Only switch to IPI broadcast timer on Intel when C3 is supported

From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

Bug in apic timer removal on C3 patch. We should switch to IPI from APIC timer
only when C3 state is valid.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>

 drivers/acpi/processor_idle.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

Index: linux/drivers/acpi/processor_idle.c
===================================================================
--- linux.orig/drivers/acpi/processor_idle.c
+++ linux/drivers/acpi/processor_idle.c
@@ -899,7 +899,7 @@ static int acpi_processor_power_verify(s
 		case ACPI_STATE_C3:
 			acpi_processor_power_verify_c3(pr, cx);
 #ifdef ARCH_APICTIMER_STOPS_ON_C3
-			if (c->x86_vendor == X86_VENDOR_INTEL) {
+			if (cx->valid && c->x86_vendor == X86_VENDOR_INTEL) {
 				on_each_cpu(switch_APIC_timer_to_ipi,
 						&mask, 1, 1);
 			}