ARM: perf: simplify __hw_perf_event_init err handling

mrutland-arm · wildea01 · commit 9dcbf466559f · 2013-01-18T16:54:30.000Z
Currently __hw_perf_event_init has an err variable that's ignored right
until the end, where it's initialised, conditionally set, and then used
as a boolean flag deciding whether to return another error code.

This patch removes the err variable and simplifies the associated error
handling logic.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
@@ -350,7 +350,7 @@ __hw_perf_event_init(struct perf_event *event)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;
-	int mapping, err;
+	int mapping;
 
 	mapping = armpmu->map_event(event);
 
@@ -399,14 +399,12 @@ __hw_perf_event_init(struct perf_event *event)
 		local64_set(&hwc->period_left, hwc->sample_period);
 	}
 
-	err = 0;
 	if (event->group_leader != event) {
-		err = validate_group(event);
-		if (err)
+		if (validate_group(event) != 0);
 			return -EINVAL;
 	}
 
-	return err;
+	return 0;
 }
 
 static int armpmu_event_init(struct perf_event *event)

Original file line number	Diff line number	Diff line change
`@@ -350,7 +350,7 @@ __hw_perf_event_init(struct perf_event *event)`
`350`	`350`	`{`
`351`	`351`	`struct arm_pmu *armpmu = to_arm_pmu(event->pmu);`
`352`	`352`	`struct hw_perf_event *hwc = &event->hw;`
`353`		`- int mapping, err;`
	`353`	`+ int mapping;`
`354`	`354`
`355`	`355`	`mapping = armpmu->map_event(event);`
`356`	`356`
`@@ -399,14 +399,12 @@ __hw_perf_event_init(struct perf_event *event)`
`399`	`399`	`local64_set(&hwc->period_left, hwc->sample_period);`
`400`	`400`	`}`
`401`	`401`
`402`		`- err = 0;`
`403`	`402`	`if (event->group_leader != event) {`
`404`		`- err = validate_group(event);`
`405`		`- if (err)`
	`403`	`+ if (validate_group(event) != 0);`
`406`	`404`	`return -EINVAL;`
`407`	`405`	`}`
`408`	`406`
`409`		`- return err;`
	`407`	`+ return 0;`
`410`	`408`	`}`
`411`	`409`
`412`	`410`	`static int armpmu_event_init(struct perf_event *event)`