From: Thomas Renninger <trenn@suse.de>
To: "S K" <nospamnoham@gmail.com>
Subject: Re: cpufreq doesn't seem to work in Intel Q9300
Date: Sat, 9 Aug 2008 20:59:47 +0200
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Cc: "Alan Jenkins" <alan-jenkins@tuffmail.co.uk>,
       "Zhao Yakui" <yakui.zhao@intel.com>, linux-kernel@vger.kernel.org,
       linux-acpi@vger.kernel.org
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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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