Messages in this thread | | | Date | Fri, 15 May 2009 10:27:55 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] ACPI: Idle C-states disabled by max_cstate should not disable the TSC |
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On Fri, 15 May 2009, Len Brown wrote:
> From: Len Brown <len.brown@intel.com> > > Processor idle power states C2 and C3 stop the TSC on many machines. > Linux recognizes this situation and marks the TSC as unstable: > > Marking TSC unstable due to TSC halts in idle > > But if those same machines are booted with "processor.max_cstate=1", > then there is no need to validate C2 and C3, and no need to > disable the TSC, which can be reliably used as a clocksource. > > Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
> --- > drivers/acpi/processor_idle.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index e39a40a..e65476f 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -582,7 +582,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) > > pr->power.timer_broadcast_on_state = INT_MAX; > > - for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { > + for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { > struct acpi_processor_cx *cx = &pr->power.states[i]; > > switch (cx->type) { > -- > 1.6.3.1.9.g95405b >
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