netdev: octeon_mgmt: Try not to drop TX packets when stopping the queue.

Stop the queue when we add the packet that will fill it instead of dropping the packet

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/net/octeon/octeon_mgmt.c b/drivers/net/octeon/octeon_mgmt.c
index 3cf6f62502c8..1fdc7b303a6b 100644
--- a/drivers/net/octeon/octeon_mgmt.c
+++ b/drivers/net/octeon/octeon_mgmt.c
@@ -955,6 +955,7 @@ static int octeon_mgmt_xmit(struct sk_buff *skb, struct net_device *netdev)
         int port = p->port;
         union mgmt_port_ring_entry re;
         unsigned long flags;
+        int rv = NETDEV_TX_BUSY;
 
         re.d64 = 0;
         re.s.len = skb->len;
@@ -964,15 +965,18 @@ static int octeon_mgmt_xmit(struct sk_buff *skb, struct net_device *netdev)
 
         spin_lock_irqsave(&p->tx_list.lock, flags);
 
+        if (unlikely(p->tx_current_fill >= ring_max_fill(OCTEON_MGMT_TX_RING_SIZE) - 1)) {
+                spin_unlock_irqrestore(&p->tx_list.lock, flags);
+                netif_stop_queue(netdev);
+                spin_lock_irqsave(&p->tx_list.lock, flags);
+        }
+
         if (unlikely(p->tx_current_fill >=
                      ring_max_fill(OCTEON_MGMT_TX_RING_SIZE))) {
                 spin_unlock_irqrestore(&p->tx_list.lock, flags);
-
                 dma_unmap_single(p->dev, re.s.addr, re.s.len,
                                  DMA_TO_DEVICE);
-
-                netif_stop_queue(netdev);
-                return NETDEV_TX_BUSY;
+                goto out;
         }
 
         __skb_queue_tail(&p->tx_list, skb);
@@ -995,8 +999,10 @@ static int octeon_mgmt_xmit(struct sk_buff *skb, struct net_device *netdev)
         cvmx_write_csr(CVMX_MIXX_ORING2(port), 1);
 
         netdev->trans_start = jiffies;
+        rv = NETDEV_TX_OK;
+out:
         octeon_mgmt_update_tx_stats(netdev);
-        return NETDEV_TX_OK;
+        return rv;
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER