From 8665c57923fa16474713b845f96e703d22304091 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Thu, 27 Feb 2014 23:02:43 +0000
Subject: [PATCH] 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
---
.../files/drivers/net/ethernet/cavium/cns3xxx_eth.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
index bbbbf5c091..9692d47994 100644
--- a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
+++ b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
@@ -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;
--
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