Nvidia Brightness problem Ubuntu 18.04

The brightness control in Ubuntu 18.04 does not have any effect on the screen brightness on my Asus TUF A15. I have tried everything suggested here: Brightness problem Ubuntu

I have added to /usr/share/X11/xorg.conf.d/10-nvidia.conf as this:

Section "OutputClass"
   Identifier "nvidia"
   MatchDriver "nvidia-drm"
   Driver "nvidia"
   Option "AllowEmptyInitialConfiguration"
   ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
   Option "Backlight" "acpi_video0"
EndSection

And changed the relevant line in /etc/default/grub to read:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=video"

I've run apt update-grub and rebooted. I've tried nvidia-drivers-330 and 340. All to no effect.

Anything else I can try? Is my 10-nvidia.conf file correct?

Solution 1:

Upgrading to kernel 5.9 sorted this problem out, as older kernels are not able to deal with AMD CPUs and Nvidia graphs cards together, apparently.