From: Pawel Moll <pawel.moll@arm.com>
Date: Thu, 15 Oct 2015 13:32:46 +0000 (+0100)
Subject: bus: arm-ccn: Fix irq affinity setting on CPU migration
X-Git-Tag: v4.2.6~75
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c7ee1f4f161b844c7388528f38fb3d7eb96d078f;p=thirdparty%2Fkernel%2Fstable.git

bus: arm-ccn: Fix irq affinity setting on CPU migration

commit a0bcbe969f564d1ec08658170dda72a1b7e9053a upstream.

When PMU context is migrating between CPUs, interrupt affinity is set as
well. Only this should not happen when the CCN interrupt is not being
used at all (the driver is using a hrtimer tick instead).

Fixed now.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 7d9879e166cf4..395cb7f9f5a4e 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -1188,7 +1188,8 @@ static int arm_ccn_pmu_cpu_notifier(struct notifier_block *nb,
 			break;
 		perf_pmu_migrate_context(&dt->pmu, cpu, target);
 		cpumask_set_cpu(target, &dt->cpu);
-		WARN_ON(irq_set_affinity(ccn->irq, &dt->cpu) != 0);
+		if (ccn->irq)
+			WARN_ON(irq_set_affinity(ccn->irq, &dt->cpu) != 0);
 	default:
 		break;
 	}