target/linux/cns3xxx/patches-3.3/430-ethernet_fix_tx_completion.patch

   1 --- a/drivers/net/ethernet/cavium/cns3xxx_eth.c
   2 +++ b/drivers/net/ethernet/cavium/cns3xxx_eth.c
   3 @@ -28,6 +28,7 @@
   4
   5  #define RX_DESCS 128
   6  #define TX_DESCS 128
   7 +#define TX_DESC_RESERVE        20
   8
   9  #define RX_POOL_ALLOC_SIZE (sizeof(struct rx_desc) * RX_DESCS)
  10  #define TX_POOL_ALLOC_SIZE (sizeof(struct tx_desc) * TX_DESCS)
  11 @@ -266,6 +267,7 @@ struct _tx_ring {
  12         u32 cur_index;
  13         int num_used;
  14         int num_count;
  15 +       bool stopped;
  16  };
  17
  18  struct _rx_ring {
  19 @@ -546,7 +548,34 @@ out:
  20         rx_ring->alloc_index = i;
  21  }
  22
  23 -static void clear_tx_desc(struct sw *sw)
  24 +static void eth_check_num_used(struct _tx_ring *tx_ring)
  25 +{
  26 +       bool stop = false;
  27 +       int i;
  28 +
  29 +       if (tx_ring->num_used >= TX_DESCS - TX_DESC_RESERVE)
  30 +               stop = true;
  31 +
  32 +       if (tx_ring->stopped == stop)
  33 +               return;
  34 +
  35 +       tx_ring->stopped = stop;
  36 +       for (i = 0; i < 4; i++) {
  37 +               struct port *port = switch_port_tab[i];
  38 +               struct net_device *dev;
  39 +
  40 +               if (!port)
  41 +                       continue;
  42 +
  43 +               dev = port->netdev;
  44 +               if (stop)
  45 +                       netif_stop_queue(dev);
  46 +               else
  47 +                       netif_wake_queue(dev);
  48 +       }
  49 +}
  50 +
  51 +static void eth_complete_tx(struct sw *sw)
  52  {
  53         struct _tx_ring *tx_ring = sw->tx_ring;
  54         struct tx_desc *desc;
  55 @@ -555,9 +584,6 @@ static void clear_tx_desc(struct sw *sw)
  56         int num_used = tx_ring->num_used;
  57         struct sk_buff *skb;
  58
  59 -       if (num_used < (TX_DESCS >> 1))
  60 -               return;
  61 -
  62         index = tx_ring->free_index;
  63         desc = &(tx_ring)->desc[index];
  64         for (i = 0; i < num_used; i++) {
  65 @@ -580,6 +606,7 @@ static void clear_tx_desc(struct sw *sw)
  66         }
  67         tx_ring->free_index = index;
  68         tx_ring->num_used -= i;
  69 +       eth_check_num_used(tx_ring);
  70  }
  71
  72  static int eth_poll(struct napi_struct *napi, int budget)
  73 @@ -688,6 +715,10 @@ static int eth_poll(struct napi_struct *
  74
  75         enable_rx_dma(sw);
  76
  77 +       spin_lock_bh(&tx_lock);
  78 +       eth_complete_tx(sw);
  79 +       spin_unlock_bh(&tx_lock);
  80 +
  81         return received;
  82  }
  83
  84 @@ -732,21 +763,19 @@ static int eth_xmit(struct sk_buff *skb,
  85         skb_walk_frags(skb, skb1)
  86                 nr_desc++;
  87
  88 -       spin_lock(&tx_lock);
  89 +       spin_lock_bh(&tx_lock);
  90
  91 +       eth_complete_tx(sw);
  92         if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
  93 -               clear_tx_desc(sw);
  94 -               if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
  95 -                       spin_unlock(&tx_lock);
  96 -                       return NETDEV_TX_BUSY;
  97 -               }
  98 +               spin_unlock_bh(&tx_lock);
  99 +               return NETDEV_TX_BUSY;
 100         }
 101
 102         index = index0 = tx_ring->cur_index;
 103         index_last = (index0 + nr_desc) % TX_DESCS;
 104         tx_ring->cur_index = (index_last + 1) % TX_DESCS;
 105
 106 -       spin_unlock(&tx_lock);
 107 +       spin_unlock_bh(&tx_lock);
 108
 109         config0 = FORCE_ROUTE;
 110         if (skb->ip_summed == CHECKSUM_PARTIAL)