diff options
| -rw-r--r-- | drivers/net/ethernet/calxeda/xgmac.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c index f63085571241..5d0b61a5c72b 100644 --- a/drivers/net/ethernet/calxeda/xgmac.c +++ b/drivers/net/ethernet/calxeda/xgmac.c @@ -410,6 +410,9 @@ struct xgmac_priv { #define dma_ring_space(h, t, s) CIRC_SPACE(h, t, s) #define dma_ring_cnt(h, t, s) CIRC_CNT(h, t, s) +#define tx_dma_ring_space(p) \ + dma_ring_space((p)->tx_head, (p)->tx_tail, DMA_TX_RING_SZ) + /* XGMAC Descriptor Access Helpers */ static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz) { @@ -886,8 +889,10 @@ static void xgmac_tx_complete(struct xgmac_priv *priv) priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ); } - if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) > - MAX_SKB_FRAGS) + /* Ensure tx_tail is visible to xgmac_xmit */ + smp_mb(); + if (unlikely(netif_queue_stopped(priv->dev) && + (tx_dma_ring_space(priv) > MAX_SKB_FRAGS))) netif_wake_queue(priv->dev); } @@ -1125,10 +1130,15 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev) priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ); - if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) < - MAX_SKB_FRAGS) + /* Ensure tx_head update is visible to tx completion */ + smp_mb(); + if (unlikely(tx_dma_ring_space(priv) <= MAX_SKB_FRAGS)) { netif_stop_queue(dev); - + /* Ensure netif_stop_queue is visible to tx completion */ + smp_mb(); + if (tx_dma_ring_space(priv) > MAX_SKB_FRAGS) + netif_start_queue(dev); + } return NETDEV_TX_OK; } |