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 <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/net/catc.c

···
  * Transmit routines.
  */
 
-static void catc_tx_run(struct catc *catc)
+static int catc_tx_run(struct catc *catc)
 {
 	int status;
 
···
 	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.");
···
 
 	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);
 
···
 {
 	struct catc *catc = netdev_priv(netdev);
 	unsigned long flags;
+	int r = 0;
 	char *tx_buf;
 
 	spin_lock_irqsave(&catc->tx_lock, flags);
···
 	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))))
···
 
 	spin_unlock_irqrestore(&catc->tx_lock, flags);
 
-	catc->stats.tx_bytes += skb->len;
-	catc->stats.tx_packets++;
+	if (r >= 0) {
+		catc->stats.tx_bytes += skb->len;
+		catc->stats.tx_packets++;
+	}
 
 	dev_kfree_skb(skb);