Re: [lm-sensors] Fintek f71882fg ACPI conflict

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Jun 28, 2012 at 12:00:56AM +0100, Michael Zintakis wrote:
> Hello Guenter and All,
> 
[ .. ]

> One last question (though this is more specific to the f71882fg
> driver): I have a procfs file called "pwmX_auto_pointY" (Y being

Do you mean sysfs ?

> from 1-5), which indicates the various pwm current value which is to
> be applied for different points: 4 being when the controlling
> temperature is low (the value of pwmX_auto_point4_temp to be
> precise) and 1 being where the current is at its maximum - normally
> 255.
> 
> Now, what is the purpose of pwmX_auto_point5 - does this hold the
> pwm value where the fan is in an idle state (i.e. the temperature is
> below pwmX_auto_point4_temp)? Because on all 3 fans, I have this set
> to 1, which, I am assuming is when the fans are stopped.
> 
Correct. 1 is too low, though. Default value per datasheet is 0x80.
Whatever it is, it should be high enough for the fans to start spinning.
The F71882FG does not have a register to set a "start spinning" pwm value,
so your minimum must guarantee that the fans do start to spin.

What is your setting for pwmX_enable ? It should probably be set to
automatic(2) so the chip can automatically control the fan speed depending
on the temperature.

> Even if I bring this value to some "idle" current, that won't help
> much because when I first boot the system, the fans are *always*
> still, so even if the idle state is >1, that won't help me much, so
> there must be another - better - way than using a script to
> "kickstart" the fans initially, surely!
> 
Maybe fan control is not set to automatic by the BIOS ?

Guenter