net: hns: delete repeat read fbd num after while

Because we handle the received packets after napi, so delete the checking
before submitting. It delete the code of read the fbd number register,
which reduces the cpu usages while receiving packets
Signed-off-by: NDaode Huang <huangdaode@hisilicon.com>
Reviewed-by: NYisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: NSalil Mehta <salil.mehta@huawei.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/net/ethernet/hisilicon/hns/hns_enet.c

@@ -760,7 +760,7 @@ static int hns_nic_rx_poll_one(struct hns_nic_ring_data *ring_data,
 {
 	struct hnae_ring *ring = ring_data->ring;
 	struct sk_buff *skb;
-	int num, bnum, ex_num;
+	int num, bnum;
 #define RCB_NOF_ALLOC_RX_BUFF_ONCE 16
 	int recv_pkts, recv_bds, clean_count, err;
 	int unused_count = hns_desc_unused(ring);
@@ -770,7 +770,7 @@ static int hns_nic_rx_poll_one(struct hns_nic_ring_data *ring_data,
 
 	recv_pkts = 0, recv_bds = 0, clean_count = 0;
 	num -= unused_count;
-recv:
+
 	while (recv_pkts < budget && recv_bds < num) {
 		/* reuse or realloc buffers */
 		if (clean_count + unused_count >= RCB_NOF_ALLOC_RX_BUFF_ONCE) {
@@ -798,17 +798,6 @@ static int hns_nic_rx_poll_one(struct hns_nic_ring_data *ring_data,
 		recv_pkts++;
 	}
 
-	/* make all data has been write before submit */
-	if (recv_pkts < budget) {
-		ex_num = readl_relaxed(ring->io_base + RCB_REG_FBDNUM);
-		ex_num -= unused_count;
-		if (ex_num > clean_count) {
-			num += ex_num - clean_count;
-			rmb(); /*complete read rx ring bd number*/
-			goto recv;
-		}
-	}
-
 out:
 	/* make all data has been write before submit */
 	if (clean_count + unused_count > 0)