USB: fix catc error handling

this driver ignores errors while starting the transmit queue. It will
never be reported stopped as the completion handler won't run
and it will never be started again as it will be considered started.
This patch adds error handling.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/net/catc.c

@@ -355,7 +355,7 @@ static void catc_irq_done(struct urb *urb)
  * Transmit routines.
  */
 
-static void catc_tx_run(struct catc *catc)
+static int catc_tx_run(struct catc *catc)
 {
 	int status;
 
@@ -373,12 +373,14 @@ static void catc_tx_run(struct catc *catc)
 	catc->tx_ptr = 0;
 
 	catc->netdev->trans_start = jiffies;
+	return status;
 }
 
 static void catc_tx_done(struct urb *urb)
 {
 	struct catc *catc = urb->context;
 	unsigned long flags;
+	int r;
 
 	if (urb->status == -ECONNRESET) {
 		dbg("Tx Reset.");
@@ -397,10 +399,13 @@ static void catc_tx_done(struct urb *urb)
 
 	spin_lock_irqsave(&catc->tx_lock, flags);
 
-	if (catc->tx_ptr)
-		catc_tx_run(catc);
-	else
+	if (catc->tx_ptr) {
+		r = catc_tx_run(catc);
+		if (unlikely(r < 0))
+			clear_bit(TX_RUNNING, &catc->flags);
+	} else {
 		clear_bit(TX_RUNNING, &catc->flags);
+	}
 
 	netif_wake_queue(catc->netdev);
 
@@ -411,6 +416,7 @@ static int catc_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct catc *catc = netdev_priv(netdev);
 	unsigned long flags;
+	int r = 0;
 	char *tx_buf;
 
 	spin_lock_irqsave(&catc->tx_lock, flags);
@@ -421,8 +427,11 @@ static int catc_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 	skb_copy_from_linear_data(skb, tx_buf + 2, skb->len);
 	catc->tx_ptr += skb->len + 2;
 
-	if (!test_and_set_bit(TX_RUNNING, &catc->flags))
-		catc_tx_run(catc);
+	if (!test_and_set_bit(TX_RUNNING, &catc->flags)) {
+		r = catc_tx_run(catc);
+		if (r < 0)
+			clear_bit(TX_RUNNING, &catc->flags);
+	}
 
 	if ((catc->is_f5u011 && catc->tx_ptr)
 	     || (catc->tx_ptr >= ((TX_MAX_BURST - 1) * (PKT_SZ + 2))))
@@ -430,8 +439,10 @@ static int catc_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 
 	spin_unlock_irqrestore(&catc->tx_lock, flags);
 
+	if (r >= 0) {
 		catc->stats.tx_bytes += skb->len;
 		catc->stats.tx_packets++;
+	}
 
 	dev_kfree_skb(skb);