systemd-backlight@.servicesystemdDeveloperLennartPoetteringlennart@poettering.netsystemd-backlight@.service8systemd-backlight@.servicesystemd-backlightLoad and save the display backlight brightness at boot and shutdownsystemd-backlight@.service/usr/lib/systemd/systemd-backlightDescriptionsystemd-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 udev property is
not set to false value, 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
display.Kernel Command Linesystemd-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. See Alsosystemd1