bnxt_en: stop packet flow during bnxt_queue_stop/start

The current implementation when resetting a queue while packets are
flowing puts the queue into an inconsistent state.

There needs to be some synchronisation with the FW. Add calls to
bnxt_hwrm_vnic_update() to set the MRU for both the default and ntuple
vnic during queue start/stop. When the MRU is set to 0, flow is stopped.
Each Rx queue belongs to either the default or the ntuple vnic.

With calling bnxt_hwrm_vnic_update() the calls to napi_enable() and
napi_disable() must be removed for reset to work on a queue that has
active traffic flowing e.g. iperf3.

Co-developed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -15177,7 +15177,8 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 	struct bnxt *bp = netdev_priv(dev);
 	struct bnxt_rx_ring_info *rxr, *clone;
 	struct bnxt_cp_ring_info *cpr;
-	int rc;
+	struct bnxt_vnic_info *vnic;
+	int i, rc;
 
 	rxr = &bp->rx_ring[idx];
 	clone = qmem;
@@ -15202,11 +15203,16 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 	if (bp->flags & BNXT_FLAG_AGG_RINGS)
 		bnxt_db_write(bp, &rxr->rx_agg_db, rxr->rx_agg_prod);
 
-	napi_enable(&rxr->bnapi->napi);
-
 	cpr = &rxr->bnapi->cp_ring;
 	cpr->sw_stats->rx.rx_resets++;
 
+	for (i = 0; i <= BNXT_VNIC_NTUPLE; i++) {
+		vnic = &bp->vnic_info[i];
+		vnic->mru = bp->dev->mtu + ETH_HLEN + VLAN_HLEN;
+		bnxt_hwrm_vnic_update(bp, vnic,
+				      VNIC_UPDATE_REQ_ENABLES_MRU_VALID);
+	}
+
 	return 0;
 
 err_free_hwrm_rx_ring:
@@ -15218,9 +15224,17 @@ static int bnxt_queue_stop(struct net_device *dev, void *qmem, int idx)
 {
 	struct bnxt *bp = netdev_priv(dev);
 	struct bnxt_rx_ring_info *rxr;
+	struct bnxt_vnic_info *vnic;
+	int i;
+
+	for (i = 0; i <= BNXT_VNIC_NTUPLE; i++) {
+		vnic = &bp->vnic_info[i];
+		vnic->mru = 0;
+		bnxt_hwrm_vnic_update(bp, vnic,
+				      VNIC_UPDATE_REQ_ENABLES_MRU_VALID);
+	}
 
 	rxr = &bp->rx_ring[idx];
-	napi_disable(&rxr->bnapi->napi);
 	bnxt_hwrm_rx_ring_free(bp, rxr, false);
 	bnxt_hwrm_rx_agg_ring_free(bp, rxr, false);
 	rxr->rx_next_cons = 0;