Re: ACPI PM Timer vs. C1 halt issue

From: john stultz
Date: Wed Mar 10 2004 - 16:52:56 EST


On Tue, 2004-03-09 at 14:45, Prakash K. Cheemplavam wrote:
> john stultz wrote:
> > On Tue, 2004-03-09 at 13:35, Prakash K. Cheemplavam wrote:
> >
> >>I found out what causes higher idle temps when using mm-sources and
> >>2.6.4-rc vanilla sources: If I use PM Timer as timesource, it seems the
> >>C1 halt isn't properly called, at least CPU disconnect doesn't seem to
> >>work, thus leaving my CPU as hot as without disconnect.
> [snip]
> >
> > Sounds like a bug. I'm not very familiar w/ the ACPI cpu power states,
> > is there anything you have to do to trigger C1 Halt? Or is it just
> > called in the idle loop?
>
> It should be called within the idle loop.

Hmm. I'm still stumped. Looking at acpi_processor_idle(), the C1 state
doesn't touch the ACPI PM timer. The C2 and C3 states do, but they just
read.

Dominik: Do you have a clue on this?

thanks
-john

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