netdev - Re: Sundance network driver (D-Link DFE-580TX) timeouts rendering interface unusable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <1327936900.2297.7.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC>
Date:	Mon, 30 Jan 2012 16:21:40 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Ben Hutchings <ben@...adent.org.uk>
Cc:	Denis Kirjanov <kirjanov@...il.com>,
	"Mike ." <mike-bugreport@...mail.com>, 656476@...s.debian.org,
	netdev <netdev@...r.kernel.org>
Subject: Re: Sundance network driver (D-Link DFE-580TX) timeouts rendering
 interface unusable

Le lundi 30 janvier 2012 à 15:57 +0100, Eric Dumazet a écrit :

> Hmm, TX _completion_ is not run from tasklet but hardware IRQ, this is
> why I added the spin_lock_irqsave().
> 
> 
> Tasklet fires the TX, but hardware IRQ does the TX completion part.
> 
> This driver is ... interesting :)
> 

Oh well, we also must make sure we held np->lock in TX completion when
doing our test to eventually call netif_wake_queue(), I missed it was
released too early.

here is a more complete patch.

diff --git a/drivers/net/ethernet/dlink/sundance.c b/drivers/net/ethernet/dlink/sundance.c
index 28a3a9b..d5e9472 100644
--- a/drivers/net/ethernet/dlink/sundance.c
+++ b/drivers/net/ethernet/dlink/sundance.c
@@ -1099,11 +1099,13 @@ start_tx (struct sk_buff *skb, struct net_device *dev)
 	tasklet_schedule(&np->tx_tasklet);
 
 	/* On some architectures: explicitly flush cache lines here. */
-	if (np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 1 &&
-	    !netif_queue_stopped(dev)) {
-		/* do nothing */
-	} else {
-		netif_stop_queue (dev);
+	if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&np->lock, flags);
+		if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1)
+			netif_stop_queue(dev);
+		spin_unlock_irqrestore(&np->lock, flags);
 	}
 	if (netif_msg_tx_queued(np)) {
 		printk (KERN_DEBUG
@@ -1242,8 +1244,8 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
 			hw_frame_id = ioread8(ioaddr + TxFrameId);
 		}
 
+		spin_lock(&np->lock);
 		if (np->pci_dev->revision >= 0x14) {
-			spin_lock(&np->lock);
 			for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
 				int entry = np->dirty_tx % TX_RING_SIZE;
 				struct sk_buff *skb;
@@ -1267,9 +1269,7 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
 				np->tx_ring[entry].frag[0].addr = 0;
 				np->tx_ring[entry].frag[0].length = 0;
 			}
-			spin_unlock(&np->lock);
 		} else {
-			spin_lock(&np->lock);
 			for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
 				int entry = np->dirty_tx % TX_RING_SIZE;
 				struct sk_buff *skb;
@@ -1286,7 +1286,6 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
 				np->tx_ring[entry].frag[0].addr = 0;
 				np->tx_ring[entry].frag[0].length = 0;
 			}
-			spin_unlock(&np->lock);
 		}
 
 		if (netif_queue_stopped(dev) &&
@@ -1294,6 +1293,7 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
 			/* The ring is no longer full, clear busy flag. */
 			netif_wake_queue (dev);
 		}
+		spin_unlock(&np->lock);
 		/* Abnormal error summary/uncommon events handlers. */
 		if (intr_status & (IntrPCIErr | LinkChange | StatsMax))
 			netdev_error(dev, intr_status);


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html