From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Fri, 3 Feb 2006 20:50:47 +0000 (+0100)
Subject: [PATCH] x86_64: Only switch to IPI broadcast timer on Intel when C3 is supported
X-Git-Tag: v2.6.16-rc3~200
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=76b461c21468f41837283b7888d55f1c0671f719;p=linux-2.6

[PATCH] x86_64: Only switch to IPI broadcast timer on Intel when C3 is supported

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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index be2dae52f6..3bfca093a8 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -899,7 +899,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
 		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);
 			}