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 7166288..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
@@ -436,14 +436,20 @@ static void cns3xxx_adjust_link(struct net_device *dev)
               dev->name, port->speed, port->duplex ? "full" : "half");
 }
 
+static void eth_schedule_poll(struct sw *sw)
+{
+       if (unlikely(!napi_schedule_prep(&sw->napi)))
+               return;
+
+       disable_irq_nosync(IRQ_CNS3XXX_SW_R0RXC);
+       __napi_schedule(&sw->napi);
+}
+
 irqreturn_t eth_rx_irq(int irq, void *pdev)
 {
        struct net_device *dev = pdev;
        struct sw *sw = netdev_priv(dev);
-       if (likely(napi_schedule_prep(&sw->napi))) {
-               disable_irq_nosync(IRQ_CNS3XXX_SW_R0RXC);
-               __napi_schedule(&sw->napi);
-       }
+       eth_schedule_poll(sw);
        return (IRQ_HANDLED);
 }
 
@@ -577,7 +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;
@@ -609,6 +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)
@@ -707,22 +715,25 @@ 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);
        }
 
-       cns3xxx_alloc_rx_buf(sw, received);
+       spin_lock_bh(&tx_lock);
+       eth_complete_tx(sw);
+       spin_unlock_bh(&tx_lock);
 
-       rx_ring->cur_index = i;
+       cns3xxx_alloc_rx_buf(sw, received);
 
        wmb();
        enable_rx_dma(sw);
 
-       spin_lock_bh(&tx_lock);
-       eth_complete_tx(sw);
-       spin_unlock_bh(&tx_lock);
-
        return received;
 }
 
@@ -768,11 +779,12 @@ static int eth_xmit(struct sk_buff *skb, struct net_device *dev)
                nr_desc++;
 
        spin_lock_bh(&tx_lock);
-
-       eth_complete_tx(sw);
        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;