From: Rob Herring Date: Fri, 30 Aug 2013 21:49:23 +0000 (-0500) Subject: net: calxedaxgmac: update ring buffer tx_head after barriers X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=ca32723afedd65d612029705446bf44bde5eab14;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git 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 Signed-off-by: Rob Herring Signed-off-by: David S. Miller --- 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);