Bug#785460: (no subject)

[Robert Lange <rcl24@drexel.edu>]

When I set the brightness manually, I run the following and see:

$ ls -1 /sys/class/backlight/*/*brightness | xargs -I % sh -c "echo % ;
cat %"

/sys/class/backlight/intel_backlight/actual_brightness
2219
/sys/class/backlight/intel_backlight/brightness
2219
/sys/class/backlight/intel_backlight/max_brightness
4438

However, when I logout and log back in (or reboot) and run the command,
I see:

$ ls -1 /sys/class/backlight/*/*brightness | xargs -I % sh -c "echo % ;
cat %"

/sys/class/backlight/intel_backlight/actual_brightness
4438
/sys/class/backlight/intel_backlight/brightness
4438
/sys/class/backlight/intel_backlight/max_brightness
4438

There is a systemd file which apparently stores the brightness for
restoration during reboot.

$ cat
/var/lib/systemd/backlight/pci-0000\:00\:02.0\:backlight\:intel_backlight
4438

I tried manually editing the file to 2219, but upon logout and login or
reboot, the brightness was still restored to maximum and the file was
restored to 4438.