[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/sis900.c b/drivers/net/sis900.c
index 127324f..23b713c 100644
--- a/drivers/net/sis900.c
+++ b/drivers/net/sis900.c
@@ -1154,7 +1154,7 @@
sis_priv->rx_skbuff[i] = skb;
sis_priv->rx_ring[i].cmdsts = RX_BUF_SIZE;
sis_priv->rx_ring[i].bufptr = pci_map_single(sis_priv->pci_dev,
- skb->tail, RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+ skb->data, RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
}
sis_priv->dirty_rx = (unsigned int) (i - NUM_RX_DESC);
@@ -1776,7 +1776,7 @@
sis_priv->rx_skbuff[entry] = skb;
sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
sis_priv->rx_ring[entry].bufptr =
- pci_map_single(sis_priv->pci_dev, skb->tail,
+ pci_map_single(sis_priv->pci_dev, skb->data,
RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
sis_priv->dirty_rx++;
}
@@ -1809,7 +1809,7 @@
sis_priv->rx_skbuff[entry] = skb;
sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
sis_priv->rx_ring[entry].bufptr =
- pci_map_single(sis_priv->pci_dev, skb->tail,
+ pci_map_single(sis_priv->pci_dev, skb->data,
RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
}
}