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

Linas Vepstas
2006-10-03T20:57:33Z

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@austin.ibm.com>
Cc: James K Lewis <jklewis@us.ibm.com>
Cc: Arnd Bergmann <arnd@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);
}

/**