From 53944085b75f1cebecdd5a33628d8187d4c3ea29 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Thu, 4 Sep 2008 22:47:47 +0200
Subject: [PATCH] --- yaml --- r: 110436 b: refs/heads/master c:
 4156e9a8ef5b521185f451213d33fa661f38512e h: refs/heads/master v: v3

---
 [refs]                      | 2 +-
 trunk/arch/x86/kernel/tsc.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 7309ca6a13a1..33eed19173b6 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6ac40ed0413ef4096720f966e11c7cdf259eee3f
+refs/heads/master: 4156e9a8ef5b521185f451213d33fa661f38512e
diff --git a/trunk/arch/x86/kernel/tsc.c b/trunk/arch/x86/kernel/tsc.c
index 839070ba8465..6dab90f68515 100644
--- a/trunk/arch/x86/kernel/tsc.c
+++ b/trunk/arch/x86/kernel/tsc.c
@@ -316,6 +316,12 @@ static unsigned long quick_pit_calibrate(void)
 		}
 		t2 = get_cycles();
 
+		/*
+		 * Make sure we can rely on the second TSC timestamp:
+		 */
+		if (!pit_expect_msb(--expect))
+			goto failed;
+
 		/*
 		 * Ok, if we get here, then we've seen the
 		 * MSB of the PIT decrement QUICK_PIT_ITERATIONS