redonkable/alistair23-linux
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gianfar: fix headroom expansion code

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The code that was added to increase headroom was wrong.
It doesn't handle the case where gfar_add_fcb() changes the skb.
Better to do check at start of transmit (outside of lock), where
error handling is better anyway.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2009-03-27 00:38:45 -07:00 committed by David S. Miller
parent 83e0bbcbe2
commit 54dc79fe0d
1 changed files with 24 additions and 22 deletions
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46
drivers/net/gianfar.c
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@ -1239,19 +1239,9 @@ static int gfar_enet_open(struct net_device *dev)
return err;
}
static inline struct txfcb *gfar_add_fcb(struct sk_buff **skbp)
static inline struct txfcb *gfar_add_fcb(struct sk_buff *skb)
{
struct txfcb *fcb;
struct sk_buff *skb = *skbp;
if (unlikely(skb_headroom(skb) < GMAC_FCB_LEN)) {
struct sk_buff *old_skb = skb;
skb = skb_realloc_headroom(old_skb, GMAC_FCB_LEN);
if (!skb)
return NULL;
dev_kfree_skb_any(old_skb);
}
fcb = (struct txfcb *)skb_push(skb, GMAC_FCB_LEN);
struct txfcb *fcb = (struct txfcb *)skb_push(skb, GMAC_FCB_LEN);
cacheable_memzero(fcb, GMAC_FCB_LEN);
return fcb;
@ -1320,6 +1310,20 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
base = priv->tx_bd_base;
/* make space for additional header */
if (skb_headroom(skb) < GMAC_FCB_LEN) {
struct sk_buff *skb_new;
skb_new = skb_realloc_headroom(skb, GMAC_FCB_LEN);
if (!skb_new) {
dev->stats.tx_errors++;
kfree(skb);
return NETDEV_TX_OK;
}
kfree_skb(skb);
skb = skb_new;
}
/* total number of fragments in the SKB */
nr_frags = skb_shinfo(skb)->nr_frags;
@ -1372,20 +1376,18 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
/* Set up checksumming */
if (CHECKSUM_PARTIAL == skb->ip_summed) {
fcb = gfar_add_fcb(&skb);
if (likely(fcb != NULL)) {
lstatus |= BD_LFLAG(TXBD_TOE);
gfar_tx_checksum(skb, fcb);
}
fcb = gfar_add_fcb(skb);
lstatus |= BD_LFLAG(TXBD_TOE);
gfar_tx_checksum(skb, fcb);
}
if (priv->vlgrp && vlan_tx_tag_present(skb)) {
if (unlikely(NULL == fcb))
fcb = gfar_add_fcb(&skb);
if (likely(fcb != NULL)) {
if (unlikely(NULL == fcb)) {
fcb = gfar_add_fcb(skb);
lstatus |= BD_LFLAG(TXBD_TOE);
gfar_tx_vlan(skb, fcb);
}
gfar_tx_vlan(skb, fcb);
}
/* setup the TxBD length and buffer pointer for the first BD */
@ -1433,7 +1435,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
/* Unlock priv */
spin_unlock_irqrestore(&priv->txlock, flags);
return 0;
return NETDEV_TX_OK;
}
/* Stops the kernel queue, and halts the controller */