'\" t .TH "SYSTEMD\-BACKLIGHT@\&.SERVICE" "8" "" "systemd 241" "systemd-backlight@.service" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" systemd-backlight@.service, systemd-backlight \- Load and save the display backlight brightness at boot and shutdown .SH "SYNOPSIS" .PP systemd\-backlight@\&.service .PP /lib/systemd/systemd\-backlight .SH "DESCRIPTION" .PP 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 \fBID_BACKLIGHT_CLAMP\fR is 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 display\&. .SH "KERNEL COMMAND LINE" .PP systemd\-backlight understands the following kernel command line parameter: .PP \fIsystemd\&.restore_state=\fR .RS 4 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\&. .RE .SH "SEE ALSO" .PP \fBsystemd\fR(1)