1 files changed, 20 insertions, 13 deletions

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 119917dbb81..7b6ee771c38 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -345,7 +345,14 @@ static void exynos4_mct_tick_start(unsigned long cycles,
 static int exynos4_tick_set_next_event(unsigned long cycles,
 				       struct clock_event_device *evt)
 {
-	struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
+	/*
+	 * In case of hotplugging non-boot CPU, the set_next_event could be
+	 * called on CPU0 by ISR before IRQ affinity is set to proper CPU.
+	 * Thus for accessing proper MCT Lx timer, 'per_cpu' for cpumask
+	 * in event must be used instead of 'this_cpu_ptr'.
+	 */
+	struct mct_clock_event_device *mevt = &per_cpu(percpu_mct_tick,
+			cpumask_first(evt->cpumask));
 
 	exynos4_mct_tick_start(cycles, mevt);
 
@@ -377,23 +384,13 @@ static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
 
 static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 {
-	struct clock_event_device *evt = mevt->evt;
-
-	/*
-	 * This is for supporting oneshot mode.
-	 * Mct would generate interrupt periodically
-	 * without explicit stopping.
-	 */
-	if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
-		exynos4_mct_tick_stop(mevt);
-
 	/* Clear the MCT tick interrupt */
 	if (__raw_readl(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) {
 		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
 		return 1;
-	} else {
-		return 0;
 	}
+
+	return 0;
 }
 
 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
@@ -401,6 +398,13 @@ static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 	struct mct_clock_event_device *mevt = dev_id;
 	struct clock_event_device *evt = mevt->evt;
 
+	/*
+	 * This is for supporting oneshot mode.
+	 * Mct would generate interrupt periodically
+	 * without explicit stopping.
+	 */
+	if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
+		exynos4_mct_tick_stop(mevt);
 	exynos4_mct_tick_clear(mevt);
 
 	evt->event_handler(evt);
@@ -463,7 +467,10 @@ static int __cpuinit exynos4_local_timer_setup(struct clock_event_device *evt)
 static void exynos4_local_timer_stop(struct clock_event_device *evt)
 {
 	unsigned int cpu = smp_processor_id();
+	struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
+
 	evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
+	exynos4_mct_tick_clear(mevt);
 	if (mct_int_type == MCT_INT_SPI)
 		if (cpu == 0)
 			remove_irq(evt->irq, &mct_tick0_event_irq);