[dpdk-stable] [PATCH v4] net/mlx5: fix mutex unlock in txpp cleanup

[Chengfeng Ye <cyeaa@connect.ust.hk>]

The lock sh->txpp.mutex was not correctly released if the function
returned in these two branches, which may led to deadlock if the
function was acquired again.

Fixes: d133f4cdb7 ("net/mlx5: create clock queue for packet pacing")
Cc: stable@dpdk.org

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
 drivers/net/mlx5/mlx5_txpp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_txpp.c b/drivers/net/mlx5/mlx5_txpp.c
index 4f6da9f2d1..0ece788a84 100644
--- a/drivers/net/mlx5/mlx5_txpp.c
+++ b/drivers/net/mlx5/mlx5_txpp.c
@@ -961,8 +961,12 @@ mlx5_txpp_stop(struct rte_eth_dev *dev)
 	MLX5_ASSERT(!ret);
 	RTE_SET_USED(ret);
 	MLX5_ASSERT(sh->txpp.refcnt);
-	if (!sh->txpp.refcnt || --sh->txpp.refcnt)
+	if (!sh->txpp.refcnt || --sh->txpp.refcnt) {
+		ret = pthread_mutex_unlock(&sh->txpp.mutex);
+		MLX5_ASSERT(!ret);
+		RTE_SET_USED(ret);
 		return;
+	}
 	/* No references any more, do actual destroy. */
 	mlx5_txpp_destroy(sh);
 	ret = pthread_mutex_unlock(&sh->txpp.mutex);
-- 
2.17.1