Re: Linux on new iMac G5 PowerMac12,1 -- OK, Windfarm???

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sun, 2006-01-22 at 21:54 -0500, Percy Zahl wrote:
> I now got a full running Debian Linux system setup on my iMac G5  
> PowerMac12,1 "i-Sight" using the 2.6.16-rc1 kernel and netinstall via  
> Debian etch.
> 
> -Network (eth0): OK
> -using append="video=ofonly": works OK
> -needed to disable any X attempts and gdm (crashes), console only  
> works OK. (No X)
> -build-in hardisk workes fine
> 
> I have one question about the windfarm stuff, what happens here?:
> 
> if I boot into Linux via yaboot directly (no OF commands), then the  
> Windfarm stays at some comfortable (and usual) slow speed for some  
> time, as I was playing around in linux suddenly it speeded up to max  
> and stayed there. What happens here, is there some kind of emergency  
> control already?

It's the hardware going into "watchdog" mode... The hardware detects it
hasn't been "ping" by the operating system for a while and ramps all
fans up.

Ben.