[dpdk-dev] [PATCH] net/mlx5: fix handling of small mbuf sizes

[Raslan Darawsheh]

When mbufs are smaller than MRU, multi-segment support must be enabled to
default set when not in promiscuous or allmulticast modes.

Fixes: 9964b965ad69 ("net/mlx5: re-add Rx scatter support")

Signed-off-by: Raslan Darawsheh <rasland at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 4dc5cc3..62253ed 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -946,6 +946,12 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl *rxq_ctrl,
 	(void)conf; /* Thresholds configuration (ignored). */
 	/* Enable scattered packets support for this queue if necessary. */
 	assert(mb_len >= RTE_PKTMBUF_HEADROOM);
+	/* If smaller than MRU, multi-segment support must be enabled. */
+	if (mb_len < (priv->mtu > dev->data->dev_conf.rxmode.max_rx_pkt_len ?
+		     dev->data->dev_conf.rxmode.max_rx_pkt_len :
+		     priv->mtu
+		     ))
+		dev->data->dev_conf.rxmode.jumbo_frame = 1;
 	if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
 	    (dev->data->dev_conf.rxmode.max_rx_pkt_len >
 	     (mb_len - RTE_PKTMBUF_HEADROOM))) {
-- 
1.9.1