I have upgraded to ubuntu 18.04 LTS the display brightness controls are not working. It appears that the brightness is in its lowest level and I am not able to change display brightness at all. It was working on 16.04 LTS. My laptop uses Intel Graphics card.
I have tried to solve that by creating the file /
usr/share/X11/xorg.conf.d/20-intel.conf with the following content. It worked the first time, but after one reboot it remains back to the previous problem.
Section "Device" Identifier "card0" Driver "intel" Option "Backlight" "intel_backlight" BusID "PCI:0:2:0" EndSection
What can I do?