cns3xxx: ethernet - clean up tx descs only when needed

[openwrt.git] / target / linux / cns3xxx / files / drivers / net / ethernet / cavium / cns3xxx_eth.c

diff --git a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
index db15a2e..9692d47 100644 (file)
--- a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
+++ b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
@@ -583,7 +583,7 @@ static void eth_check_num_used(struct _tx_ring *tx_ring)
        }
 }
 
-static void eth_complete_tx(struct sw *sw)
+static int eth_complete_tx(struct sw *sw)
 {
        struct _tx_ring *tx_ring = &sw->tx_ring;
        struct tx_desc *desc;
@@ -615,6 +615,8 @@ static void eth_complete_tx(struct sw *sw)
        tx_ring->free_index = index;
        tx_ring->num_used -= i;
        eth_check_num_used(tx_ring);
+
+       return TX_DESCS - tx_ring->num_used;
 }
 
 static int eth_poll(struct napi_struct *napi, int budget)
@@ -713,9 +715,14 @@ static int eth_poll(struct napi_struct *napi, int budget)
                }
        }
 
+       rx_ring->cur_index = i;
        if (!received) {
                napi_complete(napi);
                enable_irq(IRQ_CNS3XXX_SW_R0RXC);
+
+               /* if rx descriptors are full schedule another poll */
+               if (rx_ring->desc[(i-1) & (RX_DESCS-1)].cown)
+                       eth_schedule_poll(sw);
        }
 
        spin_lock_bh(&tx_lock);
@@ -724,8 +731,6 @@ static int eth_poll(struct napi_struct *napi, int budget)
 
        cns3xxx_alloc_rx_buf(sw, received);
 
-       rx_ring->cur_index = i;
-
        wmb();
        enable_rx_dma(sw);
 
@@ -773,11 +778,13 @@ static int eth_xmit(struct sk_buff *skb, struct net_device *dev)
        skb_walk_frags(skb, skb1)
                nr_desc++;
 
-       eth_schedule_poll(sw);
        spin_lock_bh(&tx_lock);
        if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
-               spin_unlock_bh(&tx_lock);
-               return NETDEV_TX_BUSY;
+               /* clean up tx descriptors when needed */
+               if (eth_complete_tx(sw) < nr_desc) {
+                       spin_unlock_bh(&tx_lock);
+                       return NETDEV_TX_BUSY;
+               }
        }
 
        index = index0 = tx_ring->cur_index;