Fan speed control

Related articles
lm_sensors
Undervolting CPU
CPU frequency scaling
Fan control can bring various benefits to your system, such as quieter working system and power saving by completely stopping fans on low CPU load.
Note
Laptop users should be aware about how cooling system works in their hardware. Some laptops have single fan for both CPU and GPU and cools both at the same time. Some laptops have two fans for CPU and GPU, but the first fan cools down CPU and GPU at the same time, while the other one cools CPU only. In some cases, you will not be able to use the
Fancontrol
script due to incompatible cooling architecture (e.g. one fan for both GPU and CPU). See
[1]
for some more information about this topic.
Warning
Configuring or completely stopping fans on high system load might result in permanently damaged hardware, or thermal throttling at best.
Fancontrol (lm-sensors)
This article or section needs language, wiki syntax or style improvements. See
Help:Style
for reference.
Reason:
This partially duplicates
lm_sensors#Configuration
, it should link there instead. (Discuss in
Talk:Fan speed control
)
fancontrol
is a part of
lm_sensors
, which can be used to control the speed of CPU/case fans. It is most suitable for desktops and laptops, where fan controls are available via
sysfs(5)
.
Support for newer motherboards may not yet be in the Linux kernel.
lm-sensors
Warning
The following command is safe by default (pressing
Enter
at each prompt). Some advanced options may damage hardware: only modify the defaults if you understand the implications.
The first thing to do is to run
# sensors-detect
This will detect all of the sensors present and they will be used for
fancontrol
. After that, run the following to check if it detected the sensors correctly:
$ sensors
coretemp-isa-0000
Adapter: ISA adapter
Core 0:      +29.0°C  (high = +76.0°C, crit = +100.0°C)
...
it8718-isa-0290
Adapter: ISA adapter
Vcc:         +1.14 V  (min =  +0.00 V, max =  +4.08 V)
VTT:         +2.08 V  (min =  +0.00 V, max =  +4.08 V)
+3.3V:       +3.33 V  (min =  +0.00 V, max =  +4.08 V)
NB Vcore:    +0.03 V  (min =  +0.00 V, max =  +4.08 V)
VDRAM:       +2.13 V  (min =  +0.00 V, max =  +4.08 V)
fan1:        690 RPM  (min =   10 RPM)
temp1:       +37.5°C  (low  = +129.5°C, high = +129.5°C)  sensor = thermistor
temp2:       +25.0°C  (low  = +127.0°C, high = +127.0°C)  sensor = thermal diode
Note
If the output does not display an RPM value for the CPU fan, one may need to
#Increase the fan divisor for sensors
. If the fan speed is shown and higher than 0, this is fine.
Configuration
Once the sensors are properly configured, use
pwmconfig(8)
to test and configure fan speed control. Following the guide should create
/etc/fancontrol
, a customized configuration file. In the guide, the default answers are in parenthesis if you press enter without typing anything. Enter
y
for yes,
n
for no.
# pwmconfig
Note
Some users may experience issues when using
/sys/class/hwmon/
paths for their configuration file.
hwmon
class device symlinks point to the absolute paths, and are used to group all of the
hwmon
sensors together into one directory for easier access. Sometimes, the order of the
hwmon
devices change from a reboot, causing
fancontrol
to stop working. See
#Device paths have changed in /etc/fancontrol
for more information on how to fix this.
Tweaking
Some users may want to manually tweak the configuration file after running
pwmconfig
with root privileges, usually to fix something. For manually tweaking the
/etc/fancontrol
configuration file, see
fancontrol(8)
for the variable definitions.
Users will probably encounter the
hwmon
path issues as noted above in
#Fancontrol (lm-sensors)
. See
#Device paths have changed in /etc/fancontrol
for more information.
Tip
Use
MAXPWM
and
MINPWM
options that limit fan speed range. See
fancontrol(8)
for details.
Note
Temperature and fan sensor paths could change as well (usually on a kernel update) (e.g.
hwmon0/device/temp1_input
becomes
hwmon0/temp1_input
). Check the
fancontrol.service
unit status
to find out which path is the troublemaker and correct your configuration file accordingly.
Running Fancontrol
Try to run
fancontrol
:
# fancontrol
A properly configured setup will not output errors and will take control of the system fans. Users should hear system fans starting shortly after executing this command.
fancontrol
can also be run by
starting/enabling
fancontrol.service
.
