[PATCH v3 06/14] net/cnxk: fix issue with buff size compute

[Nithin Dabilpuram]

In case where cnxk_nix_mtu_set() is called before
data->min_rx_buf_size is set, use buf size from first RQ's
mempool.

Fixes: 34b46320f446 ("net/cnxk: perform early MTU setup for event mode")
Cc: sta...@dpdk.org

Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com>
---
 drivers/net/cnxk/cnxk_ethdev_ops.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/net/cnxk/cnxk_ethdev_ops.c 
b/drivers/net/cnxk/cnxk_ethdev_ops.c
index e9ab8da781..e816884d47 100644
--- a/drivers/net/cnxk/cnxk_ethdev_ops.c
+++ b/drivers/net/cnxk/cnxk_ethdev_ops.c
@@ -544,8 +544,9 @@ cnxk_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
        struct cnxk_eth_dev *dev = cnxk_eth_pmd_priv(eth_dev);
        struct rte_eth_dev_data *data = eth_dev->data;
        struct roc_nix *nix = &dev->nix;
+       struct cnxk_eth_rxq_sp *rxq_sp;
+       uint32_t buffsz = 0;
        int rc = -EINVAL;
-       uint32_t buffsz;
 
        frame_size += CNXK_NIX_TIMESYNC_RX_OFFSET * dev->ptp_en;
 
@@ -561,8 +562,24 @@ cnxk_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
                goto exit;
        }
 
-       buffsz = data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM;
-       old_frame_size = data->mtu + CNXK_NIX_L2_OVERHEAD;
+       if (!eth_dev->data->nb_rx_queues)
+               goto skip_buffsz_check;
+
+       /* Perform buff size check */
+       if (data->min_rx_buf_size) {
+               buffsz = data->min_rx_buf_size;
+       } else if (eth_dev->data->rx_queues && eth_dev->data->rx_queues[0]) {
+               rxq_sp = cnxk_eth_rxq_to_sp(data->rx_queues[0]);
+
+               if (rxq_sp->qconf.mp)
+                       buffsz = rte_pktmbuf_data_room_size(rxq_sp->qconf.mp);
+       }
+
+       /* Skip validation if RQ's are not yet setup */
+       if (!buffsz)
+               goto skip_buffsz_check;
+
+       buffsz -= RTE_PKTMBUF_HEADROOM;
 
        /* Refuse MTU that requires the support of scattered packets
         * when this feature has not been enabled before.
@@ -580,6 +597,8 @@ cnxk_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
                goto exit;
        }
 
+skip_buffsz_check:
+       old_frame_size = data->mtu + CNXK_NIX_L2_OVERHEAD;
        /* if new MTU was smaller than old one, then flush all SQs before MTU 
change */
        if (old_frame_size > frame_size) {
                if (data->dev_started) {
-- 
2.25.1