# Where are the pwm modules

## <3

Can someone please tell me what modules in the kernel I need in order to get fan control to work? The wiki doesn't seem to have this information.

```
#pwmconfig 

# pwmconfig revision 5857 (2010-08-22)

This program will search your sensors for pulse width modulation (pwm)

controls, and test each one to see if it controls a fan on

your motherboard. Note that many motherboards do not have pwm

circuitry installed, even if your sensor chip supports pwm.

We will attempt to briefly stop each fan using the pwm controls.

The program will attempt to restore each fan to full speed

after testing. However, it is ** very important ** that you

physically verify that the fans have been to full speed

after the program has completed.

/usr/sbin/pwmconfig: There are no pwm-capable sensor modules installed
```

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## NeddySeagoon

<3,

Use the serach in make menuconfig to find PWM

If that does't show anything interesting, press 'z' to show all the hidden symbols and run the seach again.

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## dlaor

As far as I understand it pwmconfig looks for drivers that allow it to read temperatures and to (accordingly) change the speeds of fans. E.g. for me the command returns

```
# pwmconfig revision 6166 (2013-05-01)

This program will search your sensors for pulse width modulation (pwm)

controls, and test each one to see if it controls a fan on

your motherboard. Note that many motherboards do not have pwm

circuitry installed, even if your sensor chip supports pwm.

We will attempt to briefly stop each fan using the pwm controls.

The program will attempt to restore each fan to full speed

after testing. However, it is ** very important ** that you

physically verify that the fans have been to full speed

after the program has completed.

Found the following devices:

   hwmon0 is acpitz

   hwmon1 is coretemp

   hwmon2/device is it8728

Found the following PWM controls:

   hwmon2/device/pwm1           current value: 70

hwmon2/device/pwm1 is currently setup for automatic speed control.

In general, automatic mode is preferred over manual mode, as

it is more efficient and it reacts faster. Are you sure that

you want to setup this output for manual control? (n)
```

So it has found three drivers, the second is the one for the processor and the third is the one for the motherboard sensors/controls. Both I have enabled under the "Device drivers" -> "Hardware monitor support" section of the kernel menuconfig.

I do not remember how you can find out which drivers to enable. (Also, of course, your motherboard might not be supported) I think the same procedure as with lm_sensors applies: enable them all, run sensors-detect to see which ones are getting used and then disable the rest.

Hope this helps!

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## <3

 *NeddySeagoon wrote:*   

> <3,
> 
> Use the serach in make menuconfig to find PWM
> 
> If that does't show anything interesting, press 'z' to show all the hidden symbols and run the seach again.

  I already have everything that could be found with the text string "pwm" compiled as a module. except for the few options that are greyed out.

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## Anon-E-moose

hw monitor under device drivers (as previously mentioned lm-sensors uses that also)

and possibly the acpi stuff

in my case it87 (super sensor hw chip) provides that.

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## <3

Here is a copy of my  Kernel Config file 

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## Anon-E-moose

I do not see any of the native drivers CONFIG_SENSORS_* set.

Which one you have depends on your motherboard.

I would suggest googling your "mb model" and "lm sensors" to see what others have set.

Set it in the kernel and run sensors-detect from the lm-sensors package to see if it is the correct one.

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## <3

Please ignore my previous post with the kernel config. I just went through that config and something is terribly wrong with it. A lot of options that I know for sure that should be enabled are for some reason disabled in it. For instance my root file system type was not enabled, wireless card drivers were not enabled. I suspect that my config file got corrupted and the kernel created a blank default config or something.

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