usbnet: allow "minidriver" to prevent urb unlinking on usbnet_stop

rndis_wlan devices freeze after running usbnet_stop several times. It appears
that firmware freezes in state where it does not respond to any RNDIS commands
and device have to be physically unplugged/replugged. This patch lets
minidrivers to disable unlink_urbs on usbnet_stop through new info flag.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 14 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 25e435c4904..af1fe469650 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -601,21 +601,25 @@ int usbnet_stop (struct net_device *net)
                                 info->description);
         }
 
-        // ensure there are no more active urbs
-        add_wait_queue (&unlink_wakeup, &wait);
-        dev->wait = &unlink_wakeup;
-        temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
-
-        // maybe wait for deletions to finish.
-        while (!skb_queue_empty(&dev->rxq)
-                        && !skb_queue_empty(&dev->txq)
-                        && !skb_queue_empty(&dev->done)) {
-                msleep(UNLINK_TIMEOUT_MS);
-                if (netif_msg_ifdown (dev))
-                        devdbg (dev, "waited for %d urb completions", temp);
+        if (!(info->flags & FLAG_AVOID_UNLINK_URBS)) {
+                /* ensure there are no more active urbs */
+                add_wait_queue(&unlink_wakeup, &wait);
+                dev->wait = &unlink_wakeup;
+                temp = unlink_urbs(dev, &dev->txq) +
+                        unlink_urbs(dev, &dev->rxq);
+
+                /* maybe wait for deletions to finish. */
+                while (!skb_queue_empty(&dev->rxq)
+                                && !skb_queue_empty(&dev->txq)
+                                && !skb_queue_empty(&dev->done)) {
+                        msleep(UNLINK_TIMEOUT_MS);
+                        if (netif_msg_ifdown(dev))
+                                devdbg(dev, "waited for %d urb completions",
+                                        temp);
+                }
+                dev->wait = NULL;
+                remove_wait_queue(&unlink_wakeup, &wait);
         }
-        dev->wait = NULL;
-        remove_wait_queue (&unlink_wakeup, &wait);
 
         usb_kill_urb(dev->interrupt);