For an unofficial GUI,
install
fancontrol-gui
AUR
.
Fancontrol stops working after suspend–wake cycles
Unfortunately,
fancontrol
does not work after suspending. As per the
filed bug
, you will have to restart
fancontrol
after suspending. This can be achieved automatically by a
systemd hook
.
NBFC
Note
NBFC has been unmaintained since Mar 29, 2020. New user configs can still be created manually, however predefined configurations have not been added since that time. There are forks that exist to add new configs, such as
nbfc-revive
.
NBFC (NoteBook Fan Control) is a cross-platform fan control solution for notebooks, written in C# and works under
Mono
runtime. It comes with a powerful configuration system, which allows to adjust it to many different notebook models, including some of the latest ones.
There is another lightweight implementation of NBFC, written in C, named
NBFC-Linux
. It does not depend on the Mono framework. It can be installed as
nbfc-linux
AUR
.
Installation
NBFC can be installed as
nbfc
AUR
. Also
start/enable
nbfc.service
.
Configuration
NBFC comes with pre-made profiles. You can find them in
/opt/nbfc/Configs/
directory. When applying them, use the exact profile name without a file extension (e.g.
some profile.xml
becomes
"some profile"
).
Check if there is anything NBFC can recommend:
$ nbfc config -r
If there is at least one model, try to apply this profile and see how fan speeds are being handled. For example:
$ nbfc config -a "Asus Zenbook UX430UA"
Note
If you are getting
File Descriptor does not support writing
, delete
StagWare.Plugins.ECSysLinux.dll
[2]
and
restart
nbfc.service
:
# mv /opt/nbfc/Plugins/StagWare.Plugins.ECSysLinux.dll /opt/nbfc/Plugins/StagWare.Plugins.ECSysLinux.dll.old
If above solution did not help, try appending
ec_sys.write_support=1
to
kernel parameters
.
If there are no recommended models, go to
NBFC git repository
or
/opt/nbfc/Configs/
and check if there are any similar models available from the same manufacturer. For example, on
Asus Zenbook UX430UQ
, the configuration
Asus Zenbook UX430UA
did not work well (fans completelly stopped all the time), but
Asus Zenbook UX410UQ
worked fantastically.
Run
nbfc
to see all options. More information about configuration is available at
upstream wiki
.
Dell laptops
i8kutils
is a daemon to configure fan speed according to CPU temperatures on some Dell Inspiron and Latitude laptops. It uses the
/proc/i8k
interface provided by the
i8k
driver (an alias for
dell_smm_hwmon
). Results will vary depending on the exact model of laptop.
If fancontrol will not work on your system, use the
ignore_dmi=1
kernel module parameter
to load
dell_smm_hwmon
.
Warning
i8kutils
BIOS system calls stop the kernel for a moment on some systems (confirmed on Dell 9560), this can lead to side effects like audio dropouts, see
https://bugzilla.kernel.org/show_bug.cgi?id=201097
Installation
i8kutils
AUR
is the main package to control fan speed. Additionally, you might want to install these:
acpi
— must be installed to use
i8kmon
.
tcl
— must be installed in order to run
i8kmon
as a background service (using the
--daemon
option).
tk
— must be installed together with
tcl
to run as X11 desktop applet.
dell-bios-fan-control-git
AUR
— recommended if your BIOS overrides fan control.
Configuration
The temperature points at which the fan changes speed can be adjusted in the configuration file
/etc/i8kutils/i8kmon.conf
. Only three fans speeds are supported (high, low, and off). Look for a section similar to the following:
set config(0)  {{0 0}  -1  55  -1  55}
set config(1)  {{1 1}  45  75  45  75}
set config(2)  {{2 2}  65 128  65 128}
This example starts the fan at low speed when the CPU temperature reaches 55 °C, switching to high speed at 75 °C. The fan will switch back to low speed once the temperature drops to 65 °C, and turns off completely at 45 °C.
Tip
If when running
i8kmon
with the verbose option you notice that the state changes (example of an output:
# (57>=55), state=1, low=45, high=75
) but right and left fans report state 0, you might consider changing the speed value of the first state in the configuration file from default 1000 to 2000 or higher.
Installation as a service
i8kmon
can be started automatically by
starting/enabling
i8kmon.service
.
