be2net: fix rx-path to ignore a flush completion

The flush compl (compl with numfrags == 0; no data) is rcvd
from hw to indicate completion of RXQ destory operation. Fix
the RX path to not process it as RX data.
Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/benet/be_main.c

@@ -680,17 +680,17 @@ static void be_rx_compl_discard(struct be_adapter *adapter,
  * indicated by rxcp.
  */
 static void skb_fill_rx_data(struct be_adapter *adapter,
-			struct sk_buff *skb, struct be_eth_rx_compl *rxcp)
+			struct sk_buff *skb, struct be_eth_rx_compl *rxcp,
+			u16 num_rcvd)
 {
 	struct be_queue_info *rxq = &adapter->rx_obj.q;
 	struct be_rx_page_info *page_info;
-	u16 rxq_idx, i, num_rcvd, j;
+	u16 rxq_idx, i, j;
 	u32 pktsize, hdr_len, curr_frag_len, size;
 	u8 *start;
 
 	rxq_idx = AMAP_GET_BITS(struct amap_eth_rx_compl, fragndx, rxcp);
 	pktsize = AMAP_GET_BITS(struct amap_eth_rx_compl, pktsize, rxcp);
-	num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
 
 	page_info = get_rx_page_info(adapter, rxq_idx);
 
@@ -766,8 +766,14 @@ static void be_rx_compl_process(struct be_adapter *adapter,
 {
 	struct sk_buff *skb;
 	u32 vlanf, vid;
+	u16 num_rcvd;
 	u8 vtm;
 
+	num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
+	/* Is it a flush compl that has no data */
+	if (unlikely(num_rcvd == 0))
+		return;
+
 	skb = netdev_alloc_skb_ip_align(adapter->netdev, BE_HDR_LEN);
 	if (unlikely(!skb)) {
 		if (net_ratelimit())
@@ -776,7 +782,7 @@ static void be_rx_compl_process(struct be_adapter *adapter,
 		return;
 	}
 
-	skb_fill_rx_data(adapter, skb, rxcp);
+	skb_fill_rx_data(adapter, skb, rxcp, num_rcvd);
 
 	if (do_pkt_csum(rxcp, adapter->rx_csum))
 		skb->ip_summed = CHECKSUM_NONE;
@@ -823,6 +829,10 @@ static void be_rx_compl_process_gro(struct be_adapter *adapter,
 	u8 vtm;
 
 	num_rcvd = AMAP_GET_BITS(struct amap_eth_rx_compl, numfrags, rxcp);
+	/* Is it a flush compl that has no data */
+	if (unlikely(num_rcvd == 0))
+		return;
+
 	pkt_size = AMAP_GET_BITS(struct amap_eth_rx_compl, pktsize, rxcp);
 	vlanf = AMAP_GET_BITS(struct amap_eth_rx_compl, vtp, rxcp);
 	rxq_idx = AMAP_GET_BITS(struct amap_eth_rx_compl, fragndx, rxcp);
@@ -1273,6 +1283,11 @@ static void be_rx_queues_destroy(struct be_adapter *adapter)
 	q = &adapter->rx_obj.q;
 	if (q->created) {
 		be_cmd_q_destroy(adapter, q, QTYPE_RXQ);
+
+		/* After the rxq is invalidated, wait for a grace time
+		 * of 1ms for all dma to end and the flush compl to arrive
+		 */
+		mdelay(1);
 		be_rx_q_clean(adapter);
 	}
 	be_queue_free(adapter, q);