[PATCH] net/mlx5: fix shared Rx queue config reuse

[Alexander Kozyrev]

There is a check for the configuration match between
all the Rx queues shared among multiple ports in DPDK.
This check ensures that the configuration is the same.

The issue is this check takes place before the queue
is released and configured again in case of reconfiguration.
That leads to checking against the old configuration and
preventing the shared Rx queue to start properly.

Release the old configuration and prepare a new Rx queue
before checking that its parameters match the config.

Fixes: 09c2555303 ("net/mlx5: support shared Rx queue")

Signed-off-by: Alexander Kozyrev <akozyrev at nvidia.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index b7818f9598..0d9d11680b 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -902,16 +902,20 @@ mlx5_rx_queue_setup(struct rte_eth_dev *dev, uint16_t idx, uint16_t desc,
 		/* Try to reuse shared RXQ. */
 		rxq_ctrl = mlx5_shared_rxq_get(dev, conf->share_group,
 					       conf->share_qid);
+		res = mlx5_rx_queue_pre_setup(dev, idx, &desc, &rxq_ctrl);
+		if (res)
+			return res;
 		if (rxq_ctrl != NULL &&
 		    !mlx5_shared_rxq_match(rxq_ctrl, dev, idx, desc, socket,
 					   conf, mp)) {
 			rte_errno = EINVAL;
 			return -rte_errno;
 		}
+	} else {
+		res = mlx5_rx_queue_pre_setup(dev, idx, &desc, &rxq_ctrl);
+		if (res)
+			return res;
 	}
-	res = mlx5_rx_queue_pre_setup(dev, idx, &desc, &rxq_ctrl);
-	if (res)
-		return res;
 	/* Allocate RXQ. */
 	rxq = mlx5_malloc(MLX5_MEM_RTE | MLX5_MEM_ZERO, sizeof(*rxq), 0,
 			  SOCKET_ID_ANY);
-- 
2.18.2