sparc64: Fix maybe_change_configuration() PCR setting.

Need to mask out the existing event bits before OR'ing in
the new ones.

Noticed by Peter Zijlstra.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 34ce49f80eac..2e1698332b6d 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -655,6 +655,7 @@ static u64 maybe_change_configuration(struct cpu_hw_events *cpuc, u64 pcr)
                 cpuc->current_idx[i] = idx;
 
                 enc = perf_event_get_enc(cpuc->events[i]);
+                pcr &= ~mask_for_index(idx);
                 pcr |= event_encoding(enc, idx);
         }
 out: