Re: C states on AMD SMP

Janosch Machowinski
2005-09-09T10:08:09Z

Erik Slagter wrote:
> On Thu, 2005-09-08 at 13:53 +0200, Janosch Machowinski wrote:
>
>>Uhm Linux can't detect something, that is not given by your DSDT...
>>Even if the CPU and the Chipset support C80, als long as your DSDT does
>>not define these states, Linux can't detect them. Extract your DSDT,
>>decompile it and search it for the _CST and P_BLK structs. Then verify
>>if these structs acually contain C-States (There are some latency
>>restrictions for the C-States defined in the P_BLK, for more information
>>see www.acpi.info). If you done this please report back.
>
>
> Sorry, I am a newbie at this.
>
> I did this: cp /proc/acpi/dsdt .; iasl -d dsdt
>
> This yields a file called dsdt.dsl, which does not contain any string
> like _CST or P_BLK. What am I doing wrong here?
Ups my fault ;-)
The P_BLK is actually defined int the FADT...
And you do not have a _CST object, cause it would habe been decalared here :
Scope (\_PR)
{
Processor (CPU0, 0x00, 0x00008010, 0x06) {}
Processor (CPU1, 0x01, 0x00000000, 0x00) {}
}

The little 0x06 after CPU0 tells us that there is an P_BLK,
but like pavel told us, I think the OEM of the Mainboard disabled C2 and
C3, but you are free to verify it ;-)
Janosch

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