Messages in this thread | | | Date | Tue, 19 May 2009 17:24:44 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/2]cpuidle: makes AMD C1E works in acpi_idle |
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On Tue, 19 May 2009, Shaohua Li wrote:
> On Tue, May 19, 2009 at 08:55:10PM +0800, Thomas Gleixner wrote: > > On Tue, 19 May 2009, Shaohua Li wrote: > > > > > When AMD C1E is enabled, local APIC timer will stop even in C1. This patch uses > > > broadcast ipi to replace local APIC timer in C1. > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=13233 > > > > Hmm. This was addressed before in > > > > commit a8d6829044901a67732904be5f1eacdf8539604f (x86: prevent C-states > > hang on AMD C1E enabled machines) > > > > We limit C-States to 1 via acpi_processor_cstate_check(). > > > > And we have the broadcast logic in c1e_idle() already. We also select > > c1e_idle as the idle routine, so why is the ACPI code not using this. ? > > We used to call pm_idle_save() for C1, which will call c1e_idle. But this is > removed, guess the reason is we want to do C1 enter per the information gotten > from BIOS. So this bug is a regression actually. The patch follows the logic > of c1e_idle().
Hmm, ok. As long as the code does not undo something which was already set up in c1e_idle() I have no objections.
Thanks,
tglx
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