BIOS overriding fan control
Some newer laptops have BIOS fan control in place which will override the OS level fan control. To test if this the case, run
i8kmon
with verbose mode in a command line, make sure the CPU is idle, then see if the fan is turned off or turned down accordingly.
If the BIOS fan control is in place, you can try using
dell-bios-fan-control-git
AUR
:
Warning
Turning off BIOS fan control could result in damage to your hardware. Make sure you have
i8kmon
properly set up beforehand, or leave the CPU idle while you test this program.
To enable BIOS fan control:
# dell-bios-fan-control 1
To disable BIOS fan control:
# dell-bios-fan-control 0
BIOS fan control can be automatically disabled by
starting/enabling
dell-bios-fan-control.service
.
ThinkPad laptops
Some fan control daemons include
simpfand-git
AUR
and
thinkfan
AUR
(recommended).
Installation
Install
thinkfan
AUR
. Optionally, but recommended, install
lm_sensors
. If needed, a GUI is available with
thinkfan-ui
AUR
. Then have a look at the files:
# pacman -Ql thinkfan
Note that the
thinkfan
package installs
/usr/lib/modprobe.d/thinkpad_acpi.conf
, which contains the following
kernel module parameter
:
options thinkpad_acpi fan_control=1
Note
New Thinkpad models may require an additional
experimental=1
kernel module parameter. So, it is important to check fan functionality.
So fan control is enabled by default, but you may need you to manually
regenerate the initramfs
.
Now, reload the module with fan control enabled:
# modprobe -r thinkpad_acpi
# modprobe thinkpad_acpi fan_control=1
# cat /proc/acpi/ibm/fan
You should see that the fan level is "auto" by default, but you can echo a level command to the same file to control the fan speed manually:
# echo level 1 > /proc/acpi/ibm/fan
Fan Levels
Level
Effect
0
off
2
low speed
4
medium speed
7
maximum speed
auto
default - automatic, the fan RPM is controlled by the BIOS
full-speed / disengaged
the maximum fan speed; here the controller does not monitor the fan speed
The
thinkfan
daemon will do this automatically.
"7" is not the same as "disengaged". "7" is the maximum regulated speed (corresponds to "full-speed"). disengaged is the maximum unregulated speed.
See
ThinkWiki
for more details.
Finally,
enable
the
thinkfan.service
.
To configure the temperature thresholds, you will need to copy the example configuration file (
/usr/share/doc/thinkfan/examples/thinkfan.yaml
) to
/etc/thinkfan.conf
, and modify to taste. This file specifies which sensors to read, and which interface to use to control the fan. Some systems have
/proc/acpi/ibm/fan
and
/proc/acpi/ibm/thermal
available; on others, you will need to specify something like:
hwmon: /sys/devices/virtual/thermal/thermal_zone0/temp
to use generic
hwmon
sensors instead of thinkpad-specific ones.
A configuration example can be found in
Gentoo:Fan speed control/thinkfan#Configuration
.
Running
You can test your configuration first by running thinkfan manually (as root):
# thinkfan -n
and see how it reacts to the load level of whatever other programs you have running.
When you have it configured correctly,
start/enable
thinkfan.service
.
Lenovo Legions laptops
The tool
Lenovo Legion Linux
allows to change the fan curves that are stored in the embedded controller. It consists of a kernel module that must be compiled and loaded. Currently, there is no package, but it must be compiled and installed from source.
Then the fan curve can be set via the hwmon interface. This can be done with the provided script or the Python GUI.
ASUS laptops
This topic will cover drivers configuration on ASUS laptops for
Fancontrol (lm-sensors)
.
Kernel modules
In configuration files, we are going to use full paths to
sysfs
files (e.g.
/sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1
). This is because
hwmon
1
might change to any other number after reboot.
Fancontrol (lm-sensors)
is written in
Bash
, so using these paths in configuration file is completely acceptable. You can find complete
/etc/fancontrol
configuration file examples at
ASUS N550JV#Fan control
.
asus-nb-wmi
asus-nb-wmi
is a kernel module, which is included in the Linux kernel and is loaded automatically on ASUS laptops. It will only allow to control a single fan and if there is a second fan you will not have any controls over it. Note that blacklisting this module will prevent keyboard backlight to work.
