drivers/perf: arm_pmu: Fix reference count of a device_node in of_pmu_irq_cfg

The only function called by of_pmu_irq_cfg that will increment the
reference count on dn is of_parse_phandle.

Each time we successfully parse a possible CPU from an
interrupt-affinity property, we increment the refcount of that CPU node
once via of_parse_handle. After validating the CPU is possible, we
decrement the refcount once. Subsequently, we decrement the refcount
again, either as part of an early break if we don't have a matching SPI,
or as part of the end of the loop body.

This will lead to decrementing twice the refcounnt.
Remove the second pairs of call to of_node_put as nobody is using dn
between the first and second call to of_node_put.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index f2d01d4d9364..6401f0c9fb6e 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -950,17 +950,14 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
 
                 /* For SPIs, we need to track the affinity per IRQ */
                 if (using_spi) {
-                        if (i >= pdev->num_resources) {
-                                of_node_put(dn);
+                        if (i >= pdev->num_resources)
                                 break;
-                        }
 
                         irqs[i] = cpu;
                 }
 
                 /* Keep track of the CPUs containing this PMU type */
                 cpumask_set_cpu(cpu, &pmu->supported_cpus);
-                of_node_put(dn);
                 i++;
         } while (1);