net/mlx5: fix Tx check for hardware descriptor length

[ upstream commit 130bb7d ]

If hardware descriptor (WQE) length exceeds one the HW can handle,
the Tx queue failure occurs. PMD does the length check but there was
a bug - the length limit was expressed in 16B units (WQEBB segments),
while the calculated WQE length and limit were in 64B units (WQEBBs).
Fix the condition to avoid subsequent Tx queue failure.

Fixes: 18a1c20 ("net/mlx5: implement Tx burst template")

Signed-off-by: Raja Zidane <rzidane@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

drivers/net/mlx5/mlx5_tx.h

@@ -1731,7 +1731,7 @@ mlx5_tx_packet_multi_tso(struct mlx5_txq_data *__rte_restrict txq,
 	if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
 		return MLX5_TXCMP_CODE_EXIT;
 	/* Check for maximal WQE size. */
-	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
+	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ds))
 		return MLX5_TXCMP_CODE_ERROR;
 #ifdef MLX5_PMD_SOFT_COUNTERS
 	/* Update sent data bytes/packets counters. */
@@ -1806,7 +1806,7 @@ mlx5_tx_packet_multi_send(struct mlx5_txq_data *__rte_restrict txq,
 	if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
 		return MLX5_TXCMP_CODE_EXIT;
 	/* Check for maximal WQE size. */
-	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
+	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ds))
 		return MLX5_TXCMP_CODE_ERROR;
 	/*
 	 * Some Tx offloads may cause an error if packet is not long enough,