RE: Frequency can't switch on a dual Turion 64

[Thomas Renninger <trenn@suse.de>]

On Sun, 2007-01-21 at 11:28 +0100, Romain Liévin wrote:
> Hi,
> 
> > It looks like the powernow-k8 driver correctly constructs
> > a two entry frequency table and verifies it, and then
> > reverifies a second frequency table with only 1 entry in
> > it.
> 
> I feel very strange that frequency range can vary ("request for
> verification of policy") between 2 calls of cpufreq_driver->verify() on
> the same CPU (cpufreq.c: 1386 & 1400). First call returns
> 800000-1600000MHz while the second one returns 800000-800000. Moreover,
> both calls are done before calling set_policy() at line 1413.
> 
> I think there is either a bug, either a problem with my configuration.
> Anyways, I'm investigating this by taking a look at source code.
> 
> I decided to debug this but I can load the powernow-k8 module once. I
> can't unload it; I have to reboot which is very annoying. Why module is
> locked?

In older kernels powernow-k8 could be unloaded, not sure whether this
is still the case. Switch to performance (or userspace?) governor and
try to unload all related modules, e.g. freq_tables,
maybe it still works.

I expect the limitation comes from ACPI _PPC func, so you should add
ACPI_DEBUG to your debug kernel and a printk into:
drivers/acpi/processor_perflib.c:acpi_processor_ppc_notifier()
to be sure.

Can you open a bugzilla.kernel.org bug and attach acpidump and add me
to CC, pls.

This sounds related to:
https://bugzilla.novell.com/show_bug.cgi?id=231107

You should also make sure your kernel includes this one, recently
posted here by Bruno Ducrot:
http://marc.theaimsgroup.com/?l=linux-acpi&m=116412804022222&w=2

     Thomas