RE: Cpufreq on k8 with xen dom0

[geaaru <geaaru@gmail.com>]

My current kernel version 2.6.22 (as previous versions 2.6.21, 2.6.20)
native works fine. Probably, there is a difference (as you said me)
between Xen ACPI Interpreter and the native mode interpreter.
I try also with xen-source-2.6.18 tree without xen support and in this
case, cpufreq works fine. Only if i enable xen cpufreq doesn't work.


On Fri, 2007-09-28 at 07:44 -0500, Langsdorf, Mark wrote: 
> > Hi, i try to use xen-unstable.hg version but doesn't work.
> > 
> > >From dmesg i have this error:
> > 
> > powernow-k8: Found 1 AMD Turion(tm) 64 Mobile Technology ML-30
> > processors (version 2.00.00)
> > powernow-k8: BIOS error - no PSB or ACPI _PSS objects
> > ACPI: (supports S0 S3 S4 S5)
> > 
> > While, if i try to call cpufreq-info i have this output:
> > 
> > cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
> > Report errors and bugs to linux@brodo.de, please.
> > analyzing CPU 0:
> >   no or unknown cpufreq driver is active on this CPU
> > 
> > any idea how can i resolve this problem?
> 
> dom0 isn't seeing the ACPI _PSS objects (I thought the
> error message made that clear).  No ACPI objects means
> no information on the pstates.
> 
> Do you get PowerNow! support on a native version 2.6.21+
> kernel?  If not, you need to update your BIOS to something
> that supports pstates (or possibly you have one of the
> rare Turions that doesn't support more than 1 pstate,
> but I doubt that).  
> 
> If 2.6.21+ native works, check to see if 2.6.18 native
> works.  If it doesn't, then there was a change to the
> ACPI interpreter to support your laptop that will need
> to be backported.  If 2.6.18 native works, then there's
> a difference between the Xen ACPI interpreter and the
> native mode interpreter that will need to be ported to
> Xen.
> 
> -Mark Langsdorf
> Operating System Research Center
> AMD
>