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>

3 files changed, 25 insertions, 17 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 25e435c49040..af1fe4696509 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);
 
diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index 09c0702ae645..76c5ec6bbbc5 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -2513,7 +2513,8 @@ static int rndis_wlan_stop(struct usbnet *usbdev)
 
 static const struct driver_info bcm4320b_info = {
         .description =  "Wireless RNDIS device, BCM4320b based",
-        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT,
+        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT |
+                                FLAG_AVOID_UNLINK_URBS,
         .bind =         rndis_wlan_bind,
         .unbind =       rndis_wlan_unbind,
         .status =       rndis_status,
@@ -2527,7 +2528,8 @@ static const struct driver_info	bcm4320b_info = {
 
 static const struct driver_info bcm4320a_info = {
         .description =  "Wireless RNDIS device, BCM4320a based",
-        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT,
+        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT |
+                                FLAG_AVOID_UNLINK_URBS,
         .bind =         rndis_wlan_bind,
         .unbind =       rndis_wlan_unbind,
         .status =       rndis_status,
@@ -2541,7 +2543,8 @@ static const struct driver_info	bcm4320a_info = {
 
 static const struct driver_info rndis_wlan_info = {
         .description =  "Wireless RNDIS device",
-        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT,
+        .flags =        FLAG_WLAN | FLAG_FRAMING_RN | FLAG_NO_SETINT |
+                                FLAG_AVOID_UNLINK_URBS,
         .bind =         rndis_wlan_bind,
         .unbind =       rndis_wlan_unbind,
         .status =       rndis_status,
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 7c17b2efba86..c642f78dd9cf 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -86,6 +86,7 @@ struct driver_info {
 
 #define FLAG_FRAMING_AX 0x0040          /* AX88772/178 packets */
 #define FLAG_WLAN       0x0080          /* use "wlan%d" names */
+#define FLAG_AVOID_UNLINK_URBS 0x0100   /* don't unlink urbs at usbnet_stop() */
 
 
         /* init device ... can sleep, or cause probe() failure */