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Commit 92cd4253 authored by Rob Herring's avatar Rob Herring Committed by David S. Miller
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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: default avatarAndreas Herrmann <andreas.herrmann@calxeda.com>
Signed-off-by: default avatarRob Herring <rob.herring@calxeda.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 531cda20

drivers/net/ethernet/calxeda/xgmac.c

+26 −5
Original line number Diff line number Diff line
@@ -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)