1 files changed, 44 insertions, 1 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 51f3192f3931..1e5a9b72650e 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -938,6 +938,27 @@ static const struct ethtool_ops usbnet_ethtool_ops = {
 
 /*-------------------------------------------------------------------------*/
 
+static void __handle_link_change(struct usbnet *dev)
+{
+	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
+		return;
+
+	if (!netif_carrier_ok(dev->net)) {
+		/* kill URBs for reading packets to save bus bandwidth */
+		unlink_urbs(dev, &dev->rxq);
+
+		/*
+		 * tx_timeout will unlink URBs for sending packets and
+		 * tx queue is stopped by netcore after link becomes off
+		 */
+	} else {
+		/* submitting URBs for reading packets */
+		tasklet_schedule(&dev->bh);
+	}
+
+	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
+}
+
 /* work that cannot be done in interrupt context uses keventd.
  *
  * NOTE:  with 2.5 we could do more of this using completion callbacks,
@@ -1035,8 +1056,14 @@ skip_reset:
 		} else {
 			usb_autopm_put_interface(dev->intf);
 		}
+
+		/* handle link change from link resetting */
+		__handle_link_change(dev);
 	}
 
+	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
+		__handle_link_change(dev);
+
 	if (dev->flags)
 		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
 }
@@ -1286,6 +1313,7 @@ static void usbnet_bh (unsigned long param)
 	// or are we maybe short a few urbs?
 	} 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)) {
 		int	temp = dev->rxq.qlen;
@@ -1521,7 +1549,7 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
 	netif_device_attach (net);
 
 	if (dev->driver_info->flags & FLAG_LINK_INTR)
-		netif_carrier_off(net);
+		usbnet_link_change(dev, 0, 0);
 
 	return 0;
 
@@ -1653,6 +1681,21 @@ int usbnet_manage_power(struct usbnet *dev, int on)
 }
 EXPORT_SYMBOL(usbnet_manage_power);
 
+void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
+{
+	/* update link after link is reseted */
+	if (link && !need_reset)
+		netif_carrier_on(dev->net);
+	else
+		netif_carrier_off(dev->net);
+
+	if (need_reset && link)
+		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
+	else
+		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
+}
+EXPORT_SYMBOL(usbnet_link_change);
+
 /*-------------------------------------------------------------------------*/
 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
 			     u16 value, u16 index, void *data, u16 size)