[PATCH] arm_pmu: fix compiler warning in arm_pmu_device_probe

From: Chris Packham <chris.packham@alliedtelesis.co.nz>
To: mark.rutland@arm.com, will.deacon@arm.com
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Chris Packham <chris.packham@alliedtelesis.co.nz>
Subject: [PATCH] arm_pmu: fix compiler warning in arm_pmu_device_probe
Date: Thu,  2 Aug 2018 09:45:26 +1200	[thread overview]
Message-ID: <20180801214526.24599-1-chris.packham@alliedtelesis.co.nz> (raw)

GCC warns

  arm_pmu_platform.c:234:5: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This is because we rely on the for_each_cpu loop in armpmu_request_irqs
to initialise err. The warning is a little bogus because we know if
there were 0 CPUs this code would not be running.

Initialise err to 0 to avoid the warning.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
This has been reported before in https://lkml.org/lkml/2018/3/5/508 I'm not
sure if it was dismmissed as "meh, gcc is wrong" or if it was just wainting for
someone with some round tuits.


 drivers/perf/arm_pmu_platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
index 971ff336494a..96075cecb0ae 100644
--- a/drivers/perf/arm_pmu_platform.c
+++ b/drivers/perf/arm_pmu_platform.c
@@ -160,7 +160,7 @@ static int pmu_parse_irqs(struct arm_pmu *pmu)
 static int armpmu_request_irqs(struct arm_pmu *armpmu)
 {
 	struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
-	int cpu, err;
+	int cpu, err = 0;
 
 	for_each_cpu(cpu, &armpmu->supported_cpus) {
 		int irq = per_cpu(hw_events->irq, cpu);
-- 
2.18.0

