powernow-k8 and non-standard multipliers

powernow-k8 and non-standard multipliers

[Philip Langdale]

Hi Mark,

I've just upgraded to an X2 5000+ black edition. This model
doesn't have a multiple lock and I tried bumping the multiplier
up, which is perfectly stable, but which causes powernow-k8 to
fail to load. I also tried with the updated patch you posted
at the beginning of october (http://lkml.org/lkml/2007/10/9/224)
which didn't make a difference.

Is it possible to make the driver work in this situation or does
a non-standard multipler inherently mean that powernow stops
working?

Thanks,

--phil

RE: powernow-k8 and non-standard multipliers

[Langsdorf, Mark]

> I've just upgraded to an X2 5000+ black edition. This model
> doesn't have a multiple lock and I tried bumping the multiplier
> up, which is perfectly stable, but which causes powernow-k8 to
> fail to load. I also tried with the updated patch you posted
> at the beginning of october (http://lkml.org/lkml/2007/10/9/224)
> which didn't make a difference.
> 
> Is it possible to make the driver work in this situation or does
> a non-standard multipler inherently mean that powernow stops
> working?

The standard PowerNow! driver, by design, will stop 
working in this situation.  I'm not going to support
a driver that allows non-standard multipliers because
it could cause a lot of hard to debug maintenance
issues.

-Mark Langsdorf
Operating System Research Center
AMD

Re: powernow-k8 and non-standard multipliers

[Philip Langdale]

Langsdorf, Mark wrote:
> 
> The standard PowerNow! driver, by design, will stop 
> working in this situation.  I'm not going to support
> a driver that allows non-standard multipliers because
> it could cause a lot of hard to debug maintenance
> issues.

Just a follow-up to get this into the public record. I
discussed this with Mark privately and then did more
digging and established that in my particular case, the
problem was that the BIOS was hiding the p-state table
when a non-standard multiplier was used. So, I built
a custom DSDT that included the p-state table along
with an extra entry for my higher speed and now I've
happily got powernow support again.

--phil