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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-12 03:50:40 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-12 03:50:40 +0000
commitfc53809803cd2bc2434e312b19a18fa36776da12 (patch)
treeb4b43bd6538f51965ce32856e9c053d0f90919c8 /man/systemd-backlight@.service.xml
parentAdding upstream version 255.5. (diff)
downloadsystemd-fc53809803cd2bc2434e312b19a18fa36776da12.tar.xz
systemd-fc53809803cd2bc2434e312b19a18fa36776da12.zip
Adding upstream version 256.upstream/256
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/systemd-backlight@.service.xml')
-rw-r--r--man/systemd-backlight@.service.xml27
1 files changed, 18 insertions, 9 deletions
diff --git a/man/systemd-backlight@.service.xml b/man/systemd-backlight@.service.xml
index 431b27b..bb7f2b6 100644
--- a/man/systemd-backlight@.service.xml
+++ b/man/systemd-backlight@.service.xml
@@ -1,9 +1,9 @@
<?xml version="1.0"?>
<!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
- "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
-<refentry id="systemd-backlight@.service" conditional='ENABLE_BACKLIGHT'
+<refentry id="systemd-backlight_.service" conditional='ENABLE_BACKLIGHT'
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
@@ -31,13 +31,22 @@
<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. The percentage can be adjusted by specifying a
- percentage (needs to be suffixed with <literal>%</literal>, e.g. <literal>30%</literal>) to the property
- <option>ID_BACKLIGHT_CLAMP</option>.</para>
+ <para><filename>systemd-backlight@.service</filename> is a service that restores the brightness of
+ a display backlight or LED (e.g. keyboard backlight) device at early boot, and saves it at shutdown.
+ The brightness is stored in <filename>/var/lib/systemd/backlight/</filename>.</para>
+
+ <para>On restoring brightness of a display backlight device, <command>systemd-backlight</command> reads
+ <varname>ID_BACKLIGHT_CLAMP</varname> udev property, that takes a boolean value or a percentage (needs to
+ be suffixed with <literal>%</literal>, e.g. <literal>30%</literal>). When a percentage is specified, the
+ saved brightness is clamped to a value of at least 1 or the specified percentage of the maximum
+ brightness, whichever is greater. When unset or set to true, the brightness is clamped in the same way
+ with percentage 5%. When false, the saved brightness will not be clamped, and loaded as is.</para>
+
+ <para>On restoring brightness of a LED device, <command>systemd-backlight</command> reads
+ <varname>ID_LEDS_CLAMP</varname> udev property, that also takes a boolean value or a percentage. When a
+ percentage is specified, the saved brightness is clamped to the specified percentage of the maximum
+ brightness. When set to true, the brightness is clamped in the same way with percentage 5%. When unset or
+ set to false, the saved brightness will not be clamped, and loaded as is.</para>
</refsect1>
<refsect1>