Screen brightness control not working on Lenovo T530

Question

My brightness control doesn't work with a fresh install of 12.10 (brand new laptop). It is set to the brightest setting when I boot up and when I try to change it, I see the notification bar come up but the brightness doesn't actually change. I've tried all the solutions I could find around the Internet but none of them work. Things I have tried include:

Editing /sys/class/backlight/acpi_video0/brightness

In /usr/share/X11/xorg.conf.d/10-brightness-control.conf: Option "RegistryDwords" "EnableBrightnessControl=1"

In /etc/default/grub: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"

There is no xorg.conf file in 12.10 that I have found, so the solutions that suggest editing that file don't do me a whole lot of good.

I am currently using the Nouveau driver, but switching to the Nvidia proprietary drivers made no difference.

Any other ideas? When is this bug going to be fixed? With all the reports I've come across I would think it would get a lot of attention. Thanks.

Solution 1

I had a similar problem on my thinkpad W530. I finally found a solution here:

http://blog.pearce.org.nz/2012/08/enabling-external-monitor-on-lenovo.html

These days X automatically configures itself, so you can't just edit the xorg.conf file, you instead need to add a section to a file in /usr/share/X11/xorg.conf.d/ and X will include that section in the configuration that it automatically generates.

So to get the screen brightness keys working with your Nvidia graphics card, create a file in the xorg.conf.d directory, e.g:

sudo gedit /usr/share/X11/xorg.conf.d/10-nvidia-brightness.conf

Paste the following into the file:

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "Quadro K1000M"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
EndSection

Solution 2

Did Ubuntu backported patches from Kernel 3.7 to 3.6? That could be the cause, see here: https://bugzilla.kernel.org/show_bug.cgi?id=51231

Try to use the brightness slider vom "System Settings" > "Brightness & Lock" in GNOME.

Comments

[Matt]

Thanks for pointing me to the diagnostics page, but none of the ideas there worked either. I filed a bug on Launchpad as per the instructions there. Any other suggestions?

[Web-E]

See the updated answer

[Matt]

[ 2.544835] thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver [ 2.544838] thinkpad_acpi: Disabling thinkpad-acpi brightness events by default... [ 2.549966] thinkpad_acpi: Standard ACPI backlight interface available, not loading native one [ 2.589309] ACPI Warning: 0x0000000000000460-0x000000000000047f SystemIO conflicts with Region _SB_.PCI0.LPC_.PMIO 1 (20120320/utaddress-251) [ 2.589323] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver

[Matt]

Tried the slider, no change.

[ben author]

+100... i've been switching to a virtual console to use my brightness controls for an embarrassing amount of time

[patryk.beza]

Here you can find really nice summary of the same problem.

[axolotl]

I have an AMD powered graphics card on my ThinkPad E460. What do I need to change in this file?