[patch 129/149] ucc_geth: Fix full TX queue processing

Greg KH
2010-07-01T18:30:01Z

2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Jiajun Wu <b06378@freescale.com>

commit 34692421bc7d6145ef383b014860f4fde10b7505 upstream.

commit 7583605b6d29f1f7f6fc505b883328089f3485ad ("ucc_geth: Fix empty
TX queue processing") fixed empty TX queue mishandling, but didn't
account another corner case: when TX queue becomes full.

Without this patch the driver will stop transmiting when TX queue
becomes full since 'bd == ugeth->txBd[txQ]' actually checks for
two things: queue empty or full.

Let's better check for NULL skb, which unambiguously signals an empty
queue.

Signed-off-by: Jiajun Wu <b06378@freescale.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/ucc_geth.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -3276,13 +3276,12 @@ static int ucc_geth_tx(struct net_device
/* Handle the transmitted buffer and release */
/* the BD to be used with the current frame */

- if (bd == ugeth->txBd[txQ]) /* queue empty? */
+ skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]];
+ if (!skb)
break;

dev->stats.tx_packets++;

- skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]];
-
if (skb_queue_len(&ugeth->rx_recycle) < RX_BD_RING_LEN &&
skb_recycle_check(skb,
ugeth->ug_info->uf_info.max_rx_buf_length +