[PATCH 1/4]: Spidernet stop queue when queue is full

[Linas Vepstas]

Subject: [PATCH 1/4]: Spidernet stop queue when queue is full.

This patch adds a call to netif_stop_queue() when there is
no more room for more packets on the transmit queue.

Signed-off-by: Linas Vepstas <linas at austin.ibm.com>
Cc: James K Lewis <jklewis at us.ibm.com>
Cc: Arnd Bergmann <arnd at arndb.de>

----
 drivers/net/spider_net.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

Index: linux-2.6.18-mm2/drivers/net/spider_net.c
===================================================================
--- linux-2.6.18-mm2.orig/drivers/net/spider_net.c	2006-10-02 12:12:56.000000000 -0500
+++ linux-2.6.18-mm2/drivers/net/spider_net.c	2006-10-02 18:59:43.000000000 -0500
@@ -686,6 +686,7 @@ spider_net_prepare_tx_descr(struct spide
 	/* Chain the bus address, so that the DMA engine finds this descr. */
 	descr->prev->next_descr_addr = descr->bus_addr;
 
+	card->netdev->trans_start = jiffies;
 	return 0;
 }
 
@@ -857,29 +858,23 @@ spider_net_xmit(struct sk_buff *skb, str
 
 	spider_net_release_tx_chain(card, 0);
 
-	if (chain->head->next == chain->tail->prev) {
-		card->netdev_stats.tx_dropped++;
-		result = NETDEV_TX_LOCKED;
-		goto out;
-	}
-
-	if (spider_net_get_descr_status(descr) != SPIDER_NET_DESCR_NOT_IN_USE) {
-		card->netdev_stats.tx_dropped++;
+	if ((chain->head->next == chain->tail->prev) ||
+	   (spider_net_get_descr_status(descr) != SPIDER_NET_DESCR_NOT_IN_USE)) {
 		result = NETDEV_TX_LOCKED;
 		goto out;
 	}
 
 	if (spider_net_prepare_tx_descr(card, skb) != 0) {
-		card->netdev_stats.tx_dropped++;
 		result = NETDEV_TX_BUSY;
 		goto out;
 	}
 
-	result = NETDEV_TX_OK;
 	spider_net_kick_tx_dma(card);
+	return NETDEV_TX_OK;
 
 out:
-	netif_wake_queue(netdev);
+	card->netdev_stats.tx_dropped++;
+	netif_stop_queue(netdev);
 	return result;
 }
 
@@ -898,6 +893,8 @@ spider_net_cleanup_tx_ring(struct spider
 	if ((spider_net_release_tx_chain(card, 0) != 0) &&
 	    (card->netdev->flags & IFF_UP))
 		spider_net_kick_tx_dma(card);
+
+	netif_wake_queue(card->netdev);
 }
 
 /**