support for USB autosuspend in the asix driver

this implements support for USB autosuspend in the asix USB ethernet
driver.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 37bf4f2..3034d1a 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -590,6 +590,7 @@
 	dev->flags = 0;
 	del_timer_sync (&dev->delay);
 	tasklet_kill (&dev->bh);
+	usb_autopm_put_interface(dev->intf);
 
 	return 0;
 }
@@ -603,9 +604,19 @@
 static int usbnet_open (struct net_device *net)
 {
 	struct usbnet		*dev = netdev_priv(net);
-	int			retval = 0;
+	int			retval;
 	struct driver_info	*info = dev->driver_info;
 
+	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
+		if (netif_msg_ifup (dev))
+			devinfo (dev,
+				"resumption fail (%d) usbnet usb-%s-%s, %s",
+				retval,
+				dev->udev->bus->bus_name, dev->udev->devpath,
+			info->description);
+		goto done_nopm;
+	}
+
 	// put into "known safe" state
 	if (info->reset && (retval = info->reset (dev)) < 0) {
 		if (netif_msg_ifup (dev))
@@ -659,7 +670,10 @@
 
 	// delay posting reads until we're fully open
 	tasklet_schedule (&dev->bh);
+	return retval;
 done:
+	usb_autopm_put_interface(dev->intf);
+done_nopm:
 	return retval;
 }
 
@@ -1143,6 +1157,7 @@
 
 	dev = netdev_priv(net);
 	dev->udev = xdev;
+	dev->intf = udev;
 	dev->driver_info = info;
 	dev->driver_name = name;
 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
@@ -1267,12 +1282,18 @@
 	struct usbnet		*dev = usb_get_intfdata(intf);
 
 	if (!dev->suspend_count++) {
-		/* accelerate emptying of the rx and queues, to avoid
+		/*
+		 * accelerate emptying of the rx and queues, to avoid
 		 * having everything error out.
 		 */
 		netif_device_detach (dev->net);
 		(void) unlink_urbs (dev, &dev->rxq);
 		(void) unlink_urbs (dev, &dev->txq);
+		/*
+		 * reattach so runtime management can use and
+		 * wake the device
+		 */
+		netif_device_attach (dev->net);
 	}
 	return 0;
 }
@@ -1282,10 +1303,9 @@
 {
 	struct usbnet		*dev = usb_get_intfdata(intf);
 
-	if (!--dev->suspend_count) {
-		netif_device_attach (dev->net);
+	if (!--dev->suspend_count)
 		tasklet_schedule (&dev->bh);
-	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);