Re: Centrino question

[Dino Klein <zagzag-lists-zY4eFNvK5D9If6P1QZMOBw@public.gmane.org>]

I have an Acer C302, with a Pentium M 1.6, and the Intel 855GME chipset. 
The CPU/chipset supports C1 - C4.
My hypothesis as to why you don't have C3 is because it is disabled thru 
the value of the C3 latency in the FADT. The DSDT code probably has a 
_CST field/method for the processor, which specifies the available 
C-States. I've used a patch (from here 
http://bugzilla.kernel.org/show_bug.cgi?id=1958), that reads the _CST 
object.
Give it a try, and see if it solves your issue.


Cyril Wattebled wrote:
> Hi there,
> 
> I'm wondering if all Pentium M processor support C1 C2 and C3 ?
> Because I have a Sony Vaio Z1 with a Pentium M 1.7ghz and linux only detects C1
> and C2. I have a friend who has a Toshiba Tecra with a Pentium M 1.4ghz and it
> supports C3.
> I have heard that even C3 and C4 are supported by Centrinos.
> I'm using kernel 2.6.6-rc3. 
> Is there a logical answer why the kernel does only detect C1 and C3 ?
> Thanks
> 
> Cyril


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