Hello.

I have a Lenovo Thinkpad R61 laptop and I'm trying to set up correctly 
fancontrol on it.

First of all, I loaded the thinkpad-acpi kernel module with the 
fan_control=1 option, otherwise the following steps don't work.

Then I ran pwmconfig in order to generate the /etc/fancontrol file.

Finally, I started fancontrol via "rc.d start fancontrol" (I'm running 
an Arch Linux system).

When idle, I get:
- fan1: 2604 RPM
- temp1: +40.0C

When busy, I get:
- fan1: 3176 RPM
- temp1: +65.0C

If now I stop fancontrol with "rc.d stop fancontrol" and wait some 
minutes, I get (system is stil busy):
- fan1: 4993 RPM
- temp1: +58.0C

That is, fan speed skyrocketed without any reason.

At http://www.kernel.org/doc/Documentation/laptops/thinkpad-acpi.txt I 
learned this is called "disengaged" mode, and it's not a safe mode to 
use. Let me quote:

 > There is also a "full-speed" level, also known as "disengaged" level.
In this level, the EC disables the speed-locked closed-loop fan control,
and drives the fan as fast as it can go, which might exceed hardware
limits, so use this level with caution.

I also noticed that while fancontrol is running, file 
/sys/class/hwmon/hwmon2/device/pwm1_enable is set to 1 (PWM manual), 
while when it quits that file is set to 0 (PWM disabled) instead of 2 
(PWM automatic). Why?

Beside this, I also tried manually setting PWM values in 
/sys/class/hwmon/hwmon2/device/pwm1, and I found that with values 
between 32 and 255 the fan runs, while with values between 0 and 31 the 
fan stops completely. My question is: MINSTART/MINSTOP should be both 32 
in my case?

Last thing. It seems the only values you can save into 
/sys/class/hwmon/hwmon2/device/pwm1 are: 255, 218, 182, 145, 109, 72, 36 
and 0. Other values get mapped to those previous values. Is this normal?

Thank you and sorry for the long message.