[PATCH 5/8] powerpc/perf: Don't enable if we have zero events

[Michael Ellerman]

In power_pmu_enable() we still enable the PMU even if we have zero
events. This should have no effect but doesn't make much sense. Instead
just return after telling the hypervisor that we are not using the PMCs.

Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
 arch/powerpc/perf/core-book3s.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index af4b4b1..d3ee2e5 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -926,6 +926,11 @@ static void power_pmu_enable(struct pmu *pmu)
 	if (!cpuhw->disabled)
 		goto out;
 
+	if (cpuhw->n_events == 0) {
+		ppc_set_pmu_inuse(0);
+		goto out;
+	}
+
 	cpuhw->disabled = 0;
 
 	/*
@@ -937,8 +942,6 @@ static void power_pmu_enable(struct pmu *pmu)
 	if (!cpuhw->n_added) {
 		mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
 		mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
-		if (cpuhw->n_events == 0)
-			ppc_set_pmu_inuse(0);
 		goto out_enable;
 	}
 
-- 
1.7.10.4