[3.13.y.z extended stable] Patch "clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8200288dee2d51a13de2f864e4c3a594c0324955 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx at linutronix.de>
Date: Wed, 16 Apr 2014 14:36:45 +0000
Subject: clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup

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: Kamal Mostafa <kamal at canonical.com>
---
 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 62b0de6..b17b3e0 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);
--
1.9.1