Re: 2.6.17 -> 2.6.18 regression: cpufreq broken since 2.6.18-rc1 on pentium4

From: Dave Jones
Date: Sun Jul 30 2006 - 15:00:57 EST


On Sun, Jul 30, 2006 at 08:44:43PM +0200, bert hubert wrote:

> > Do you have any info in /sys/devices/system/cpu/cpu0/cpufreq ?
>
> No, not with just acpi-cpufreq loaded. With the help of Zwane, I've
> discovered that if I unload acpi-cpufreq, I *can* load p4-clockmod, and then
> the directory you mention appears, and I can configure governors, and life
> is good. This all on 2.6.18-rc3.

Right, cpufreq drivers aren't 'stackable'.

> Do I understand correctly that acpi-cpufreq is supposed to offer comparable
> features?

If the BIOS supports the relevant ACPI tables.

> Perhaps acpi-cpufreq *has* loaded, but did not find the proper hooks, but
> has now registered itself, thus blocking p4-clockmod? When everything is
> in-kernel, acpi-cpufreq might register itself first, which would lead to the
> same thing.

Normally, if the necessary BIOS bits aren't there, then acpi-cpufreq will
fail to register. For some reason it sounds like it believes that everything
went ok. I wonder if something changed in acpi recently that caused this
change in behaviour ? Len ?

Dave

--
http://www.codemonkey.org.uk
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