Re: 2.6.22 regression: thermal trip points

[Thomas Renninger <trenn@suse.de>]

On Thu, 2007-08-02 at 11:45 +0200, Adrian Schröter wrote:
> On Thursday 02 August 2007 11:42:27 wrote Thomas Renninger:
> > On Thu, 2007-08-02 at 10:40 +0200, Knut Petersen wrote:
> > > Hi everybody!
> > >
> > > Kernel 2.6.22 decreases performance by about 50% on my system.
> > > No, I do not like that. The reason is a broken BIOS, granted, but there
> > > was a perfect workaround in the kernel that has been dropped.
> > >
> > > mainboard: AOpen i915GMm-hfs, AWARD BIOS
> > > cpu: Pentium-M 750 (0.8 to 1.86 MHz)
> > > openSuSE 10.2 with kernel 2.6.22.1
> >
> > Is this a DELL laptop that gets throttled by 75% to throttling state 6
> > if 60 degrees are exceeded?
> > Adrian has such a machine..., no idea what is going on with that one,
> > but only workaround to get any use out of this machine is to override at
> > least the passive trip point.
> 
> JFYI, there are plenty of these systems around, it was one out of four 
> standard Novell modells. I am mabye just the first one who uses Factory on 
> it, but expect more bugreports when 10.3 gets released ...

Oops. So this is not broken HW/BIOS, but definitely a kernel problem?
Only idea that comes to my mind finding this is to grep through the DSDT
and look out for code that accesses CPU throttling HW ports. Maybe ACPI
subsystem gets something wrong, processing this code and activating
throttling by accident?

Anyway, only solution/workaround to use these machines with current
kernels is to override trip points, maybe the patch should really just
be reverted...

   Thomas