Re: [PATCH 1/2] CPUFREQ: Enable acpi-cpufreq driver for VIA/Centaur CPUs

Michael S. Zick
2009-06-09T12:26:32Z

On Mon June 8 2009, Harald Welte wrote:
> On Mon, Jun 08, 2009 at 11:35:12AM -0700, Linus Torvalds wrote:
> > Hmm. This all really should be just
> >
> > static int check_est_cpu(unsigned int cpuid)
> > {
> > struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
> > return cpu_has(cpu, X86_FEATURE_EST);
> > }
> >
> > I suspect, with no vendor tests. That's the whole _point_ of CPU features,
> > after all.
>
> That's what I was thinking, too. If there was no such vendor test, it would
> have worked ever since the code was written (the C7 is by far not a new
> component, it's around for years).
>
> > If some vendor claims EST but doesn't actually support the EST interfaces,
> > we should just have fixups to clear the bit in the per-vendor cpuinfo
> > code, not in some random driver.
>
> agreed.
>
> > The only thing that makes me nervous about this is how close to 2.6.30 we
> > are. I'd be happier if this was resolved by doing this as a patch
> > post-2.6.30, and then adding 'stable@kernel.org' as a Cc: tag, and
> > backporting it to 2.6.30.1 if no problems appear.
> >
> > It's not like this is a regression, I think.
> >
> > Does that sound like a reasonable plan?
>
> Sounds fine with me. But what I would definitely suggest merging before 2.6.30
> is the marking e_powersaver EXPERIMENTAL + DANGEROUS patch.
>

As posted somewhere in this thread,
the acpi-cpufreq controller appears to work on my machine in initial tests.

A few tests on only one machine is not much to go on and it
isn't enough to call it "tested" but is forward progress.

I was only risking my "throw-away" machine yesterday, will see what
happens on the "good" one today (the HP-2133).

@H.W. - are you running any of these changes on your HP-2133?

Mike
> Regards,