[PATCH net-next 3/4] net: hns3: fix for cleaning ring problem

[Salil Mehta]

From: Yunsheng Lin <linyunsh...@huawei.com>

The head or tail in hardware is not longer valid when resetting,
current hns3_clear_all_ring use them to clean the ring, which
will cause problem during resetting.

This patch fixes it by using next_to_use and next_to_clean in
the ring struct.

Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 
SoC")
Signed-off-by: Yunsheng Lin <linyunsh...@huawei.com>
Signed-off-by: Peng Li <lipeng...@huawei.com>
Signed-off-by: Salil Mehta <salil.me...@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 34 ++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c 
b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index bd8e14b..4031174 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -3203,9 +3203,35 @@ static void hns3_recover_hw_addr(struct net_device *ndev)
                hns3_nic_mc_sync(ndev, ha->addr);
 }
 
-static void hns3_drop_skb_data(struct hns3_enet_ring *ring, struct sk_buff 
*skb)
+static void hns3_clear_tx_ring(struct hns3_enet_ring *ring)
 {
-       dev_kfree_skb_any(skb);
+       if (!HNAE3_IS_TX_RING(ring))
+               return;
+
+       while (ring->next_to_clean != ring->next_to_use) {
+               hns3_free_buffer_detach(ring, ring->next_to_clean);
+               ring_ptr_move_fw(ring, next_to_clean);
+       }
+}
+
+static void hns3_clear_rx_ring(struct hns3_enet_ring *ring)
+{
+       if (HNAE3_IS_TX_RING(ring))
+               return;
+
+       while (ring->next_to_use != ring->next_to_clean) {
+               /* When a buffer is not reused, it's memory has been
+                * freed in hns3_handle_rx_bd or will be freed by
+                * stack, so only need to unmap the buffer here.
+                */
+               if (!ring->desc_cb[ring->next_to_use].reuse_flag) {
+                       hns3_unmap_buffer(ring,
+                                         &ring->desc_cb[ring->next_to_use]);
+                       ring->desc_cb[ring->next_to_use].dma = 0;
+               }
+
+               ring_ptr_move_fw(ring, next_to_use);
+       }
 }
 
 static void hns3_clear_all_ring(struct hnae3_handle *h)
@@ -3219,13 +3245,13 @@ static void hns3_clear_all_ring(struct hnae3_handle *h)
                struct hns3_enet_ring *ring;
 
                ring = priv->ring_data[i].ring;
-               hns3_clean_tx_ring(ring, ring->desc_num);
+               hns3_clear_tx_ring(ring);
                dev_queue = netdev_get_tx_queue(ndev,
                                                priv->ring_data[i].queue_index);
                netdev_tx_reset_queue(dev_queue);
 
                ring = priv->ring_data[i + h->kinfo.num_tqps].ring;
-               hns3_clean_rx_ring(ring, ring->desc_num, hns3_drop_skb_data);
+               hns3_clear_rx_ring(ring);
        }
 }
 
-- 
2.7.4