Re: Re: Centrino speedstep

Dominik Brodowski
2004-12-30T13:19:04Z

On Thu, Dec 30, 2004 at 12:07:23PM +0100, Bruno Ducrot wrote:
> On Thu, Dec 30, 2004 at 11:30:03AM +0100, Dominik Brodowski wrote:
> > On Thu, Dec 30, 2004 at 10:32:20AM +0100, Johan Vromans wrote:
> > > Dominik Brodowski <linux-X3ehHDuj6sIIGcDfoQAp7BvVK+yQ3ZXh@public.gmane.org> writes:
> > >
> > > > Yes, indeed. These seem to be the right places for modification.
> > >
> > > Okay, will do.
> > >
> > > However, that brings up an interesting question: what guarantees that
> > > the figures in the tables match the actual capabilities of the CPU?
> > > Currently, it seems that my 1.5Ghz CPU is happily running at 1.6Ghz.
> >
> > Run "x86info --mhz" and you'll most probably see the CPU runs at 1.5GHz
> > even though it is reported by ACPI as 1.6GHz.
> >
>
> Its maybe possible to get MSR MSR_IA32_PERF_STATUS and decode it in
> userspace?

The decoding is already there in cpufrequtils//debug/i386/centrino-decode.c,
someone just needs to adapt the MSR access as found in powernow-k8-decode.c
in same directory :)

Dominik