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.IX Title "sysfs.conf 5"
.TH sysfs.conf 5 2024-01-10 2.1.1-6 sysfsutils
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.SH NAME
sysfs.conf, sysfs.d/*.conf \- Linux sysfs attributes setting configuration files
.SH DESCRIPTION
.IX Header "DESCRIPTION"
These configuration files are used to set \fBsysfs\fR attribute values and
modify their file mode or owner, during the system boot.
.PP
Note that these configuration files are concerned with the \fI/sys\fR filesystem
and should not be confused with the \fI/etc/sysctl.conf\fR configuration which
is concerned with the \fI/proc/sys\fR filesystem instead.
.SH FORMAT
.IX Header "FORMAT"
The syntax consists on a series of line based directives for \fIsysfs\fR
attributes, those being pathnames within that filesystem, with the
following format:
.IP "\fIattribute\fR = \fIvalue\fR" 4
.IX Item "attribute = value"
Set \fIvalue\fR for the \fIsysfs\fR \fIattribute\fR.
.IP "\fBmode\fR \fIattribute\fR = \fImode\fR" 4
.IX Item "mode attribute = mode"
Set the \fImode\fR for the \fIsysfs\fR \fIattribute\fR.
Where \fImode\fR is any mode accepted by \fBchmod\fR\|(1).
.IP "\fBowner\fR \fIattribute\fR = \fIowner\fR[:\fIgroup\fR]" 4
.IX Item "owner attribute = owner[:group]"
Set the \fIowner\fR (and/or \fIgroup\fR) for the \fIsysfs\fR \fIattribute\fR.
Where \fIowner\fR (and/or \fIgroup\fR) are any specification accepted by
\&\fBchown\fR\|(1).
.PP
Leading and trailing whitespace (SPACE, TAB), and whitespace around
the \fB=\fR character are ignored.
.PP
Comments start with a \fB#\fR character until the end of line.
Empty or whitespace-only lines are also ignored.
.PP
Any \fIattribute\fR that does not exist will be warned about, but will not cause
the loading to fail.
.SH FILES
.IX Header "FILES"
.IP \fI/etc/sysfs.conf\fR 4
.IX Item "/etc/sysfs.conf"
The main configuration file.
It gets loaded first if readable.
.IP \fI/etc/sysfs.d/*.conf\fR 4
.IX Item "/etc/sysfs.d/*.conf"
The optional configuration fragment files.
These get loaded after the main configuration file, if readable,
in glob order.
.SH EXAMPLES
.IX Header "EXAMPLES"
Always use the powersave CPU frequency governor.
.PP
.Vb 1
\&  devices/system/cpu/cpu0/cpufreq/scaling_governor = powersave
.Ve
.PP
Use userspace CPU frequency governor and set initial speed.
.PP
.Vb 2
\&  devices/system/cpu/cpu0/cpufreq/scaling_governor = userspace
\&  devices/system/cpu/cpu0/cpufreq/scaling_setspeed = 600000
.Ve
.PP
Set permissions of suspend control file.
.PP
.Vb 2
\&  mode power/state = 0660
\&  owner power/state = root:power
.Ve
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBsysfs\fR\|(5),
<https://www.kernel.org/doc/Documentation/filesystems/sysfs.txt>,
<https://www.kernel.org/doc/Documentation/ABI/stable/>.