Re: p4-clockmod doesn't seem to allow the highest possible speed

[Wouter Verhelst <wouter@grep.be>]

On Sun, Jan 11, 2004 at 06:35:47PM +0100, Dominik Brodowski wrote:
> On Sat, Jan 10, 2004 at 08:35:26PM +0100, Wouter Verhelst wrote:
> > That happens both when it's in P0 or P1.
> 
> So ACPI works to set the processor in P0 and P1?

Yes.

> If so, you really really should use the ACPI cpufreq driver instead of
> the p4-clockmod driver. The former will offer you true "SpeedStep"
> support, the latter only some clock modulation which won't save you
> much energy as ACPI supports the C2 idle state anyway. 

Ah, so what p4-clockmod does is not SpeedStep?

Hm. That sucks.

> > Not that it matters -- p4-clockmod seems to do it right :)
> 
> It's not as noisy, indeed. But it's not right -- as long as acpi.ko works.

It mostly does, although I've had lockups when using the /proc interface
to switch CPU frequencies -- yes, should've reported that, but I only
now remember :)

> > > I think ACPI is messing with us. It detects a high temperature
> > > situation, tries to scale down the CPU, and forces down the CPU speed.
> > 
> > Hm. This one got me thinking; I think I just found it. I forgot that I
> > installed cpufreqd a while ago, which seems to be the culprit: when I
> > start cpufreqd, the system falls back to 1925Mhz. I've removed it now,
> > however, as killing cpufreqd does not release the maximum speed back to
> > it's normal value of 2.2Ghz, I'm not entirely sure; so...
> > 
> > > Could you send me the output of /proc/acpi/processor/*/* and
> > > /proc/acpi/thermal_zone/*/* when you notice this situation again?
> > 
> > ... I've still put those at
> > http://users.pandora.be/wouter.verhelst/proc-acpi.tgz
> 
> Hm, can't recognize anything strange there. When the situation appears
> again, what does /sys/devices/sytem/cpu/cpu0/cpufreq/scaling_max_freq say?

That does not change.

-- 
Wouter Verhelst
Debian GNU/Linux -- http://www.debian.org
Nederlandstalige Linux-documentatie -- http://nl.linux.org
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"So is my neck, stop it anyway!"
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