net: mana: Add handling of CQE_RX_TRUNCATED

The proper way to drop this kind of CQE is advancing rxq tail
without indicating the packet to the upper network layer.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microsoft/mana/mana_en.c

@@ -1085,8 +1085,10 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 		break;
 
 	case CQE_RX_TRUNCATED:
-		netdev_err(ndev, "Dropped a truncated packet\n");
-		return;
+		++ndev->stats.rx_dropped;
+		rxbuf_oob = &rxq->rx_oobs[rxq->buf_index];
+		netdev_warn_once(ndev, "Dropped a truncated packet\n");
+		goto drop;
 
 	case CQE_RX_COALESCED_4:
 		netdev_err(ndev, "RX coalescing is unsupported\n");
@@ -1154,6 +1156,7 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 
 	mana_rx_skb(old_buf, oob, rxq);
 
+drop:
 	mana_move_wq_tail(rxq->gdma_rq, rxbuf_oob->wqe_inf.wqe_size_in_bu);
 
 	mana_post_pkt_rxq(rxq);