powerd on Sempron 3400+

[Scot Hetzel]

On 4/7/07, Evren Yurtesen <yurtesen at ispro.net> wrote:
> Scot Hetzel wrote:
> > On 4/7/07, Evren Yurtesen <yurtesen at ispro.net> wrote:
> >> >> Any suggestions on debugging it?
> >> >>
> >> > Try adding the following to /boot/loader.conf:
> >> >
> >> > hint.acpi_throttle.0.disabled="1"
> >> >
> >> > Scot
> >>
> >> Scot, as long as I dont run powerd, things do work fine. What does this
> >> setting do exactly?
> >>
> > It disables ACPI CPU throttling driver, which is the cause of the lock
> > ups when running powerd.
> >
>
> I will try it first thing tomorrow. I also see:
>
> dev.cpu.0.freq_levels: 1002/-1 939/-1 876/-1 814/-1 751/-1 688/-1 626/-1 563/-1 501/-1 438/-1 375/-1 313/-1 250/-1 187/-1 125/-1 62/-1
>
> Shouldnt it show ~1800 as a level? This is the processor
>
> CPU: AMD Sempron(tm) Processor 3200+ (1800.01-MHz 686-class CPU)
>  Origin = "AuthenticAMD"  Id = 0x40ff2  Stepping = 2
>  Features=0x78bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2>
>  Features2=0x2001<SSE3,CX16>
>  AMD Features=0xea500800<SYSCALL,NX,MMX+,FFXSR,RDTSCP,LM,3DNow+,3DNow>
>  AMD Features2=0x19<LAHF,<b3>,CR8>
>
> Bios DSDT seems to be reporting only 1800mhz and 800mhz (from PSS_ values)
>
> This is all very confusing, why do powerd try to set other values than the ones given by bios?
>

Because the ACPI CPU throttling driver is adding those extra
frequencies to the available frequencies.

Bruno Ducrot is aware of the problem and was going to take a look at
fixing the problem when he had some spare time.

On 1/12/07, Bruno Ducrot <ducrot at poupinou.org> wrote:
> Thanks you so much for your report.  That pretty strange, because I'm
> aware of problems when acpi_throttle hang when going to the lowest freq
> available, and the only way to "fix" this is to not allow that frequency
> by tweaking the sysctl debug.cpufreq.lowest (and is a known errata from
> some Intel southbridge btw).
>
> Well, I'll take a look at that one more closely.  On the other hand,
> since acpi_throttle don't save a lot of power (compared to powernow),
> I must admit this will be a low priority todo for me though.

NOTE: The strange ness he is refering to is that on my system, it hung
at a relatively high freq when ACPI CPU throttling was enabled.

Scot
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