Re: C states on AMD SMP

Janosch Machowinski
2005-09-08T11:53:05Z

Erik Slagter schrieb:
> Hi,
>
> I compiled & installed 2.6.13 (vanilla) on my Tyan Tiger S2466 (AMD768
> chipset, 2xathlon MP 2600) yesterday. Indeed, as expected, acpi
> "/proc/acpi/processor/*/power" (C states) is now supported on SMP. But,
> to my surprise, it only shows one C state (C1), which, I assume, is
> full-on. I am not completely sure about the CPU, but I do know that at
> least the chipset supports C2 and C3 states (even got it sort of working
> with pm_amd76x).
>
> Can someone shine some light on this?
>
> active state: C1
> max_cstate: C8
> bus master activity: 00000000
> states:
> *C1: type[C1] promotion[--] demotion[--]
> latency[000] usage[59379522]
>
> --- 8-< ----
>
> processor : 1
> vendor_id : AuthenticAMD
> cpu family : 6
> model : 8
> model name : AMD Athlon(tm) Processor
> stepping : 1
> cpu MHz : 2133.515
> cache size : 256 KB
> fdiv_bug : no
> hlt_bug : no
> f00f_bug : no
> coma_bug : no
> fpu : yes
> fpu_exception : yes
> cpuid level : 1
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow
> bogomips : 4266.27
>
> Thx.

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.
Janosch

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