[dpdk-stable] [PATCH] net/mlx5: do not select legacy MPW implicitly

[Alexander Kozyrev]

The Legacy MPW (multi-packet write) should not be engaged implicitly.
We should exclude this function form a Tx burst routine selection process
unless it is requested specifically by setting the txq_mpw_en devarg.
Exclude this function from the selection process the same way it is done
for the Enhanced MPW in the mlx5_select_tx_function() routine.

Fixes: eb8121ab9dac ("net/mlx5: introduce Tx burst routine template")
Cc: stable at dpdk.org

Signed-off-by: Alexander Kozyrev <akozyrev at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 6a17a9a..df58af5 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -5542,6 +5542,9 @@ enum mlx5_txcmp_code {
 			/* Does not meet requested offloads at all. */
 			continue;
 		}
+		if ((olx ^ tmp) & MLX5_TXOFF_CONFIG_MPW)
+			/* Do not enable legacy MPW if not configured. */
+			continue;
 		if ((olx ^ tmp) & MLX5_TXOFF_CONFIG_EMPW)
 			/* Do not enable eMPW if not configured. */
 			continue;
-- 
1.8.3.1