Re: powernowd only 2 modes?
On Thu, Sep 22, 2005 at 09:50:28PM +0200, Ernest jw ter Kuile wrote:
> On Thursday 22 September 2005 14:49, Jo Shields wrote:
> > dmesg | grep powernow-k8
>
> anybody knows what this means ?
>
> terkuile:~$ dmesg | grep powernow-k8
> powernow-k8: Found 1 AMD Athlon 64 / Opteron processors (version 1.50.3)
> powernow-k8: BIOS error: maxvid exceeded with pstate 2
>
> I can find the error string in the kernel source code, however there is this
> amazing amount of comments associated with it. Google is also quite silent
> about this specific error.
There is a MSR onto the processor which will give what is the max
voltage (and the max multiplier as well) that can be applied to the
processor. When the driver parse a BIOS table in order to get the
supported pair of frequency/voltage, it detect that such an entry
is out of range. Therefore the driver bail out.
>
> Anybody else ever seen error above ?
There were some BIOS that give configurations for an XP-M instead of
an AMD64 and give the same error (though it was for a laptop).
By warning the OEM it was possible to make this work after a BIOS
upgrade. An other option is to hack the driver by hardcoding
a good table instead of the one supplied by the BIOS. Also
if you have ACPI enabled, you can correct that by hacking a
little the DSDT (or one of the SSDT). See
http://acpi.sf.net/ (for instruction on how to do so), and
the documentations I pointed to Mike in order to know what
to put for a corrected table.
--
Bruno Ducrot
-- Which is worse: ignorance or apathy?
-- Don't know. Don't care.
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