Re: [PATCH] drivers/cpufreq: Warn user when powernow-k8 tries to fall back to acpi-cpufreq and it is unavailable.

Borislav Petkov
2013-01-18T19:58:06Z

On Fri, Jan 18, 2013 at 07:38:34PM +0000, Matthew Garrett wrote:
> On Fri, Jan 18, 2013 at 08:36:56PM +0100, Borislav Petkov wrote:
>
> > Ok, how much can we rely on ACPI to have this ACPI_ADR_SPACE_SYSTEM_IO
> > properly set on K8? Because the thing is, we want to use acpi-cpufreq on
> > F10h onwards and leave powernow-k8 to K8s.
>
> SYSTEM_IO only supports single processors and was superceded in ACPI
> 2.0. Are there any single-core F10h?

Hmm, maybe some downcored creations, who knows? But actually, that
doesn't matter: we want to exit early from acpi-cpufreq loading on K8
only so the check should simply be:

if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
boot_cpu_data.x86 == 0xf) {
pr_debug(...)
...
}

Yeah, I think that should work. I'll add your patch to the others and
make a patchset to give it a run. If it looks good, we'll queue it for
3.9 so that it can see more testing.

Thanks.