[dpdk-dev] [PATCH] net/mlx5: change calculating inline room for Tx

[Yongseok Koh]

Current implementation is error-prone if the max inline size
(txq->max_inilne) is decoupled from txq->inline_en and becomes zero. If it
becomes zero, HW can crash due to WQ overflow.

Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
Acked-by: Shahaf Shuler <shahafs at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 2e208bf96..6254228a9 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -499,6 +499,8 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 	unsigned int j = 0;
 	unsigned int k = 0;
 	unsigned int max;
+	unsigned int max_inline = txq->max_inline;
+	const unsigned int inline_en = !!max_inline && txq->inline_en;
 	uint16_t max_wqe;
 	unsigned int comp;
 	volatile struct mlx5_wqe_v *wqe = NULL;
@@ -685,14 +687,14 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			}
 		}
 		/* Inline if enough room. */
-		if (txq->inline_en || tso) {
+		if (inline_en || tso) {
 			uintptr_t end = (uintptr_t)
 				(((uintptr_t)txq->wqes) +
 				 (1 << txq->wqe_n) * MLX5_WQE_SIZE);
-			unsigned int max_inline = txq->max_inline *
-						  RTE_CACHE_LINE_SIZE -
-						  (pkt_inline_sz - 2);
-			uintptr_t addr_end = (addr + max_inline) &
+			unsigned int inline_room = max_inline *
+						   RTE_CACHE_LINE_SIZE -
+						   (pkt_inline_sz - 2);
+			uintptr_t addr_end = (addr + inline_room) &
 					     ~(RTE_CACHE_LINE_SIZE - 1);
 			unsigned int copy_b = (addr_end > addr) ?
 				RTE_MIN((addr_end - addr), length) :
-- 
2.11.0