Newbie with Fedora Core 4 PPC on Power Mac G5.

[Brian Durant]

On 29. jan 2006, at 2.01, Brian D. Carlstrom wrote:

> windfarm* is the newer set of thermal driver that will replace
> therm_pm72.c someday according to Benjamin Herrenschmidt.

<snip>

> Note he has a PowerMac9,1, which needs the windfarm_pm91.c driver.
>
> I have FC4 on six PowerMacs (one PowerMac7,2 and five PowerMac7,3) and
> on two of the 2.7GHz PowerMac7,3 machines I've been having overheating
> problem. There is a known bug in the 2.6.14 therm_pm72.c driver, which
> is patched in 2.6.15:
>
> commit 6ee7fb7e363aa8828b3920422416707c79f39007
> Author: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Date:   Mon Dec 19 11:24:53 2005 +1100
>
>     [PATCH] powerpc: g5 thermal overtemp bug
>
>     The g5 thermal control for liquid cooled machines has a small  
> bug, when
>     the temperatures gets too high, it boosts all fans to the max, but
>     incorrectly sets the liquids pump to the min instead of the max  
> speed,
>     thus causing the overtemp condition not to clear and the  
> machine to shut
>     down after a while. This fixes it to set the pumps to max speed  
> instead.
>     This problem might explain some of the reports of random  
> shutdowns that
>     some g5 users have been reporting in the past.
>
>     Many thanks to Marcus Rothe for spending a lot of time trying  
> various
>     patches & sending log logs before I found out that typo. Note that
>     overtemp handling is still not perfect and the machine might still
>     shutdown, that patch should reduce if not eliminate such  
> occcurences in
>     "normal" conditions with high load. I'll implement a better  
> handling
>     with proper slowing down of the CPUs later.
>
>     Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>     Signed-off-by: Linus Torvalds <torvalds at osdl.org>
>
> However, when I switched to FC4 the updates-testing kernel to get the
> patch, now my fans run full blast as if no driver is talking to the
> hardware (as I saw when the PowerMac7,3 first came out and  
> therm_pm72.c
> did not check for it). Unfortunately the machines are in production  
> so I
> can't try FC5 at the moment, so for now I live the the noisy fans.
>
>> What problem are you having with the fans ? are they running at full
>> speed ? as root run 'modprobe therm_pm72' does that resolve the  
>> situation ?
>
> This does not work for me with the recent FC4 updates-testing kernel
> because the driver is not built as a module which I found odd. I  
> posted
> on fedora-test-list and got no followups.

I just thought that I would mention that I received an e-mail from  
Benjamin Herrenschmidt that contained the following:

From: 	  benh at kernel.crashing.org
> Oh, ok.. you mean the fans going full speed ? That's a matter of  
> thermal
> control not working on the machine. It's the single CPU G5 names
> PowerMac9,1 in /proc/device-tree/model right ?
>
> It should indeed work with recent kernels. I got some code in  
> 2.6.15 but
> there might still have been unresolved issues. Make sure you load the
> windfarm_pm91 module and let us know... If it doesn't work, try an  
> up to
> date git snapshot. If still doesn't work, let me know and we'll track
> the problem down.

This is hopefully of some help. I got this e-mail when I was trying  
to get Debian to work from the Etch installer. I believe it was  
Debian testing. Anyway, I don't really understand any of this. Sort  
of like a Concord going over my head ;-)

Cheers,

Brian