xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
MachineType: Dell Inc. Vostro 3700
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=1317ee43-70a2-489f-9bf0-540fdfc75cea ro quiet splash vt.handoff=7
Renderer: Unknown
SourcePackage: nvidia-graphics-drivers
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/25/2010
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: 0R6NH5
dmi.board.vendor: Dell Inc.
dmi.board.version: A10
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A10
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd10/25/2010:svnDellInc.:pnVostro3700:pvrA10:rvnDellInc.:rn0R6NH5:rvrA10:cvnDellInc.:ct8:cvrA10:
dmi.product.name: Vostro 3700
dmi.product.version: A10
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.4+bzr20110415-0ubuntu1
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu1
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7

[K. O. (h-admin-mi-fh-offenburg-de)]

Same problem here!

I have tried that xorg.conf-Fix (Option "RegistryDwords" "EnableBrightnessControl=1") but no change. Without the nvidia-drivers (Package nvidia-current and -settings) brightness works again ([FN] + [Up] or [Down])

As this is a major problem i hope for a quick solution/fix.

Thanks,
K.O.

[Piotr Pędziwiatr (szybki)]

same here - since i've updated to 11.04, i can't change brightness with Fn + Up/Down (dell vostro 3700 with nvidia gt330)

please fix this..

thanks,
P.P.

[Piotr Pędziwiatr (szybki)]

http://askubuntu.com/questions/21523/screen-brightness-not-changing-on-acer-5742-notebook
this solution worked for me.

[Mathieu Pellerin (nirvn-asia)]

The link mentioned in comment 4 also worked out for me. Thanks Piotr.

[K. O. (h-admin-mi-fh-offenburg-de)]

The mentioned solutions doesn't work for me. Still no reaction when pressing FN + Up/Down nor any other posibility to change brightness.

Have you guys done any further things beside these 3 steps (change grub-file, update-grub and reboot)?

BTW, my System is an Samsung P55 Pro Bengy (T7500, Nvidia GS8600M)

Please, i appreciate any help!

[gabrys (piotr-ubuntubugs)]

I had a similar problem. GRUB configuration change didn't work. Adding stuff to xorg.conf neither. But I managed to "fix" it using a Python program that binds to D-Bus signal BrightnessChanged and sets the proper brightness using nvclock command. Check this out at my blog: http://piotr.gabryjeluk.pl/dev:ubuntu-11-04-natty-on-sony-vaio-sz640

[bro (matthijsbro)]

I just received the W520 lenovo with quadro 1000m from nvidia and installed ubuntu 11.04.

 I cannot change the screen brightness. What's worse: If I try with the Fn shortcuts my screen freezes and I need a hard reboot (!).
Bios has graphics set to discrete only.

[bro (matthijsbro)]

Unfortunately none of the above worked for me. I have been able to use the intel drivers for integrate graphics only by using the script from comment #7 http://piotr.gabryjeluk.pl/dev:ubuntu-11-04-natty-on-sony-vaio-sz640

This was necessary because nvidia drivers presence apparently breaks the 3d support from the intel.

Also, when using the nvidia card I the 'additional drivers' kept insisting that the nvidia driver was installed, but not in use. I thought I might be using nouveau by accident, but I've removed it and still it was denying the use of the proprietary driver (though compiz support was there)

[laurybueno (laury-bueno)]

Guys, the best thing i could manage until now was install the ¨experimental¨ drivers for nvidia.

When I open the ¨additional drivers¨, he gives me two options, the proprietary and the open source.

Using the proprietary, I can´t control the backlight (stays at 100%), but i can use unity. By the way, in this situation, the ¨additional drivers¨ dialog says the nvidia driver is installed but not ¨currently in use¨, just like bro described.

Using the open source ¨experimental¨ alternative, the backlight control works the same way than worked with no special driver installed at all. In that situation, I can´t use unity, but I can control brightness.

