fec: fix FEC driver packet transmission breakage (9555b31e) · Commits · 戴 / test

Commit ("FEC Buffer rework") breaks transmission of packets where the skb data buffer is not memory aligned according to FEC_ALIGNMENT. It incorrectly passes to dma_sync_single() the buffer address directly from the skb, instead of the address calculated for use (which may be the skb address or one of the bounce buffers). It seems there is no use converting the cpu address of the buffer to a physical either, since dma_map_single() expects the cpu address and will return the dma address to use in the descriptor. So remove the use of __pa() on the buffer address as well. This patch is against 2.6.30-rc5. This breakage is a regression over 2.6.30, which does not have this problem. Signed-off-by:

Greg Ungerer <gerg@uclinux.org> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/fec.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -285,6 +285,7 @@ fec_enet_start_xmit(struct sk_buff skb, struct net_device dev)
		{
		struct fec_enet_private *fep = netdev_priv(dev);
		struct bufdesc *bdp;
		void *bufaddr;
		unsigned short status;
		unsigned long flags;

		@@ -312,7 +313,7 @@ fec_enet_start_xmit(struct sk_buff skb, struct net_device dev)
		status &= ~BD_ENET_TX_STATS;

		/* Set buffer length and buffer pointer */
		bdp->cbd_bufaddr = __pa(skb->data);
		bufaddr = skb->data;
		bdp->cbd_datlen = skb->len;

		/*
		@@ -320,11 +321,11 @@ fec_enet_start_xmit(struct sk_buff skb, struct net_device dev)
		* 4-byte boundaries. Use bounce buffers to copy data
		* and get it aligned. Ugh.
		*/
		if (bdp->cbd_bufaddr & FEC_ALIGNMENT) {
		if (((unsigned long) bufaddr) & FEC_ALIGNMENT) {
		unsigned int index;
		index = bdp - fep->tx_bd_base;
		memcpy(fep->tx_bounce[index], (void *)skb->data, skb->len);
		bdp->cbd_bufaddr = __pa(fep->tx_bounce[index]);
		bufaddr = fep->tx_bounce[index];
		}

		/* Save skb pointer */
		@@ -336,7 +337,7 @@ fec_enet_start_xmit(struct sk_buff skb, struct net_device dev)
		/* Push the data cache so the CPM does not get stale memory
		* data.
		*/
		bdp->cbd_bufaddr = dma_map_single(&dev->dev, skb->data,
		bdp->cbd_bufaddr = dma_map_single(&dev->dev, bufaddr,
		FEC_ENET_TX_FRSIZE, DMA_TO_DEVICE);

		/* Send it on its way. Tell FEC it's ready, interrupt when done,

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