I recently got a Lenovo ThinkPad T495 where I dualboot Ubuntu 18.04.

Unfortunately I cant adjust the screen brightness.

I have already tried with this solution (Brightness problem Ubuntu 18.04 LTS), but with no luck.

The acpi_backlight=video option seems to be closer to solution for me, in the sense that at least the brightness bar goes up and down properly when applying this fix (only the bar changes not the actual brightness!). But I guess my configuration file should look a bit different from the one provided in the link.

When I run

sudo lshw -c video | grep 'configuration'

to find out my graphic drivers I only get this answer:

configuration: latency=0

1 Answer 1


For the Thinkpad T495, you should use acpi_backlight=vendor, afterwards you can change your brightness with echo 150 > /sys/class/backlight/amdgpu_bl0/brightness.

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