[dpdk-stable] [PATCH 28/31] net/bnxt: fix set MTU

[Ajit Khaparde]

There is no need to update hardware configuration if new MTU is
not greater than the max data the mbuf can accommodate.

Fixes: daef48efe5e5 ("net/bnxt: support set MTU")
Cc: stable at dpdk.org

Signed-off-by: Ajit Khaparde <ajit.khaparde at broadcom.com>
---
 drivers/net/bnxt/bnxt_ethdev.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 9cfa43778..1145bc195 100644
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -1597,6 +1597,7 @@ static int bnxt_mtu_set_op(struct rte_eth_dev *eth_dev, uint16_t new_mtu)
 
 	for (i = 0; i < bp->nr_vnics; i++) {
 		struct bnxt_vnic_info *vnic = &bp->vnic_info[i];
+		uint16_t size = 0;
 
 		vnic->mru = bp->eth_dev->data->mtu + ETHER_HDR_LEN +
 					ETHER_CRC_LEN + VLAN_TAG_SIZE * 2;
@@ -1604,9 +1605,14 @@ static int bnxt_mtu_set_op(struct rte_eth_dev *eth_dev, uint16_t new_mtu)
 		if (rc)
 			break;
 
-		rc = bnxt_hwrm_vnic_plcmode_cfg(bp, vnic);
-		if (rc)
-			return rc;
+		size = rte_pktmbuf_data_room_size(bp->rx_queues[0]->mb_pool);
+		size -= RTE_PKTMBUF_HEADROOM;
+
+		if (size < new_mtu) {
+			rc = bnxt_hwrm_vnic_plcmode_cfg(bp, vnic);
+			if (rc)
+				return rc;
+		}
 	}
 
 	return rc;
-- 
2.15.1 (Apple Git-101)