https://bugs.freedesktop.org/show_bug.cgi?id=109178

Jan jv1@home.nl changed:

What |Removed |Added ---------------------------------------------------------------------------- Resolution|NOTOURBUG |FIXED

--- Comment #11 from Jan jv1@home.nl --- Just for the sake of record I found the solution:

The (UEFI based) kernel creates /sys/firmware/efi/efivars with the variable: KBDBacklitLvl-5af56f53-985c-47d5-920c-f1c531d06852

The set immutable flag can be disabled with: chattr -i /sys/firmware/efi/efivars/KBDBacklitLvl-5af56f53-985c-47d5-920c-f1c531d06852

After that the variable can be altered from 00 - 03: echo 0700000002 | xxd -p -r > /sys/firmware/efi/efivars/KBDBacklitLvl-5af56f53-985c-47d5-920c-f1c531d06852 (GUID dependent on the manufacturer)

00 - Backlight off (always) 01 - Backlight on DIM level (by low ambient light; detected by light sensor) 02 - Backlight on NORM level (by low ambient light) 03 - Backlight on FULL level (by low ambient light)

Inspired by: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/1203592