[dpdk-dev] [PATCH 21/24] mlx5: work around spurious compilation errors

[Nelio Laranjeiro <nelio.laranjeiro@6wind.com>]

From: Adrien Mazarguil <adrien.mazarguil@6wind.com>

Since commit "mlx5: resurrect TX gather support", older GCC versions (such
as 4.8.5) may complain about the following:

 mlx5_rxtx.c: In function `mlx5_tx_burst':
 mlx5_rxtx.c:705:25: error: `wqe' may be used uninitialized in this
     function [-Werror=maybe-uninitialized]

 mlx5_rxtx.c: In function `mlx5_tx_burst_inline':
 mlx5_rxtx.c:864:25: error: `wqe' may be used uninitialized in this
     function [-Werror=maybe-uninitialized]

In both cases, this code cannot be reached when wqe is not initialized.

Considering older GCC versions are still widely used, work around this
issue by initializing wqe preemptively, even if it should not be necessary.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 53d2a57..f4af769 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -591,7 +591,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 	unsigned int j = 0;
 	unsigned int max;
 	unsigned int comp;
-	volatile union mlx5_wqe *wqe;
+	volatile union mlx5_wqe *wqe = NULL;
 
 	if (unlikely(!pkts_n))
 		return 0;
@@ -733,7 +733,7 @@ mlx5_tx_burst_inline(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 	unsigned int j = 0;
 	unsigned int max;
 	unsigned int comp;
-	volatile union mlx5_wqe *wqe;
+	volatile union mlx5_wqe *wqe = NULL;
 	unsigned int max_inline = txq->max_inline;
 
 	if (unlikely(!pkts_n))
-- 
2.1.4