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authorRob Herring <rob.herring@calxeda.com>2013-08-30 23:49:23 +0200
committerDavid S. Miller <davem@davemloft.net>2013-09-04 04:21:15 +0200
commitca32723afedd65d612029705446bf44bde5eab14 (patch)
treeab65afe5d86f42a087990bce3b94f36470ac58b6 /drivers/net/ethernet/calxeda
parentnet: calxedaxgmac: fix possible skb free before tx complete (diff)
downloadlinux-ca32723afedd65d612029705446bf44bde5eab14.tar.xz
linux-ca32723afedd65d612029705446bf44bde5eab14.zip
net: calxedaxgmac: update ring buffer tx_head after barriers
Ensure that the descriptor writes are visible before the ring buffer head is updated. Since writel is a barrier, we can simply update the head after the writel. Reported-by: Lennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/calxeda')
-rw-r--r--drivers/net/ethernet/calxeda/xgmac.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 64854ad84b55..f63085571241 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1121,9 +1121,10 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
wmb();
desc_set_tx_owner(first, desc_flags | TXDESC_FIRST_SEG);
+ writel(1, priv->base + XGMAC_DMA_TX_POLL);
+
priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);
- writel(1, priv->base + XGMAC_DMA_TX_POLL);
if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) <
MAX_SKB_FRAGS)
netif_stop_queue(dev);