I’m running fedora 32 on a Lenovo p50 and using discrete graphics only. Graphics driver is nouveau.
I see that when the screen turns on again after a blank due to inactivity, the brightness is dimmer than before the blank.
I can see the actual_brightness field reflects this.
To repro:
$ cd /sys/class/backlight/nv_backlight
$ grep . *bright*
actual_brightness:90
brightness:90
max_brightness:100
$ sleep 1; xset dpms force off
# Screen blanks then I press a key to turn it back on
$ grep . *bright*
actual_brightness:37
brightness:90
max_brightness:100
Anyone else observe this behaviour?