Re: Shuttle K48 and speedstep.

[Rasmus Wiman <rasmus@wiman.org>]

Len Brown <lenb@kernel.org> wrote:

> > Since speedstep with 45ns processors apparently works in windows,
> > would it be wrong to assume that windows (or whatever drivers
> > Shuttle provide for windows) keeps a bunch of extra SSDT:s around
> > and kludges them in if a 45ns CPU is present?
> > 
> > Both acpidumps are attached and if someone creates some kind of
> > patch I'll of course try it.
> 
> Your observation is correct.
> When the e2140 is installed, the RSDT has an SSDT in it
> that is absent when the 5300 is present.  The tables
> are otherwise identical.  The SSDT contains the _OSC,
> _PDC; and based on what happens at run-time, they load
> a dynamic SSDT which presumably includes the cpufreq
> related methods.  You will likely find that table
> under /sys/firmware/acpi/tables/dynamic/
> 
> (we should update acpidump to look there too).
> 
> So it looks like the BIOS doesn't recognize one of the CPUs,
> so i recommend that you look for an update.
> 
> Yes, I'm sure that Windows can handle speedstep on
> 45nm processors, and I'm sure that Linux can to --
> but not using the BIOS on this box.  Did you run
> windows on this BIOS and speedstep worked?
> That would be puzzling.

I didn't run windows on the box, Robert Szalai, who created the
original thread, claimed to have done it. But I just located a spare
hard drive, connected it to the K48 and installed Windows 7 beta on it.
And yes, according to CPU-Z speedstep is actually working using this
bios, with the 5300, on this box.

What's the next step from here? Could CPU-Z be lying? If I would
extract the ACPI tables from within windows, would they look the same
as they do when I do an acpidump from Linux? Is there a good tool for
extracting ACPI tables from within windows?

thanks,
Rasmus W