cns3xxx: fix ethernet driver tx completion and queue stop/start

SVN-Revision: 33504

diff --git a/target/linux/cns3xxx/patches-3.3/430-ethernet_fix_tx_completion.patch b/target/linux/cns3xxx/patches-3.3/430-ethernet_fix_tx_completion.patch
new file mode 100644 (file)
index 0000000..9a16c99
--- /dev/null
+++ b/target/linux/cns3xxx/patches-3.3/430-ethernet_fix_tx_completion.patch
@@ -0,0 +1,110 @@
+--- a/drivers/net/ethernet/cavium/cns3xxx_eth.c
++++ b/drivers/net/ethernet/cavium/cns3xxx_eth.c
+@@ -28,6 +28,7 @@
+ 
+ #define RX_DESCS 128
+ #define TX_DESCS 128
++#define TX_DESC_RESERVE       20
+ 
+ #define RX_POOL_ALLOC_SIZE (sizeof(struct rx_desc) * RX_DESCS)
+ #define TX_POOL_ALLOC_SIZE (sizeof(struct tx_desc) * TX_DESCS)
+@@ -266,6 +267,7 @@ struct _tx_ring {
+       u32 cur_index;
+       int num_used;
+       int num_count;
++      bool stopped;
+ };
+ 
+ struct _rx_ring {
+@@ -546,7 +548,34 @@ out:
+       rx_ring->alloc_index = i;
+ }
+ 
+-static void clear_tx_desc(struct sw *sw)
++static void eth_check_num_used(struct _tx_ring *tx_ring)
++{
++      bool stop = false;
++      int i;
++
++      if (tx_ring->num_used >= TX_DESCS - TX_DESC_RESERVE)
++              stop = true;
++
++      if (tx_ring->stopped == stop)
++              return;
++
++      tx_ring->stopped = stop;
++      for (i = 0; i < 4; i++) {
++              struct port *port = switch_port_tab[i];
++              struct net_device *dev;
++
++              if (!port)
++                      continue;
++
++              dev = port->netdev;
++              if (stop)
++                      netif_stop_queue(dev);
++              else
++                      netif_wake_queue(dev);
++      }
++}
++
++static void eth_complete_tx(struct sw *sw)
+ {
+       struct _tx_ring *tx_ring = sw->tx_ring;
+       struct tx_desc *desc;
+@@ -555,9 +584,6 @@ static void clear_tx_desc(struct sw *sw)
+       int num_used = tx_ring->num_used;
+       struct sk_buff *skb;
+ 
+-      if (num_used < (TX_DESCS >> 1))
+-              return;
+-
+       index = tx_ring->free_index;
+       desc = &(tx_ring)->desc[index];
+       for (i = 0; i < num_used; i++) {
+@@ -580,6 +606,7 @@ static void clear_tx_desc(struct sw *sw)
+       }
+       tx_ring->free_index = index;
+       tx_ring->num_used -= i;
++      eth_check_num_used(tx_ring);
+ }
+ 
+ static int eth_poll(struct napi_struct *napi, int budget)
+@@ -688,6 +715,10 @@ static int eth_poll(struct napi_struct *
+ 
+       enable_rx_dma(sw);
+ 
++      spin_lock_bh(&tx_lock);
++      eth_complete_tx(sw);
++      spin_unlock_bh(&tx_lock);
++
+       return received;
+ }
+ 
+@@ -732,21 +763,19 @@ static int eth_xmit(struct sk_buff *skb,
+       skb_walk_frags(skb, skb1)
+               nr_desc++;
+ 
+-      spin_lock(&tx_lock);
++      spin_lock_bh(&tx_lock);
+ 
++      eth_complete_tx(sw);
+       if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
+-              clear_tx_desc(sw);
+-              if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
+-                      spin_unlock(&tx_lock);
+-                      return NETDEV_TX_BUSY;
+-              }
++              spin_unlock_bh(&tx_lock);
++              return NETDEV_TX_BUSY;
+       }
+ 
+       index = index0 = tx_ring->cur_index;
+       index_last = (index0 + nr_desc) % TX_DESCS;
+       tx_ring->cur_index = (index_last + 1) % TX_DESCS;
+ 
+-      spin_unlock(&tx_lock);
++      spin_unlock_bh(&tx_lock);
+ 
+       config0 = FORCE_ROUTE;
+       if (skb->ip_summed == CHECKSUM_PARTIAL)