[patch added to the 3.12 stable tree] clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup

[Jiri Slaby]

From: Thomas Gleixner <tglx at linutronix.de>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 30ccf03b4a6a2102a2219058bdc6d779dc637dd7 upstream.

The starting cpu is not yet in the online mask so irq_set_affinity()
fails which results in per cpu timers for this cpu ending up on some
other online cpu, ususally cpu 0.

Use irq_force_affinity() which disables the online mask check and
makes things work.

Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Tested-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Cc: Kyungmin Park <kyungmin.park at samsung.com>
Cc: Marek Szyprowski <m.szyprowski at samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Cc: Tomasz Figa <t.figa at samsung.com>,
Cc: Daniel Lezcano <daniel.lezcano at linaro.org>,
Cc: Kukjin Kim <kgene.kim at samsung.com>
Cc: linux-arm-kernel at lists.infradead.org,
Link: http://lkml.kernel.org/r/20140416143316.106665251@linutronix.de
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Jiri Slaby <jslaby at suse.cz>
---
 drivers/clocksource/exynos_mct.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 62b0de6a1837..b17b3e0981f0 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -428,6 +428,7 @@ static int exynos4_local_timer_setup(struct clock_event_device *evt)
 				evt->irq);
 			return -EIO;
 		}
+		irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));
 	} else {
 		enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
 	}
@@ -448,7 +449,6 @@ static int exynos4_mct_cpu_notify(struct notifier_block *self,
 					   unsigned long action, void *hcpu)
 {
 	struct mct_clock_event_device *mevt;
-	unsigned int cpu;
 
 	/*
 	 * Grab cpu pointer in each case to avoid spurious
@@ -459,12 +459,6 @@ static int exynos4_mct_cpu_notify(struct notifier_block *self,
 		mevt = this_cpu_ptr(&percpu_mct_tick);
 		exynos4_local_timer_setup(&mevt->evt);
 		break;
-	case CPU_ONLINE:
-		cpu = (unsigned long)hcpu;
-		if (mct_int_type == MCT_INT_SPI)
-			irq_set_affinity(mct_irqs[MCT_L0_IRQ + cpu],
-						cpumask_of(cpu));
-		break;
 	case CPU_DYING:
 		mevt = this_cpu_ptr(&percpu_mct_tick);
 		exynos4_local_timer_stop(&mevt->evt);
-- 
1.9.3