From c46ac9463fbdee41723dd9fd108b2c1ffd30615f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 21 Aug 2007 01:33:42 +0200 Subject: [PATCH] DM9000: fix interface hang under load When transferring data at full speed, the DM9000 network interface sometimes stops sending/receiving data. Worse, ksoftirqd consumes 100% cpu and the net tx watchdog never triggers. Fix by spin_lock_irqsave() in dm9000_start_xmit() to prevent the interrupt handler from interfering. Signed-off-by: Florian Westphal Signed-off-by: Jeff Garzik --- drivers/net/dm9000.c | 25 +++++++------------------ 1 file changed, 7 insertions(+), 18 deletions(-) diff --git a/drivers/net/dm9000.c b/drivers/net/dm9000.c index c3de81bf09..738aa59065 100644 --- a/drivers/net/dm9000.c +++ b/drivers/net/dm9000.c @@ -700,6 +700,7 @@ dm9000_init_dm9000(struct net_device *dev) static int dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev) { + unsigned long flags; board_info_t *db = (board_info_t *) dev->priv; PRINTK3("dm9000_start_xmit\n"); @@ -707,10 +708,7 @@ dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev) if (db->tx_pkt_cnt > 1) return 1; - netif_stop_queue(dev); - - /* Disable all interrupts */ - iow(db, DM9000_IMR, IMR_PAR); + spin_lock_irqsave(&db->lock, flags); /* Move data to DM9000 TX RAM */ writeb(DM9000_MWCMD, db->io_addr); @@ -718,12 +716,9 @@ dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev) (db->outblk)(db->io_data, skb->data, skb->len); db->stats.tx_bytes += skb->len; + db->tx_pkt_cnt++; /* TX control: First packet immediately send, second packet queue */ - if (db->tx_pkt_cnt == 0) { - - /* First Packet */ - db->tx_pkt_cnt++; - + if (db->tx_pkt_cnt == 1) { /* Set TX length to DM9000 */ iow(db, DM9000_TXPLL, skb->len & 0xff); iow(db, DM9000_TXPLH, (skb->len >> 8) & 0xff); @@ -732,23 +727,17 @@ dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev) iow(db, DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */ dev->trans_start = jiffies; /* save the time stamp */ - } else { /* Second packet */ - db->tx_pkt_cnt++; db->queue_pkt_len = skb->len; + netif_stop_queue(dev); } + spin_unlock_irqrestore(&db->lock, flags); + /* free this SKB */ dev_kfree_skb(skb); - /* Re-enable resource check */ - if (db->tx_pkt_cnt == 1) - netif_wake_queue(dev); - - /* Re-enable interrupt */ - iow(db, DM9000_IMR, IMR_PAR | IMR_PTM | IMR_PRM); - return 0; } -- 2.39.5