[PATCH] [1/2] x86_64: Fix C3 timer test

From: Andi Kleen
Date: Sat Oct 21 2006 - 18:52:59 EST



There was a typo in the C3 latency test to decide of the TSC
should be used or not. It used the C2 latency threshold, not the
C3 one. Fix that.

This should fix the time on various dual core laptops.

Signed-off-by: Andi Kleen <ak@xxxxxxx>

---
arch/x86_64/kernel/time.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)

Index: linux/arch/x86_64/kernel/time.c
===================================================================
--- linux.orig/arch/x86_64/kernel/time.c
+++ linux/arch/x86_64/kernel/time.c
@@ -948,7 +948,7 @@ __cpuinit int unsynchronized_tsc(void)
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
#ifdef CONFIG_ACPI
/* But TSC doesn't tick in C3 so don't use it there */
- if (acpi_fadt.length > 0 && acpi_fadt.plvl3_lat < 100)
+ if (acpi_fadt.length > 0 && acpi_fadt.plvl3_lat < 1000)
return 1;
#endif
return 0;
-
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