Below are the commands to control it. Check if you have any controls over your fan:
# echo 255 > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1           # Full fan speed (Value: 255)
# echo 0 > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1             # Fan is stopped (Value: 0)
# echo 2 > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1_enable      # Change fan mode to automatic
# echo 1 > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1_enable      # Change fan mode to manual
# echo 0 > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/pwm1_enable      # Change fan mode to full speed
If you were able to modify fan speed with above commands, then continue with
#Generate configuration file with pwmconfig
.
asus_fan
asus_fan
is a kernel module, which allows to control both fans on some older ASUS laptops. It does not work with the most recent models.
Install the
DKMS
asus-fan-dkms-git
AUR
kernel module
, providing
asus_fan
:
# modprobe asus_fan
Check if you have any control over both fans:
# echo 255 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm1          # Full CPU fan speed (Value: 255)
# echo 0 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm1            # CPU fan is stopped (Value: 0)
# echo 255 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm2          # Full GFX fan speed (Value: 255)
# echo 0 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm2            # GFX fan is stopped (Value: 0)
# echo 2 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm1_enable     # Change CPU fan mode to automatic
# echo 1 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm1_enable     # Change CPU fan mode to manual
# echo 2 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm2_enable     # Change GFX fan mode to automatic
# echo 1 > /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/pwm2_enable     # Change GFX fan mode to manual
# cat /sys/devices/platform/asus_fan/hwmon/hwmon[[:print:]]*/temp1_input          # Display GFX temperature (will always be 0 when GFX is disabled/unused)
If everything works, you can
load the module at boot
to automate this step.
Generate configuration file with pwmconfig
If you get an error
There are no working fan sensors, all readings are 0
while generating configuration file with
pwmconfig
, open first console and execute:
# watch -n 1 "echo 2 > /sys/devices/platform/
kernel_module
/hwmon/hwmon[[:print:]]*/pwm
1
_enable"
If you use
asus_fan
kernel module and have 2nd fan, in second console:
# watch -n 1 "echo 2 > /sys/devices/platform/
kernel_module
/hwmon/hwmon[[:print:]]*/pwm
2
_enable"
And finally, in the third console:
# pwmconfig
Once you are done and the configuration file is generated, you should stop the first and second consoles. Continue with
#Fancontrol (lm-sensors)
. After the configuration file is generated, you might need to manually replace PWM values with full
sysfs
paths as they are used in these steps, because
hwmon
number values might change after reboot.
Alternative method using EC registers
If the above methods do not work for you, an alternative method is to directly write to certain registers in the embedded controller (EC). Using the
EC-Probe tool
, you can set the fan mode to one of the three fan speed modes, provided your model offers such feature in Windows.
In ASUS FX504GD model setting the fan speed to one of the three modes uses these register values:
# ec_probe write 0x5e 0x80 # silent mode
# ec_probe write 0x5e 0x40 # balance mode
# ec_probe write 0x5e 0xC0 # performance mode
Here we write to register
0x5e
that is responsible in setting the fan speed mode.
If these values do not work for you, run the
ec-probe
tool in monitor mode in Windows and try to identify which register in the EC changes value when switching through fan speed modes.
Setting thermal throttle policy
Instead of manually controlling fan speed using
asus-nb-wmi
, it is also possible to set the
thermal throttling policy
to have a more or less aggressive fan control policy. Possible values are
0
(default),
1
(overboost), and
2
(silent).
# echo
number
> /sys/devices/platform/asus-nb-wmi/hwmon/hwmon[[:print:]]*/throttle_thermal_policy
Fan control modes on certain TUF series laptops
On certain ASUS TUF series laptops, performance and fan control modes can be changed using
Fn+F5
. The current mode can be viewed by running the following command:
$ cat /sys/devices/platform/asus-nb-wmi/fan_boost_mode
Note
On some laptops, this setting may instead be at
/sys/devices/platform/asus-nb-wmi/throttle_thermal_policy
.
You can view the value changing as you use press
Fn+F5
. 0 is "Normal Mode", 1 is "Performance Mode", 2 is most likely "Silent Mode".
[3]
It is also possible to write these values into the
fan_boost_mode
file as root and have the desired effect.
This was tested on the ASUS TUF FX504GE and ASUS TUF FX504GD models and found to be working.
You can use
tuf-fan-boost-notification-git
AUR
to get notifications every time the FanSpeed mode gets changed.
AMDGPU sysfs fan control
AMDGPU
kernel driver offers fan control for graphics cards via
hwmon
in
sysfs
.