One thing worth saying is that even when I can control the backlight (with nvidia open source, or with no special driver), this control is strange. I only have four degrees of light and I can vary among them with the four lower degrees of the graphic indicator. All the higher levels are useless.

I´m using the nVidia Corporation GT218 [GeForce 310M] (rev a2) on a Sony Vaio VPCCW21FX.

[laurybueno (laury-bueno)]

People, I finally found a real workaround.

using the official nvidia driver, I installed the package nvidia-bl-dkms from the Mactel PPA (https://launchpad.net/~mactel-support/+archive/ppa)

Now I can control the backlight perfectly. Not even with the noveau driver I could control it with this much precision.

Just to remember, I´m using the nVidia Corporation GT218 [GeForce 310M] (rev a2) on a Sony Vaio VPCCW21FX.

[juseh (victor0110)]

@laurybueno's solution works here.
Same model, a Sony Vaio VPCCW21FX with GeForce 310M

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Tom Gelinas (tomgelinas)]

The nvidiabl driver now detects ThinkPad T510s with model 4313CTO. This will not allow gnome-power-manager to control the backlight, but at least the keys will work....sort of. With autodetected values, brightness can be turned down all the way, but can only be set to a proper maximum by switching to a VT and turning the brightness down a notch. If anyone would like to play around with backlight values, the instructions below will get them set up. nvidiabl's source can be modified to work with other ThinkPad models as well.

ACPI backlight control must be set to vendor, the thinkpad_acpi module's brightness controls must be disabled and the brightness keys must be bound using acpi events.

ACPI backlight controls can be set to vendor by setting 'GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor"' in /etc/default/grub and then running update-grub.

thinkpad_acpi's brightness controls can be disabled by creating /etc/modprobe.d/thinkpad_acpi.conf and adding the line "options thinkpad_acpi brightness_enable=0".

nvidiabl source can be obtained from https://github.com/guillaumezin/nvidiabl , then installed by dkms. The scripts "nvidia_backlight_down.sh" and "nvidia_backlight_up.sh" should be copied from the scripts folder to /etc/acpi.

Then the brightness keys can be bound to those scripts by creating/filling the following files:

/etc/acpi/events/lenovo-4313cto-brightness-down
event=video LCD0 00000087 00000000
action=/etc/acpi/nvidia_backlight_down.sh

/etc/acpi/events/lenovo-4313cto-brightness-up
event=video LCD0 00000086 00000000
action=/etc/acpi/nvidia_backlight_up.sh

ACPI events were determined using acpi_listen.

[Tom Gelinas (tomgelinas)]

And alternately, there are .deb packages that install nvidiabl via dkms available from https://github.com/guillaumezin/nvidiabl/downloads . Currently only 4313CTO models have backlight support by default, but it's only a matter of adding PCI IDs and some basic detection stuff. That stuff can be passed when the module is loaded, check the docs for details.

[Bryce Harrington (bryce)]

Hey nirvn-asia,

You filed this bug report against natty, but I see it's still open and
doesn't appear to have much activity recently. So, now that oneiric
is released and stable, this may be a good point for you to upgrade
and re-test if this issue is still present there.

If it's solved in the new release and you think it's worth backporting
the fix, please indicate that. Or if having the fix in the new release
is good enough, feel free to close out the bug (or let us know and we'll
close it.)

If it's not solved, leave the bug report open. I can't promise we'll
get to it (we get way more bugs filed than we can usually get to), but
your testing and feedback can help out if and when we do.

[Andrew Gunnerson (cxl)]

This bug still exists in Ubuntu 11.10 and will continue to exist in future Ubuntu versions because, as far as I know, this is a bug in the nVidia blob that only nVidia can fix.

[Scott Lanham (scott-mail)]

I have an Asus G55VW and backlight hotkeys do not work and neither does trying to directly manipulate /sys/class/backlight ... I have tried adding "Option "RegistryDwords" "EnableBrightnessControl=1"" and changing the kernel boot params but with no success.

[dino99 (9d9)]

That version is no more supported; please open a new bug report if the actual archive found version also has the same issue.