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[PATCH] chelesio: transmit locking (plus bug fix).

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If transmit lock is contended on, then push return code back
and retry at higher level.

Bugfix: If buffer is reallocated because of lack of headroom
and the send is blocked, then drop packet. This is necessary
because caller would end up requeuing a freed skb.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Stephen Hemminger 2006-12-01 16:36:22 -08:00 committed by Jeff Garzik
parent 56f643c28c
commit cabdfb373a
1 changed files with 15 additions and 4 deletions
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19
drivers/net/chelsio/sge.c
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@ -1778,7 +1778,9 @@ static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
struct cmdQ *q = &sge->cmdQ[qid];
unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
spin_lock(&q->lock);
if (!spin_trylock(&q->lock))
return NETDEV_TX_LOCKED;
reclaim_completed_tx(sge, q);
pidx = q->pidx;
@ -1887,6 +1889,8 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
struct sge *sge = adapter->sge;
struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[dev->if_port], smp_processor_id());
struct cpl_tx_pkt *cpl;
struct sk_buff *orig_skb = skb;
int ret;
if (skb->protocol == htons(ETH_P_CPL5))
goto send;
@ -1930,8 +1934,6 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
* Complain when this happens but try to fix things up.
*/
if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
struct sk_buff *orig_skb = skb;
pr_debug("%s: headroom %d header_len %d\n", dev->name,
skb_headroom(skb), dev->hard_header_len);
@ -1991,7 +1993,16 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
send:
st->tx_packets++;
dev->trans_start = jiffies;
return t1_sge_tx(skb, adapter, 0, dev);
ret = t1_sge_tx(skb, adapter, 0, dev);
/* If transmit busy, and we reallocated skb's due to headroom limit,
* then silently discard to avoid leak.
*/
if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
dev_kfree_skb_any(skb);
ret = NETDEV_TX_OK;
}
return ret;
}
/*