Re: Centrino speedstep

Bruno Ducrot
2004-12-29T18:18:34Z

On Tue, Dec 28, 2004 at 10:26:53PM +0100, Dominik Brodowski wrote:
> On Tue, Dec 28, 2004 at 09:32:00PM +0100, Johan Vromans wrote:
> > Hi,
> >
> > On my Acer Travelmate 4000WLMi, with various 2.6.9 and 2.6.10 kernels
> > and patch sets, I keep getting the following message:
> >
> > speedstep-centrino: invalid ACPI data
> > speedstep-centrino: no table support for CPU model "Intel(R) Pentium(R) M processor 1.50GHz":
> >
> > (Some kernels report "Invalid control/status registers" instead of
> > "invalid ACPI data").
> >
> > My latest attempt was the stock 2.6.10 kernel, with ACPI patch set
> > acpi-20041210-2.6.10-rc3.diff, and a fixed DSDT. Still no success.
> >
> > Any help is appreciated.
>
> It looks like your notebook's BIOS does not report sufficient data to the
> speedstep-centrino cpufreq driver. Does the acpi-cpufreq driver work
> instead?
>

After looking the DSDT, this laptop do not support the _PDC switch, so
the cpufreq-centrino driver will not work. But it should work with the
acpi io driver though.

Interresting portion:

OperationRegion (MNVS, SystemMemory, 0x1FEECE59, 0x60)
Field (MNVS, AnyAcc, Lock, Preserve)
{
...
...
CLNM, 8,
...
}

Scope (_PR)
{
Processor (CPU0, 0x00, 0x00001010, 0x06)
{
Name (_PCT, Package (0x02)
{
ResourceTemplate ()
{
Register (SystemIO, 0x08, 0x00, 0x00000000000000B2)
},

ResourceTemplate ()
{
Register (SystemIO, 0x08, 0x00, 0x00000000000000B3)
}
})
Method (_PSS, 0, NotSerialized)
{
If (CLNM)
{
Return (CPSS)
}

Return (PPSS)
}

Name (CPSS, Package (0x01)
{
Package (0x06)
{
0x0640,
0x5DC0,
0x0A,
0x0A,
0x89,
0x00
}
})
Name (PPSS, Package (0x05)
{
... (follow 5 packages defining the 5 P-states)
}
})
Method (_PPC, 0, NotSerialized)
{
Return (0x00)
}
}

This also mean there is no way to get the ondemand governor (or any DVS
requiring low latency driver) to work with this one (unless hardcoding
a table in the cpufreq-centrino).

There is no _CST also, this means there is no C4 support :(

--
Bruno Ducrot

-- Which is worse: ignorance or apathy?
-- Don't know. Don't care.

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