iMac G5 Temperature control revisited

[Markus Demleitner]

Hi,

A while ago, benh posted a patch to improve SMU support on iMac G5s,
see
http://ozlabs.org/pipermail/linuxppc64-dev/2005-April/003835.html

I didn't really get to try it till now, but it still applies cleanly
to 2.6.13, which was a severe blow to my hopes someone else might
step in and improve iMac G5 support.

Now, for the benefit of others that might want to run linux on the
iMac G5, here's a quick hack that uses the above interface for fan
control.  It's more of a testbed but should work (you should
comment out the printks in benh's smu driver, though, if you run it
for extended periods of time).

It's a python script you can dump into /etc/init.d and then use as
you'd use other init scripts.

In case anyone else still uses the horrible g5-fanctl module I wrote
in April: Upgrading is worth it, benh's new asynchronous SMU interface
brings the CPU load of the temperature control down to basically
naught.

Here's the URL:
http://tucana.cl.uni-heidelberg.de/homepage/hacks/simpleTemp

Let me know if you use this script, because if others do (or want
to), I might actually write some docs.

I may give an in-kernel solution a shot, but given that I know
nothing about kernel-threads it's not likely right now -- if I find
time to hack on the kernel, I'd first like to get sound working and
then CPU frequency scaling.

Hints and tips regarding those two issues welcome and solicited...

Cheers,

         Markus