Messages in this thread | | | Date | Mon, 11 May 2009 11:00:19 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: [PATCH] ACPI: do not mark TSC unstable for invalid C-states |
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On Mon, 11 May 2009, Thomas Gleixner wrote:
> commit a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2 (ACPI: idle: > mark_tsc_unstable() at init-time, not run-time) marks TSC unstable > even on non affected systems. > > The reason is that the state enumeration does not check the cx->valid > flag before calling tsc_halts_in_c(), so it marks TSC unstable for any > enumerated albeit invalid C state which is known to turn off TSC. > > Check cx->valid before checking whether the TSC might become unstable. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> --- > drivers/acpi/processor_idle.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-2.6/drivers/acpi/processor_idle.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/processor_idle.c > +++ linux-2.6/drivers/acpi/processor_idle.c > @@ -583,7 +583,7 @@ static int acpi_processor_power_verify(s > > #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) > /* TSC could halt in idle, so notify users */ > - if (tsc_halts_in_c(cx->type)) > + if (cx->valid && tsc_halts_in_c(cx->type)) > mark_tsc_unstable("TSC halts in idle");; > #endif > switch (cx->type) { > > >
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