ACPI throttling changes

[Nate Lawson]

On Thu, 11 Dec 2003, Ducrot Bruno wrote:
> On Wed, Dec 10, 2003 at 10:06:45AM -0800, Nate Lawson wrote:
> > On Wed, 10 Dec 2003, Lukas Ertl wrote:
> > > On Tue, 9 Dec 2003, Nate Lawson wrote:
> > > > I'm working on a shared CPU frequency control driver.  One step is to
> > > > remove some of the autonomy of the throttling portion of acpi_cpu.
> > > > Please test this patch if you have a machine which supports throttling.
> > >
> > > Apropos CPU frequency: is there a way to find out at what frequency the
> > > CPU is running?  And shouldn't SpeedStep have an influence on that?  (Or
> > > is SpeedStep not supported?)
> >
> > This is getting a bit off-topic.  It's too early to discuss how all the
> > different parts of cpufreq work.  The answer is "yes and no", depending on
> > which underlying technologies your laptop has available.  ACPI throttling:
> > yes, SpeedStep: mostly yes, ACPI performance states: no.
>
> ACPI performance states (IO only though) should be ok, no?

There's no way to read the current ACPI performance state value.  The only
thing you can do is set a performance state and validate that it
succeeded.

-Nate