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

Leonid Isaev
2013-01-18T01:40:44Z

[-- Attachment #1: Type: text/plain, Size: 3015 bytes --]

On Thu, 17 Jan 2013 10:46:48 +0100
Borislav Petkov <bp@alien8.de> wrote:

> 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.

Arrh, modprobe still does not exit cleanly with this...

>
> 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?

Udev 196 and 197 + linux <= 3.6.11 yield correct CPU autoprobing. However,
udev 197 + linux 3.7.2 do not. I haven't tested udev 196 with 3.7.2 though,
but it does not look like a udev issue.

I don't know if it matters, but I also have AMD microcode "0x10000c8", albeit
it didn't cause problems with 3.6.11...

>
> Btw, your config looks fine:
>
> CONFIG_X86_POWERNOW_K8=m
> CONFIG_X86_ACPI_CPUFREQ=m
>
> Thanks.
>

Sincerely,
L.
--
Leonid Isaev
GnuPG key: 0x164B5A6D
Fingerprint: C0DF 20D0 C075 C3F1 E1BE 775A A7AE F6CB 164B 5A6D

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 490 bytes --]