[PATCH] virtio_net: Fix queue full check

[Krishna Kumar <krkumar2@in.ibm.com>]

I get many queue full errors being wrongly reported when running
parallel netperfs:

Oct 17 10:22:40 localhost kernel: net eth0: Unexpected TX queue failure: -28
Oct 17 10:28:22 localhost kernel: net eth0: Unexpected TX queue failure: -28
Oct 17 10:35:58 localhost kernel: net eth0: Unexpected TX queue failure: -28
Oct 17 10:41:06 localhost kernel: net eth0: Unexpected TX queue failure: -28

I initially changed the check from -ENOMEM to -ENOSPC, but
virtqueue_add_buf can return only -ENOSPC when it doesn't have
space for new request.  Patch removes redundant checks but
displays the failure errno.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
---
 drivers/net/virtio_net.c |   15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff -ruNp org/drivers/net/virtio_net.c new/drivers/net/virtio_net.c
--- org/drivers/net/virtio_net.c	2010-10-11 10:20:02.000000000 +0530
+++ new/drivers/net/virtio_net.c	2010-10-21 17:37:45.000000000 +0530
@@ -570,17 +570,10 @@ static netdev_tx_t start_xmit(struct sk_
 
 	/* This can happen with OOM and indirect buffers. */
 	if (unlikely(capacity < 0)) {
-		if (net_ratelimit()) {
-			if (likely(capacity == -ENOMEM)) {
-				dev_warn(&dev->dev,
-					 "TX queue failure: out of memory\n");
-			} else {
-				dev->stats.tx_fifo_errors++;
-				dev_warn(&dev->dev,
-					 "Unexpected TX queue failure: %d\n",
-					 capacity);
-			}
-		}
+		if (net_ratelimit())
+			dev_warn(&dev->dev,
+				 "TX queue failure (%d): out of memory\n",
+				 capacity); 
 		dev->stats.tx_dropped++;
 		kfree_skb(skb);
 		return NETDEV_TX_OK;