[dpdk-dev] [PATCH v2 2/2] examples/kni: fix MTU change to setup Tx queue

[Rasesh Mody]

This patch adds a fix to setup Tx queue when changing KNI interface MTU.
It ensures device can safely start txq post MTU change operation.

Fixes: fc9ee41b7016 ("examples/kni: convert to new ethdev offloads API")
Cc: sta...@dpdk.org

Signed-off-by: Rasesh Mody <rm...@marvell.com>
---
 examples/kni/main.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/examples/kni/main.c b/examples/kni/main.c
index 6b4ab3b5b..7a927a50c 100644
--- a/examples/kni/main.c
+++ b/examples/kni/main.c
@@ -774,9 +774,11 @@ kni_change_mtu(uint16_t port_id, unsigned int new_mtu)
 {
        int ret;
        uint16_t nb_rxd = NB_RXD;
+       uint16_t nb_txd = NB_TXD;
        struct rte_eth_conf conf;
        struct rte_eth_dev_info dev_info;
        struct rte_eth_rxconf rxq_conf;
+       struct rte_eth_txconf txq_conf;
 
        if (!rte_eth_dev_is_valid_port(port_id)) {
                RTE_LOG(ERR, APP, "Invalid port id %d\n", port_id);
@@ -804,7 +806,7 @@ kni_change_mtu(uint16_t port_id, unsigned int new_mtu)
                return ret;
        }
 
-       ret = rte_eth_dev_adjust_nb_rx_tx_desc(port_id, &nb_rxd, NULL);
+       ret = rte_eth_dev_adjust_nb_rx_tx_desc(port_id, &nb_rxd, &nb_txd);
        if (ret < 0)
                rte_exit(EXIT_FAILURE, "Could not adjust number of descriptors "
                                "for port%u (%d)\n", (unsigned int)port_id,
@@ -829,6 +831,16 @@ kni_change_mtu(uint16_t port_id, unsigned int new_mtu)
                return ret;
        }
 
+       txq_conf = dev_info.default_txconf;
+       txq_conf.offloads = conf.txmode.offloads;
+       ret = rte_eth_tx_queue_setup(port_id, 0, nb_txd,
+               rte_eth_dev_socket_id(port_id), &txq_conf);
+       if (ret < 0) {
+               RTE_LOG(ERR, APP, "Fail to setup Tx queue of port %d\n",
+                               port_id);
+               return ret;
+       }
+
        /* Restart specific port */
        ret = rte_eth_dev_start(port_id);
        if (ret < 0) {
-- 
2.18.0