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:
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…
Give it time, maybe in near future someone with enough knowledge will notice this topic
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
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. @nightmare-2021@philm maybe you could incorporate those into the Manjaro kernel builds if you deem them appropriate?