[CentOS] Fan speed control on Supermicro X8DAL board with CentOS

Sun Feb 6 12:09:12 UTC 2011
Ned Slider <ned at unixmail.co.uk>

On 06/02/11 07:00, Chuck Munro wrote:
> Hello folks,
> I'm having a difficult time trying to figure out why the CPU cooling
> fans run at full speed on my Supermicro X8DAL-3 motherboard.  There
> doesn't seem to be any variable speed (the fans are PWM compatible) ...
> they either idle at almost nothing, or suddenly burst into a
> high-pitched scream that gets my ears bleeding after a few seconds.
> Once they jump to warp-10, they remain there.
> The "Super-I/O" chip on this board is a Winbond W83627DHG which does the
> temperature and voltage monitoring.
> Is anyone aware of which driver or kernel module I need for that chip in
> order to get control of the fans?  The Supermicro web site and the
> board's manual aren't any help.  Fresh installs of CentOS-5.5 and RHEL-6
> don't exert any control by default.  Installing the lm_sensors package
> and probing with the 'sensors' command didn't help either.
> Slowly going deaf .......
> Chuck

Hi Chuck,

The correct kernel module for your chipset is w83627ehf.ko. I'm not sure 
the driver actually controls fan speed, I thought it was more for 
monitoring (fan speeds, temps, voltages) but I could be wrong. My 
current system (not a Supermicro) controls variable fan speed from 
options within the BIOS. I can enable/disable fan speed control and 
select either voltage or PWM based control.

The stock w83627ehf driver in RHEL5.5 is oldish (they were updated in 
5.5 I think but are still over a year old now). ELRepo.org have an 
updated driver available (kmod-w83627ehf) based on a backport from 
kernel-2.6.34. I've just checked upstream and a few more patches have 
been committed since kernel-2.6.34 and the current kernel-2.6.37 so I'll 
look at updating the elrepo driver with those latest patches.

Hope that helps.