Subject: Re: [PATCH 00/15] PowerMac i2c API conversions & windfarm updates

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 26 Apr 2012 07:14:25 +1000

On Wed, 2012-04-25 at 12:29 +0200, Andreas Schwab wrote:
> Benjamin Herrenschmidt <[email-masked]> writes:
> 
> > Also, does the new driver properly react to load ?
> 
> The old driver keeps the cpu fans running at 300 rpm (lowest speed?)
> for much longer when the cpus are put busy.  Only when the cpus are back
> idle it speeds them up to 1200 rpm or more for some time depending on
> how long the cpus were busy.  The new driver is faster at speeding up
> the fans to around 800 rpm when cpus get busy, and keeps them running
> longer at that speed, but doesn't appear to select much higher speeds.
> 
> The old driver appears to be better suited to desktops, whereas the new
> driver is probably better for servers.

That's odd... as I said, the algorithm is supposed to be the same...

> But the most annoying sound appears to be coming from the slots fan.

Constant or changing ? The slots fan is set to a fixed speed, which I
thought was constant (well, I "tickle" it a bit but roughly it's
constant). Or is that not the case for you ?

Darwin has an algorithm for it based on getting some data from the video
driver in the AGP slot, but I don't have that.

Cheers,
Ben.