Lenovo Thinkpad X1 Extreme Gen 3 Unable to Adjust Backlight after Upgrading to Linux 5.10

Hello everyone,

Today I saw a message suggesting to update to 5.10 kernel, and I happily did it, but now I cannot adjust my laptop’s screen backlight.

On Linux 5.9, I adjust the backlight by writing to the file /sys/class/backlight/nvidia_0/brightness, and if I look at the nvidia_0 directory, it’s a symlink to another directory:

lrwxrwxrwx root root 0 B 5 minutes ago nvidia_0 ⇒ ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/nvidia_0

But when I boot using 5.10, my /sys/class/backlight directory is empty.

On Linux 5.9, I have the following when I search for backlight in /sys/devices:

pci0000:00/0000:00:01.0/0000:01:00.0/backlight
platform/thinkpad_acpi/leds/tpacpi::kbd_backlight

But on Linux 5.10, I only have this:

platform/thinkpad_acpi/leds/tpacpi::kbd_backlight

I get this when I do mhwd -li:

Warning: config '/var/lib/mhwd/local/pci/video-nvidia-455xx/MHWDCONFIG' is invalid!
> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
          video-nvidia            2020.11.30               false            PCI


Warning: No installed USB configs!

I’m not sure what the warning is about, but on 5.9, I also get the warning, and the backlight works

That means there is something wrong with your driver install, it might be related…
Try to fully uninstall the driver using mhwd and then re-install it.

PS: I added the #kernel tag so it will be better spotted by people watching that tag only…

Thank you @TriMoon, I’ll give that a shot

thank you :slightly_smiling_face:

I tried that, and it didn’t work

I guess nobody knows how to solve this problem :slightly_frowning_face:

Give it time, maybe in near future someone with enough knowledge will notice this topic :wink:
We can know a lot,but not everything, and no-one is online on the forum 24/7 that knows how to solve every problem :wink:

Totally agree @TriMoon, but from past experience, if I don’t get an answer in the first 1 or 2 days, I won’t get it ever!

I really hope what you said happens because it’s basically blocking me from going to 5.10 :disappointed:

I just remembered a topic relating to backlight that you might want to check out:

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I have the same issue on a Dell XPS 15 with OLED screen. Brightness is adjustable on 5.9 (I believe because of some patches that were cherrypicked in the Manjaro kernel), but it broke in 5.10.

@janlugt there are new patches available as of 2020-12-04. @schinfo @philm maybe you could incorporate those into the Manjaro kernel builds if you deem them appropriate?

The patches doesn’t work - build is broken if they are included.

They will be included by default in 5.12, till then use icc-brightness-gnome-git