Messages in this thread | | | Date | Fri, 14 Jan 2011 11:28:45 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH] acpi/pm: If failed at validating ACPI PM timer, inhibit future reads. |
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On Fri, Jan 14, 2011 at 07:54:47AM -0800, john stultz wrote: > On Fri, 2011-01-14 at 07:44 -0800, john stultz wrote: > > I'm actually looking at a different fix, as I'm worried by Thomas' > > comment about hitting the same issue on real hardware if we catch the > > same pmtrm value both times. > > Konrad: Mind trying the following? > > > The conditional (!hpet && !ref_start && !ref_stop) doesn't really make > sense. If the refs are null, but hpet is on, we still want to break out. > > So checking if both the ref values are the same should handle if we > don't have hardware (both null) or if they are the same value (either by > invalid hardware, or by chance), which can cause a divzero issue. > > NOT FOR INCLUSION, I haven't had my coffee yet. > Signed-off-by: John Stultz <johnstul@us.ibm.com>
Works great. (I pulled out my patch to test this).
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 823f79a..fa2cb5e 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -935,7 +935,7 @@ static void tsc_refine_calibration_work(struct work_struct *work) > tsc_stop = tsc_read_refs(&ref_stop, hpet); > > /* hpet or pmtimer available ? */ > - if (!hpet && !ref_start && !ref_stop) > + if (ref_start == ref_stop) > goto out; > > /* Check, whether the sampling was disturbed by an SMI */ > > >
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