usbnet: Stop RX Q on MTU change

When MTU is changed unlink_urbs() flushes RX Q but mean while usbnet_bh()
can fill up the Q at the same time.
Depends on which HCD is down there unlink takes long time then the flush
never ends.

Signed-off-by: Soohoon Lee <soohoon.lee@f5.com>
Reviewed-by: Kimball Murray <kmurray@f5.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 61ba46404937..6086a0163249 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -395,8 +395,11 @@ int usbnet_change_mtu (struct net_device *net, int new_mtu)
         dev->hard_mtu = net->mtu + net->hard_header_len;
         if (dev->rx_urb_size == old_hard_mtu) {
                 dev->rx_urb_size = dev->hard_mtu;
-                if (dev->rx_urb_size > old_rx_urb_size)
+                if (dev->rx_urb_size > old_rx_urb_size) {
+                        usbnet_pause_rx(dev);
                         usbnet_unlink_rx_urbs(dev);
+                        usbnet_resume_rx(dev);
+                }
         }
 
         /* max qlen depend on hard_mtu and rx_urb_size */
@@ -1508,8 +1511,9 @@ static void usbnet_bh (unsigned long param)
         } else if (netif_running (dev->net) &&
                    netif_device_present (dev->net) &&
                    netif_carrier_ok(dev->net) &&
-                   !timer_pending (&dev->delay) &&
-                   !test_bit (EVENT_RX_HALT, &dev->flags)) {
+                   !timer_pending(&dev->delay) &&
+                   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
+                   !test_bit(EVENT_RX_HALT, &dev->flags)) {
                 int     temp = dev->rxq.qlen;
 
                 if (temp < RX_QLEN(dev)) {