[NET]: Remove gratuitous use of skb->tail in network drivers.
Many drivers use skb->tail unnecessarily.
In these situations, the code roughly looks like:
dev = dev_alloc_skb(...);
[optional] skb_reserve(skb, ...);
... skb->tail ...
But even if the skb_reserve() happens, skb->data equals
skb->tail. So it doesn't make any sense to use anything
other than skb->data in these cases.
Another case was the s2io.c driver directly mucking with
the skb->data and skb->tail pointers. It really just wanted
to do an skb_reserve(), so that's what the code was changed
to do instead.
Another reason I'm making this change as it allows some SKB
cleanups I have planned simpler to merge. In those cleanups,
skb->head, skb->tail, and skb->end pointers are removed, and
replaced with skb->head_room and skb->tail_room integers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index dd357dd..fc353e3 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c
@@ -446,13 +446,13 @@
mapping =
de->rx_skb[rx_tail].mapping =
- pci_map_single(de->pdev, copy_skb->tail,
+ pci_map_single(de->pdev, copy_skb->data,
buflen, PCI_DMA_FROMDEVICE);
de->rx_skb[rx_tail].skb = copy_skb;
} else {
pci_dma_sync_single_for_cpu(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
skb_reserve(copy_skb, RX_OFFSET);
- memcpy(skb_put(copy_skb, len), skb->tail, len);
+ memcpy(skb_put(copy_skb, len), skb->data, len);
pci_dma_sync_single_for_device(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
@@ -1269,7 +1269,7 @@
skb->dev = de->dev;
de->rx_skb[i].mapping = pci_map_single(de->pdev,
- skb->tail, de->rx_buf_sz, PCI_DMA_FROMDEVICE);
+ skb->data, de->rx_buf_sz, PCI_DMA_FROMDEVICE);
de->rx_skb[i].skb = skb;
de->rx_ring[i].opts1 = cpu_to_le32(DescOwn);