Brightness control keys don't work on Lenovo Y540 but xrandr does

Solution 1:

I have This Issue with Lenovo Y540 that comes with NVIDIA GeForce GTX 1660Ti Graphics Card

Ubuntu version: 19.10

Also, I have upgraded to version 20.04 and working fine

you need to edit or create this file

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

and add this line

Option "RegistryDwords" "EnableBrightnessControl=1;"

after this line Option "AllowEmptyInitialConfiguration"

so the file 10-nvidia.conf will look like this:

Section "OutputClass"
    Identifier "nvidia"
    MatchDriver "nvidia-drm"
    Driver "nvidia"
    Option "AllowEmptyInitialConfiguration"
    Option "RegistryDwords" "EnableBrightnessControl=1;"  # Line need to be added
    ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
EndSection

and save the restart your laptop

and the brightness control keys will work

Solution 2:

Setting the bios to switchable graphics works for me (y540 with gtx1650). Also setting "acpi_backlight=intel_backlight" as kernel option works but also seems to mess with resume from suspend.