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-rw-r--r--net/atm/br2684.c36
1 files changed, 22 insertions, 14 deletions
diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 4819d31533e0..8eb6fbe8d8dd 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -74,6 +74,7 @@ struct br2684_vcc {
struct br2684_filter filter;
#endif /* CONFIG_ATM_BR2684_IPFILTER */
unsigned int copies_needed, copies_failed;
+ atomic_t qspace;
};
struct br2684_dev {
@@ -181,18 +182,15 @@ static struct notifier_block atm_dev_notifier = {
static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
{
struct br2684_vcc *brvcc = BR2684_VCC(vcc);
- struct net_device *net_dev = skb->dev;
- pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
+ pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
brvcc->old_pop(vcc, skb);
- if (!net_dev)
- return;
-
- if (atm_may_send(vcc, 0))
- netif_wake_queue(net_dev);
-
+ /* If the queue space just went up from zero, wake */
+ if (atomic_inc_return(&brvcc->qspace) == 1)
+ netif_wake_queue(brvcc->device);
}
+
/*
* Send a packet out a particular vcc. Not to useful right now, but paves
* the way for multiple vcc's per itf. Returns true if we can send,
@@ -256,16 +254,19 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
ATM_SKB(skb)->atm_options = atmvcc->atm_options;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
- atmvcc->send(atmvcc, skb);
- if (!atm_may_send(atmvcc, 0)) {
+ if (atomic_dec_return(&brvcc->qspace) < 1) {
+ /* No more please! */
netif_stop_queue(brvcc->device);
- /*check for race with br2684_pop*/
- if (atm_may_send(atmvcc, 0))
- netif_start_queue(brvcc->device);
+ /* We might have raced with br2684_pop() */
+ if (unlikely(atomic_read(&brvcc->qspace) > 0))
+ netif_wake_queue(brvcc->device);
}
- return 1;
+ /* If this fails immediately, the skb will be freed and br2684_pop()
+ will wake the queue if appropriate. Just return an error so that
+ the stats are updated correctly */
+ return !atmvcc->send(atmvcc, skb);
}
static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
@@ -504,6 +505,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
if (!brvcc)
return -ENOMEM;
+ /*
+ * Allow two packets in the ATM queue. One actually being sent, and one
+ * for the ATM 'TX done' handler to send. It shouldn't take long to get
+ * the next one from the netdev queue, when we need it. More than that
+ * would be bufferbloat.
+ */
+ atomic_set(&brvcc->qspace, 2);
write_lock_irq(&devs_lock);
net_dev = br2684_find_dev(&be.ifspec);
if (net_dev == NULL) {