2

My Fn+F8 and Fn+F9 keys to change the screen's brightness appear to no longer work on my Thinkpad laptop.

# ls /sys/class/backlight/
thinkpad_screen

Some guide told me to make this:

# cat /usr/share/X11/xorg.conf.d/20-intel.conf 
Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"
EndSection

And someone else said to do this:

# cat /usr/share/X11/xorg.conf.d/20-nvidia.conf 
Section "Device"
        Identifier "NVIDIA"
        Driver "nvidia"
        Option "NoLogo" "True"
        Option "RegistryDwords" "EnableBrightnessControl=1"
EndSection

This is my GRUB CMDLINE_LINUX_DEFAULT line, in case it's relevant: GRUB_CMDLINE_LINUX_DEFAULT="nosplash nomodeset acpi_osi=Linux acpi_backlight=vendor"

The Ubuntu wiki page on backlight issues says

Add just kernel parameters thinkpad-acpi.brightness_enable=1 acpi_backlight=vendor to /boot/grub/menu.lst . Execute: sudo update grub

but I don't have a menu.lst and I suspect this is outdated.

Doing something like this does not work: echo 10 > /sys/class/backlight/thinkpad_screen/brightness

Any ideas?

Espressofa
  • 393

3 Answers3

1

Removing all kernel boot parameters and installing the ppa:xorg-edgers/ppa's nvidia drivers fixed the issue.

Espressofa
  • 393
0

I found that changing my GRUB CMDLINE_LINUX_DEFAULT line to the following works on my Lenovo y510p:

GRUB_CMDLINE_LINUX_DEFAULT="nosplash quiet acpi_backlight=intel_backlight"

To accomplish this, run this command:

sudo gedit /etc/default/grub

Make the edit, save / exit gedit. Then run the command:

sudo update-grub

Now all you need to do is restart by typing the following command and back lights should work.

sudo reboot

Now the "Fn + up arrow" or "Fn + down arrow" works to brighten or dim the display

hmayag
  • 2,266
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JimsJump
  • 1
0

Creating this file solved the problem for nvidia nvs5400m in a Thinkpad T530. Thank you.

cat /usr/share/X11/xorg.conf.d/20-nvidia.conf 


Section "Device"
        Identifier "NVIDIA"
        Driver "nvidia"
        Option "NoLogo" "True"
        Option "RegistryDwords" "EnableBrightnessControl=1"
EndSection
hg8
  • 13,582
John Z Ice
  • 1