[PATCH v2] net/mlx5: fix multi segment packet wraparound

[Dariusz Sosnowski]

This patch fixes the assertion failure triggered when the user
configured minimum inline length requirements and the application
transmitted multi segment packets. Failure was triggered when space left
in TX queue was not enough to cover this requirement.

This patch limits the length of data to be copied to the available space
in TX queue.

Fixes: cacb44a09962 ("net/mlx5: add no-inline Tx flag")
Cc: viacheslavo at nvidia.com
Cc: stable at dpdk.org

Signed-off-by: Dariusz Sosnowski <dsosnowski at nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
---
 drivers/net/mlx5/mlx5_tx.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_tx.h b/drivers/net/mlx5/mlx5_tx.h
index bc629983fa..099e72935a 100644
--- a/drivers/net/mlx5/mlx5_tx.h
+++ b/drivers/net/mlx5/mlx5_tx.h
@@ -1071,7 +1071,6 @@ mlx5_tx_mseg_memcpy(uint8_t *pdst,
 	uint8_t *psrc;
 
 	MLX5_ASSERT(len);
-	MLX5_ASSERT(must <= len);
 	do {
 		/* Allow zero length packets, must check first. */
 		dlen = rte_pktmbuf_data_len(loc->mbuf);
@@ -1098,9 +1097,11 @@ mlx5_tx_mseg_memcpy(uint8_t *pdst,
 				if (diff <= rte_pktmbuf_data_len(loc->mbuf)) {
 					/*
 					 * Copy only the minimal required
-					 * part of the data buffer.
+					 * part of the data buffer. Limit amount
+					 * of data to be copied to the length of
+					 * available space.
 					 */
-					len = diff;
+					len = RTE_MIN(len, diff);
 				}
 			}
 			continue;
-- 
2.25.1