From e56fd241351c2de2c2f2589488fbaac73dcdadab Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 30 Jan 2008 13:30:03 +0100
Subject: [PATCH] --- yaml --- r: 79698 b: refs/heads/master c:
 1a0c009ac53de4a7664a1239936f0bc258133156 h: refs/heads/master v: v3

---
 [refs]                        |  2 +-
 trunk/arch/x86/kernel/i8253.c | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 29e055336e3a..50fe8e647547 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4713e22ce81eb8b3353e16435362eb3d0ec95640
+refs/heads/master: 1a0c009ac53de4a7664a1239936f0bc258133156
diff --git a/trunk/arch/x86/kernel/i8253.c b/trunk/arch/x86/kernel/i8253.c
index decc5d294d76..377c3f8411f8 100644
--- a/trunk/arch/x86/kernel/i8253.c
+++ b/trunk/arch/x86/kernel/i8253.c
@@ -18,6 +18,12 @@
 DEFINE_SPINLOCK(i8253_lock);
 EXPORT_SYMBOL(i8253_lock);
 
+#ifdef CONFIG_X86_32
+static void pit_disable_clocksource(void);
+#else
+static inline void pit_disable_clocksource(void) { }
+#endif
+
 /*
  * HPET replaces the PIT, when enabled. So we need to know, which of
  * the two timers is used
@@ -52,11 +58,13 @@ static void init_pit_timer(enum clock_event_mode mode,
 			outb_p(0, PIT_CH0);
 			outb_p(0, PIT_CH0);
 		}
+		pit_disable_clocksource();
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:
 		/* One shot setup */
 		outb_p(0x38, PIT_MODE);
+		pit_disable_clocksource();
 		break;
 
 	case CLOCK_EVT_MODE_RESUME:
@@ -196,6 +204,17 @@ static struct clocksource clocksource_pit = {
 	.shift	= 20,
 };
 
+static void pit_disable_clocksource(void)
+{
+	/*
+	 * Use mult to check whether it is registered or not
+	 */
+	if (clocksource_pit.mult) {
+		clocksource_unregister(&clocksource_pit);
+		clocksource_pit.mult = 0;
+	}
+}
+
 static int __init init_pit_clocksource(void)
 {
 	 /*