systemd-backlight@.service, systemd-backlight — Load and save the display backlight brightness at boot and shutdown
systemd-backlight@.service is a service
that restores the display backlight brightness at early boot and
saves it at shutdown. On disk, the backlight brightness is stored
loading, if the udev property
not set to false, the brightness is clamped to a value of at
least 1 or 5% of maximum brightness, whichever is greater. This
restriction will be removed when the kernel allows user space to
reliably set a brightness value which does not turn off the
systemd-backlight understands the
following kernel command line parameter:
Takes a boolean argument. Defaults to
1". If "
0", does not
restore the backlight settings on boot. However, settings will
still be stored on shutdown.