I experienced the following problem when trying to change brightness either through the system settings of the shell, or by using fn + f2 fn+f3 combinations. The brightness bar appears in the top left corner of the screen and the whole system becomes non-responsive. Trying to change the brightness with
xrandr works without problems, though. The laptop uses an Nvidia optimus card. The problem appears both with the
nvidia-current driver installed and without it.
Is there any way to disable what causes this failure?
Thank you for your help it almost works now. I can reduce the brightness with the buttons and through the shell, though I can't increase it back. In this path
/sys/class/backlight i have two similar directories. One called
Samsung and one called
intel_backlight. If I try to modify the values in the Samsung I cannot get more than 3 out of 8. However if I modify the
intel_backlight I can increase back to max.