Re: cpufreq doesn't seem to work in Intel Q9300

Thomas Renninger
2008-08-09T18:43:28Z

On Friday 08 August 2008 08:23:25 pm S K wrote:
> > Try updating the BIOS.
> > I expect your CPU is too new and the BIOS cannot export the correct freq
> > values for the specific CPU yet.
> >
> > Thomas
>
> The BIOS is already at the latest version :( Is the above comment the
> only possible reason for the issue?

It is very likely.
I did not go through the DSDT table(s) myself, but if this is true:
> According to the online ACPI spec, the BIOS should expose _PCT, _PSS and PPC
> objects if it supports multiple CPU performance states (aka P-states,
> cpufreq).  I ran your acpidump.txt through acpixtract to generate the DSDT,
> and decompiled it using iasl.  It did not contain any of _PCT, _PSS and
> _PPC.

your BIOS does not export basic CPU freq data. The only way to get cpufreq
working on latest Intel HW is through ACPI and acpi-cpufreq driver.

It may happen that above functions are somewhat hidden in SSDT tables but
loading and finding the CPU freq functions generally works quite well.

Mark Langsdorf reported some acpi breakage in .27-rc1, this could also be the
reason.

That a BIOS update is needed for latest CPUs is common. I expect your machine
is rather new?

There also is a cpufreq list which moved recently, the latest one you should
post to is this one:
cpufreq@vger.kernel.org

Thomas
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