Manual fan control
To switch to manual fan control from automatic, run
# echo "1" > /sys/class/drm/card0/device/hwmon/hwmon0/pwm1_enable
Set up fan speed to e.g. 50% (100% are 255 PWM cycles, thus calculate desired fan speed percentage by multiplying its value by 2.55):
# echo "128" > /sys/class/drm/card0/device/hwmon/hwmon0/pwm1
To reset to automatic fan control, run
# echo "2" > /sys/class/drm/card0/device/hwmon/hwmon0/pwm1_enable
Warning
Resetting fan speed to auto may not work due to a driver bug and instead a restart of the driver may be required as a workaround.
Fan curves control
Newer AMD graphical cards such as RDNA3 graphical cards do not support manual fan control due to firmware limitations
[4]
. For these cases AMD provides a
fan_curve
sysfs api for controlling the fan curves, for more information on it see
[5]
.
amdgpu-fan
The
amdgpu-fan
AUR
package is an automated fan controller for AMDGPU-enabled video cards written in Python. It uses a "speed-matrix" to match the frequency of the fans with the temperature of the GPU, for example:
speed_matrix:  # -[temp(*C), speed(0-100%)]
- [0, 0]
- [40, 30]
- [60, 50]
- [80, 100]
Launch the fan control service by
starting/enabling
amdgpu-fan.service
.
amdfand-bin
Then
amdfand-bin
AUR
package is a native alternative to
amdgpu-fan
AUR
. Launch the fan control service by
starting/enabling
amdfand.service
.
For this tool there are also GUI clients available:
amdguid-glow-bin
AUR
(Xorg) and
amdguid-wayland-bin
AUR
(Wayland). Before starting the client you need to
enable/start
amdgui-helper.service
.
fancurve script
Not just fan controls are offered via
hwmon
in
sysfs
, but also GPU temperature reading:
# cat /sys/class/drm/card0/device/hwmon/hwmon0/temp1_input
This outputs GPU temperature in °C + three zeroes, e.g.
33000
for 33°C.
The bash script
amdgpu-fancontrol
by grmat offers a fully automatic fan control by using the described
sysfs hwmon
functionality. It also allows to comfortably adjust the fancurve's temperature/PWM cycles assignments and a hysteresis by offering abstracted configuration fields at the top of the script.
Tip
In order to function correctly, the script needs at least three defined temperature/PWM cycles assignments.
For safety reasons, the script sets fan control again to auto when shutting down. This may cause spinning up of fans, which can be worked around at cost of security by setting
set_fanmode 1
in the section
function reset_on_fail
.
Setting up fancurve script
To start the script, it is recommend to do so via
systemd
init system. This way the script's verbose output can be read via
journalctl
/systemctl status. For this purpose, a
.service
unit file is already included in the GitHub repository.
It may also be required to restart the script via a
root-resume.service
after hibernation in order to make it automatically function properly again:
/etc/systemd/system/root-resume.service
[Unit]
Description=Local system resume actions
After=suspend.target

[Service]
Type=simple
ExecStart=/usr/bin/systemctl restart amdgpu-fancontrol.service

[Install]
WantedBy=suspend.target
Others
fan2go-git
AUR
— An alternative to Fancontrol independent of device-paths.
mcontrolcenter-bin
AUR
— Fan control application for MSI laptops.
fw-ectool-git
AUR
— Fan configuration for
Framework Laptops
.
CoolerControl
AUR
— A fan control daemon with GUI for
sysfs
and
liquidctl
devices.
controlfans-git
AUR
— Simple GUI written in Qt to configure FAN PWM via HWMON interface. You could use it to setup the kernel auto point for every FAN who support it.
Troubleshooting
Increase the fan divisor for sensors
If
sensors
does not output the CPU fan RPM, it may be necessary to change the fan divisor.
The first line of the
sensors
output is the chipset used by the motherboard for readings of temperatures and voltages.
Create a file in
/etc/sensors.d/
:
/etc/sensors.d/fan-speed-control.conf
chip "
coretemp-isa-
*"
set fan
X
_div 4
Replacing
coretemp-isa-
with name of the chipset and
X
with the number of the CPU fan to change.
Save the file, and run as root:
# sensors -s
which will reload the configuration files.
