Files
systemd/man/systemd-backlight@.service.xml
Lennart Poettering 0c69794138 tree-wide: remove Lennart's copyright lines
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
2018-06-14 10:20:20 +02:00

80 lines
2.6 KiB
XML

<?xml version="1.0"?>
<!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
-->
<refentry id="systemd-backlight@.service" conditional='ENABLE_BACKLIGHT'>
<refentryinfo>
<title>systemd-backlight@.service</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-backlight@.service</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-backlight@.service</refname>
<refname>systemd-backlight</refname>
<refpurpose>Load and save the display backlight brightness at boot and shutdown</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd-backlight@.service</filename></para>
<para><filename>/usr/lib/systemd/systemd-backlight</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><filename>systemd-backlight@.service</filename> 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 <filename>/var/lib/systemd/backlight/</filename>. During
loading, if the udev property <option>ID_BACKLIGHT_CLAMP</option> 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.</para>
</refsect1>
<refsect1>
<title>Kernel Command Line</title>
<para><filename>systemd-backlight</filename> understands the
following kernel command line parameter:</para>
<variablelist class='kernel-commandline-options'>
<varlistentry>
<term><varname>systemd.restore_state=</varname></term>
<listitem><para>Takes a boolean argument. Defaults to
<literal>1</literal>. If <literal>0</literal>, does not
restore the backlight settings on boot. However, settings will
still be stored on shutdown. </para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>