[ltp] Re: tpfand configuration for an X200s

[Henrique de Moraes Holschuh]

On Sat, 20 Dec 2008, Christoph Bier wrote:
> Yes, see the subject ;-). Removing tpfand solved it. Thank you very
> much!

Urk. I should have noticed it.  Well, what's done, is done.

> So, once again ... you asked me do a throughout test of
> thinkpad-acpi fan control on my x200s and tell you what I find. I
> can set different levels---but the numeric ones from 0 to 6,
> 'disengaged', and 'disabled' last only for about 3 seconds then
> level goes back by itself to 'auto'; level 7 remains until I set a
> different level. 'full-speed' is ignored. Here's some data:

Looks like tpfand programmed the fan watchdog.  Just disable it, and the
levels will stick (and allow for easier testing):

echo 0 > /sys/bus/platform/drivers/thinkpad_hwmon/fan_watchdog

(or you can unload thinkpad-acpi and load it again with tpfand stopped :P)

Then you can redo the tests and the fan will stay at each level, and after a
small while you can see the RPM for that level (the fan may take some
seconds to change speed).

Disengaged might take a longer while to be noticed, though.  In a T43 it
takes several seconds to ramp up the fan to full speed, and while it is
doing that it won't even update the tachometer.  Other thinkpads behave a
bit differently.

> Fan speed significantly changed only with level 7 and 0 and
> 'disable' and 'enable'; but only level 7 remains.

Just disable the fan watchdog, and levels will stick around enough for the
fan to respond :)

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh