cns3xxx: ethernet - clean up tx descs only when needed

We already clean up tx descriptors in the napi eth_poll() function so it
would likely be rare to run out of available descriptors in eth_xmit. Thus
we can clean them up only when needed and return busy only when we
still don't have enough.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

SVN-Revision: 39762
This commit is contained in:
Felix Fietkau 2014-02-27 23:02:43 +00:00
parent 96eb3d883d
commit 8665c57923

View File

@ -583,7 +583,7 @@ static void eth_check_num_used(struct _tx_ring *tx_ring)
}
}
static void eth_complete_tx(struct sw *sw)
static int eth_complete_tx(struct sw *sw)
{
struct _tx_ring *tx_ring = &sw->tx_ring;
struct tx_desc *desc;
@ -615,6 +615,8 @@ static void eth_complete_tx(struct sw *sw)
tx_ring->free_index = index;
tx_ring->num_used -= i;
eth_check_num_used(tx_ring);
return TX_DESCS - tx_ring->num_used;
}
static int eth_poll(struct napi_struct *napi, int budget)
@ -776,11 +778,13 @@ static int eth_xmit(struct sk_buff *skb, struct net_device *dev)
skb_walk_frags(skb, skb1)
nr_desc++;
eth_schedule_poll(sw);
spin_lock_bh(&tx_lock);
if ((tx_ring->num_used + nr_desc + 1) >= TX_DESCS) {
spin_unlock_bh(&tx_lock);
return NETDEV_TX_BUSY;
/* clean up tx descriptors when needed */
if (eth_complete_tx(sw) < nr_desc) {
spin_unlock_bh(&tx_lock);
return NETDEV_TX_BUSY;
}
}
index = index0 = tx_ring->cur_index;