From 92cd4253e553e87a715243a36623945edcbf1ec7 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Fri, 30 Aug 2013 16:49:29 -0500 Subject: [PATCH] net: calxedaxgmac: fix xgmac_xmit DMA mapping error handling On a DMA mapping error in xgmac_xmit, we should simply free the skb and return NETDEV_TX_OK rather than -EIO. In the case of errors in mapping frags, we need to undo everything that has been setup. Reported-by: Andreas Herrmann Signed-off-by: Rob Herring Signed-off-by: David S. Miller --- drivers/net/ethernet/calxeda/xgmac.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c index cd5010b..78d6d6b 100644 --- a/drivers/net/ethernet/calxeda/xgmac.c +++ b/drivers/net/ethernet/calxeda/xgmac.c @@ -466,6 +466,13 @@ static inline void desc_set_tx_owner(struct xgmac_dma_desc *p, u32 flags) p->flags = cpu_to_le32(tmpflags); } +static inline void desc_clear_tx_owner(struct xgmac_dma_desc *p) +{ + u32 tmpflags = le32_to_cpu(p->flags); + tmpflags &= TXDESC_END_RING; + p->flags = cpu_to_le32(tmpflags); +} + static inline int desc_get_tx_ls(struct xgmac_dma_desc *p) { return le32_to_cpu(p->flags) & TXDESC_LAST_SEG; @@ -1100,7 +1107,7 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev) paddr = dma_map_single(priv->device, skb->data, len, DMA_TO_DEVICE); if (dma_mapping_error(priv->device, paddr)) { dev_kfree_skb(skb); - return -EIO; + return NETDEV_TX_OK; } priv->tx_skbuff[entry] = skb; desc_set_buf_addr_and_size(desc, paddr, len); @@ -1112,10 +1119,8 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev) paddr = skb_frag_dma_map(priv->device, frag, 0, len, DMA_TO_DEVICE); - if (dma_mapping_error(priv->device, paddr)) { - dev_kfree_skb(skb); - return -EIO; - } + if (dma_mapping_error(priv->device, paddr)) + goto dma_err; entry = dma_ring_incr(entry, DMA_TX_RING_SZ); desc = priv->dma_tx + entry; @@ -1151,6 +1156,22 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev) netif_start_queue(dev); } return NETDEV_TX_OK; + +dma_err: + entry = priv->tx_head; + for ( ; i > 0; i--) { + entry = dma_ring_incr(entry, DMA_TX_RING_SZ); + desc = priv->dma_tx + entry; + priv->tx_skbuff[entry] = NULL; + dma_unmap_page(priv->device, desc_get_buf_addr(desc), + desc_get_buf_len(desc), DMA_TO_DEVICE); + desc_clear_tx_owner(desc); + } + desc = first; + dma_unmap_single(priv->device, desc_get_buf_addr(desc), + desc_get_buf_len(desc), DMA_TO_DEVICE); + dev_kfree_skb(skb); + return NETDEV_TX_OK; } static int xgmac_rx(struct xgmac_priv *priv, int limit) -- 2.7.4