Re: [arch-general] powernow-k8 fails to load with linux 3.7.2

Borislav Petkov
2013-01-17T09:46:48Z

On Wed, Jan 16, 2013 at 06:16:00PM -0600, Leonid Isaev wrote:
> > [ fixup Andre's address. ]
> >
> > On Wed, Jan 16, 2013 at 11:33:21PM +0100, Rafael J. Wysocki wrote:
> > > > down the frequancy, but is accompanied by an info-level kernel message
> > > > "acpi-cpufreq: overriding BIOS provided _PSD data".
> >
> > That just says that BIOS has crappy data and we're using our own.
>
> OK. Yes, my BIOS is broken, so I thought it was the reason why autoloading does
> not work.

Hmm, come to think of it, we're issuing this message on SMP on *all*
AMDs with HW_PSTATE. Andre, remind me again why we're doing this? We're
basically saying that we're overriding ACPI data but we still read it
out from acpi_perf_data and use *that* data to prepare the frequencies
table. What am I missing?

> To be more precise: "modprobe powernow-k8" returns a "no such device" error,

That's correct - we say ENODEV on your CPU which supports hardware
P-states and hand off to acpi-cpufreq which has that functionality now.

> but in kernel logs I see that acpi-cpufreq is indeed loaded:
> -------
> Jan 15 22:42:19 metal-0 kernel: [ 534.003995] acpi-cpufreq: overriding BIOS
> provided _PSD data
> Jan 15 22:42:32 metal-0 kernel: [ 547.122695] powernow-k8: this CPU is not
> supported anymore, using acpi-cpufreq instead.
> Jan 15 22:42:45 metal-0 kernel: [ 559.623068] powernow-k8: this CPU is not
> supported anymore, using acpi-cpufreq instead.
> -------
> (the CPU in question is phenom II x4 955). However, this is only after I
> attempt to _manually_ load powernow-k8 (the timestamps in [...] are ~6 mins
> after boot is completed). So the above-mentioned handoff seems to work, but
> please find attached my kernel config.

Ok, this is maybe the issue. What used to load powernow-k8 on your
distro before? Because basically it's enough if some script did
'modprobe powernow-k8' for the handoff to just work.

But, we also have the CPU autoprobing deal:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=644e9cbbe3fc032cc92d0936057e166a994dc246

so, *actually*, powernow-k8 should be loaded by default. I dunno, maybe
upgrade udev on your distro?

Btw, your config looks fine:

CONFIG_X86_POWERNOW_K8=m
CONFIG_X86_ACPI_CPUFREQ=m

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--