Re: e_powersaver driver considered DANGEROUS (was Re: Linux2.6.30-rc8 [also: VIA Support])

From: Pavel Machek
Date: Mon Jun 08 2009 - 10:58:21 EST


> > > Ah, but we are talking here of the *second* NetBook ever produced.
> > > If one is to believe the dmidecode output - it is using the VIA demo board
> > > BIOS.
> > >
> > > I bet the demo board BIOS is intended to demo the features of the product -
> > > not the correctness or completeness of the ACPI support. ;)
> So I've just been told the VIA reference BIOS has full support for the
> processor p-state support. I'd therefore suppose every production BIOS
> contains that code, too. The kernel should never use a native driver such as
> e_powersaver on any C7 or Nano system, but use the ACPI provided
> tables/methods, which are intel compatible. A native driver would only be
> needed on really old C3 systems.
> The e_powersaver.c driver neither respects the maximum/minimum frequency
> constraints specified in the MSR's, nor does it take care of the inflection
> ratio, parallax and other advanced stuff that C7 and Nano are doing in this
> area.

Uhuh, what is inflection ratio/parallax?

I did play with cpufreq on intel/amd systems, and never heard about


(cesky, pictures)
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