[PATCH 3.14 010/228] clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup

Greg Kroah-Hartman gregkh at linuxfoundation.org
Wed Jun 4 16:20:39 PDT 2014


3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx at linutronix.de>

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: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

---
 drivers/clocksource/exynos_mct.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -432,6 +432,7 @@ static int exynos4_local_timer_setup(str
 				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);
 	}
@@ -452,7 +453,6 @@ static int exynos4_mct_cpu_notify(struct
 					   unsigned long action, void *hcpu)
 {
 	struct mct_clock_event_device *mevt;
-	unsigned int cpu;
 
 	/*
 	 * Grab cpu pointer in each case to avoid spurious
@@ -463,12 +463,6 @@ static int exynos4_mct_cpu_notify(struct
 		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);





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