[ltp] Re: tpfand configuration for an X200s

Elias Oltmanns linux-thinkpad@linux-thinkpad.org
Sun, 07 Dec 2008 12:51:01 +0100

Christoph Bier <christoph.bier@web.de> wrote:
> Henrique de Moraes Holschuh schrieb am 05.12.2008 19:37:
>> If the drivers make Windows waste less power, they are not interfering with
>> fan control but would STILL cause the fan to behave differently (because
>> there is less waste heat).
> Yes. But under Linux the fan is running at temperatures at which
> (right grammar?) the fan is not running under Vista. I would
> understand if the fan was running more often and even faster under
> Linux. But it's constantly running---at comparatively low temperatures.

Please keep in mind that there is not a trivial correlation between
temperature readings and fan speed. In particular, hysteresis enters
into it which can be easily observed on my X40. When I keep working for
a long time with active wlan but otherwise restricting myself to
lightweight tasks like reading emails, browsing the web, etc. and the
fan starts spinning eventually (this only happens in a reasonably warm
environment), then it won't stop for a very long time. On the other
hand, when I compile the kernel which challenges the CPU as well as the
HD, then temperature readings rise quickly and the fan gets into gear
accordingly. Quite shortly after compilation has completed, the fan
stops spinning at temperature readings that are well above the
thresholds that would have caused the fan to stop in the first scenario.

> What about my question on thinkpad_ec? Might it effect fan's
> behaviour? It fails to load on my X200s. Yesterday I tried to
> install a vanilla kernel (to be able to possibly file a bug in the
> Kernel Bug Tracker) but compilation failed for reasons I do not
> understand yet.

As Henrique said, thinkpad_ec is not directly related to fan control.
But why would you want to file a bug against the vanilla kernel when
thinkpad_ec wouldn't load? This module is not even part of mainline.