Re: frequency scaling on D525MW not working properly

[Sven Gaerner <sgaerner@xxxxxxx>]

On Fri, Aug 03, 2012 at 09:22:12AM +0800, Sepherosa Ziehau wrote:
> On Fri, Aug 3, 2012 at 2:00 AM, Sven Gaerner <sgaerner@gmx.net> wrote:
> > On Tue, Jul 31, 2012 at 09:27:15AM +0800, Sepherosa Ziehau wrote:
> >> On Tue, Jul 31, 2012 at 5:01 AM, Sven Gaerner <sgaerner@gmx.net> wrote:
> >> [...]
> >>
> >> Hmm, maybe i8254 is not working at all.  Could you post following information:
> >> - bootverbose dmesg w/ hw.i8254.intr_disable="0" in /boot/loader.conf
> >> - sysctl kern.cputimer
> >> - sysctl hw.acpi
> >
> > Attached the requested details.
> 
> Grrr, only C1 is detected.  If the CPU does support C3, there could be
> some settings in BIOS?
> 
> Best Regards,
> sephe
> 
> -- 
> Tomorrow Will Never Die

The BIOS settings are very limited. I did not find anything that looks
like configuring the C-states. You can just enable/disable the HPET
timer, the ACPI wake states (S1 or S3) and other settings that are not
related to ACPI/frequency scaling like configuring the USB ports.

It looks like FreeBSD also doesn't detect the settings well:
http://lists.freebsd.org/pipermail/freebsd-acpi/2011-August/007264.html

I guess there is no chance to get C3 states working. I looked into the
manual [1] and on page 28ff the table lists the expected power
consumption when the system is in various states. I did not see any C3
state there, only C1.

So I guess I have to use this board with the limitation or think about
changing to a board that supports frequency scaling.

Thanks for your support.

Regards,
Sven


[1] http://downloadmirror.intel.com/19123/eng/D525MW_D525MWV_TechProdSpec.pdf