Brightness control stuck on screen
The conclusion was that the backlight control is handled by the desktop environment.
#BRIGHTNESS CONTROL STUCK ON SCREEN HOW TO#
I don’t know how to do it honestly but I can see that it is not an issue of the kernel.Īlso as another confirmation, when booting in dedicated gpu mode, only the nvidia_0 is present in /sys/class/backlight/ and backlight control works just fine from DE and keyboard keys. So as a fix, I suggest that devs change the target of the backlight change to intel_backlight instead of nvidia’s from the system, then maybe the desktop environment and keyboard mapping will work as intended. I have also checked on my other system running Pop OS and I can confirm that the system applies the changes to the intel_backlight interface and not to the nvidia_0 one when in hybrid mode. So changing manually the values in /sys/class/backlight/intel_backlight/brightness actually changed the brightness level, I think that’s how xrandr and oled-linux probably work. This automatic setting helps make sure your screen is readable wherever you go. Select Brightness, look for the Change brightness automatically when lighting changes check box, and then select it to use this feature. For some reason, changing brightness using fn+F5/fn+F6 or from desktop environment affects the values in the nvidia_0 interface (/sys/class/backlight/nvidia_0/actual_brightness so the changes are not visible since technically it is intel gpu that outputs at the end in hybrid mode. To find out if your PC supports this, select Settings > System > Display.
In all cases, the tiles move appropriately, but there is no actual change in brightness. If you turn on the machine in hybrid mode, you will find both of these. I updated to Big Sur last night (Nov 15th), and I am unable to adjust the screen brightness using either the function keys, command center, or system preferences. One for intel intel_backlight and the other for nvidia nvidia_0. So after some tinkering, I found that for this model, there are two backlight interfaces located in /sys/class/backlight/. Here are my findings that I mentioned in the archlinux forum: