man > systemd-backlight@.service(8)

SYSTEMD-BACKLIGHT@.SERVICE(8)        systemd-backlight@.service        SYSTEMD-BACKLIGHT@.SERVICE(8)

NAME
       systemd-backlight@.service, systemd-backlight - Load and save the display backlight
       brightness at boot and shutdown

SYNOPSIS
       systemd-backlight@.service

       /usr/lib/systemd/systemd-backlight save [backlight|leds]:DEVICE

       /usr/lib/systemd/systemd-backlight load [backlight|leds]:DEVICE

DESCRIPTION
       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 in
       /var/lib/systemd/backlight/. During loading, if the udev property ID_BACKLIGHT_CLAMP is not
       set to false, the brightness is clamped to a value of at least 1 or 5% of maximum brightness,
       whichever is greater. The percentage can be adjusted by specifying a percentage (needs to be
       suffixed with "%", e.g.  "30%") to the property ID_BACKLIGHT_CLAMP.

KERNEL COMMAND LINE
       systemd-backlight understands the following kernel command line parameter:

       systemd.restore_state=
           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.

           Added in version 209.

SEE ALSO
       systemd(1)

systemd 255                                                            SYSTEMD-BACKLIGHT@.SERVICE(8)