1 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index decc5d294d76..377c3f8411f8 100644
--- a/arch/x86/kernel/i8253.c
+++ b/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)
 {
          /*