Run
sensors
again, and check if there is an RPM readout. If not, increase the divisor to 8, 16, or 32. Your mileage may vary.
Device paths have changed in /etc/fancontrol
The enumerated
hwmon
symlinks located in
/sys/class/hwmon/
might vary in order because the kernel modules do not load in a consistent order per boot. Because of this, it may cause fancontrol to not function correctly. The error is "Configuration appears to be outdated, please run pwmconfig again".
Upstream bug
.
Solution
In
/etc/conf.d/lm_sensors
, there are 2 arrays that list all of the modules detected when you execute
sensors-detect
. These get loaded in by fancontrol. If the file does not exist, run
sensors-detect
as root, accepting the defaults. Open (or create)
/etc/modules-load.d/modules.conf
. Get all of the modules listed from the 2 variables in
/etc/conf.d/lm_sensors
and place them into the
/etc/modules-load.d/modules.conf
file, one module per line. Specifying them like this should make a defined order for the modules to load in, which should make the
hwmon
paths stay where they are and not change orders for every boot. If this does not work, I highly recommend finding another program to control your fans. If you cannot find any, then you could try using the alternative solution below.
Alternative solution: absolute paths
Using absolute file paths in fancontrol does not work by default, as its helper script
pwmconfig
is programmed to only use the
hwmon
paths to get the files. The way it does this is that it detects whether the
hwmon
path that is provided in its configuration file
/etc/fancontrol
did not change, and uses the variables
DEVNAME
and
DEVPATH
to determine such change. If your
hwmon
paths keep changing, this will prevent fancontrol from running no matter what you do. However, one can circumvent this problem. Open
/usr/bin/fancontrol
, and comment out this part of the script:
if [ "$DIR" = "/" -a -n "$DEVPATH" ]
then
   echo "Unneeded DEVPATH with absolute device paths" >&2
   exit 1
fi
if ! ValidateDevices "$DEVPATH" "$DEVNAME"
 then
     echo "Configuration appears to be outdated, please run pwmconfig again" >&2
     exit 1
 fi
Note
Doing this may make
fancontrol
write into files you gave it in the configuration file, no matter what the file is. This can corrupt files if you provide the wrong path. Be sure that you are using the correct path for your files.
Another thing to note is that while doing this workaround, using
pwmconfig
to create your script again will overwrite all of your absolute paths that you have configured. Therefore, it is better to manually change the old paths to the new paths if it is needed instead of using
pwmconfig
.
Commenting this out should effectively ignore the
hwmon
validation checks. You can also ignore the variables
DEVNAME
and
DEVPATH
in the configuration file as well. After this, replace all of the
hwmon
paths in the other variables with its absolute path. To make it easier, rerun
pwmconfig
with root privileges to refresh the
hwmon
devices. The
hwmon
paths in the configuration file should now point to the correct absolute paths. For each
hwmon
path, run the following command (where
N
is the enumeration of the
hwmon
path):
$ readlink -f /sys/class/hwmon/hwmon
N
/device
This will give you the absolute path of the device.
For example, an
/etc/fancontrol
file lists
FCTEMPS
as this:
FCTEMPS=hwmon2/pwm1=hwmon3/temp1_input
Executing
readlink -f /sys/class/hwmon/hwmon3/device
can, for example, output
/sys/devices/platform/coretemp.0/
.
cd
into this directory. If you see a
/hwmon/hwmon
N
/
directory, you have to do this in your
fancontrol
configuration file to replace the
hwmon
N
path. From the previous example:
# BEFORE
FCTEMPS=hwmon2/pwm1=hwmon3/temp1_input
# AFTER
FCTEMPS=hwmon2/pwm1=/sys/devices/platform/coretemp.0/hwmon/[[:print:]]*/temp1_input
Essentially, you must replace the
hwmon
path with the absolute path, concatenated with
/hwmon/[[:print:]]*/
so that bash can catch the random enumerated
hwmon
name.
If you do not see the
/hwmon/hwmon
N
/
directory, then you do not have to worry about this. This means that the temperature files are in the root of the device directory. Just replace
hwmon
N
/
with the absolute file path. For example:
# BEFORE
FCTEMPS=hwmon2/pwm1=hwmon3/temp1_input
# AFTER
FCTEMPS=hwmon2/pwm1=/sys/devices/platform/coretemp.0/temp1_input
After replacing all of paths,
fancontrol
should work fine.