[dpdk-dev] [PATCH 6/8] net/bnxt: disallow MTU change when device is started

[Kalesh A P]

From: Damodharam Ammepalli <damodharam.ammep...@broadcom.com>

With this patch, bnxt_mtu_set_op() will return an error code if the
device has already started. The user application will have to take
care to bring down device before invoking the mtu_set()

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

Signed-off-by: Damodharam Ammepalli <damodharam.ammep...@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospoda...@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khapa...@broadcom.com>
---
 drivers/net/bnxt/bnxt_ethdev.c | 28 ++++++++--------------------
 1 file changed, 8 insertions(+), 20 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 4e4791c..f040cdc 100644
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -3019,9 +3019,7 @@ bnxt_tx_burst_mode_get(struct rte_eth_dev *dev, 
__rte_unused uint16_t queue_id,
 
 int bnxt_mtu_set_op(struct rte_eth_dev *eth_dev, uint16_t new_mtu)
 {
-       uint32_t overhead = BNXT_MAX_PKT_LEN - BNXT_MAX_MTU;
        struct bnxt *bp = eth_dev->data->dev_private;
-       uint32_t new_pkt_size;
        uint32_t rc;
        uint32_t i;
 
@@ -3029,25 +3027,15 @@ int bnxt_mtu_set_op(struct rte_eth_dev *eth_dev, 
uint16_t new_mtu)
        if (rc)
                return rc;
 
+       /* Return if port is active */
+       if (eth_dev->data->dev_started) {
+               PMD_DRV_LOG(ERR, "Stop port before changing MTU\n");
+               return -EPERM;
+       }
+
        /* Exit if receive queues are not configured yet */
        if (!eth_dev->data->nb_rx_queues)
-               return rc;
-
-       new_pkt_size = new_mtu + overhead;
-
-       /*
-        * Disallow any MTU change that would require scattered receive support
-        * if it is not already enabled.
-        */
-       if (eth_dev->data->dev_started &&
-           !eth_dev->data->scattered_rx &&
-           (new_pkt_size >
-            eth_dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM)) {
-               PMD_DRV_LOG(ERR,
-                           "MTU change would require scattered rx support. ");
-               PMD_DRV_LOG(ERR, "Stop port before changing MTU.\n");
-               return -EINVAL;
-       }
+               return -ENOTSUP;
 
        if (new_mtu > RTE_ETHER_MTU)
                bp->flags |= BNXT_FLAG_JUMBO;
@@ -3056,7 +3044,7 @@ int bnxt_mtu_set_op(struct rte_eth_dev *eth_dev, uint16_t 
new_mtu)
 
        /* Is there a change in mtu setting? */
        if (eth_dev->data->mtu == new_mtu)
-               return rc;
+               return 0;
 
        for (i = 0; i < bp->nr_vnics; i++) {
                struct bnxt_vnic_info *vnic = &bp->vnic_info[i];
-- 
2.10.1