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>

3 files changed, 27 insertions, 5 deletions

diff --git a/drivers/net/usb/asix.c b/drivers/net/usb/asix.c
index 6d95cacd5284..61daa096de66 100644
--- a/drivers/net/usb/asix.c
+++ b/drivers/net/usb/asix.c
@@ -1474,6 +1474,7 @@ static struct usb_driver asix_driver = {
         .suspend =      usbnet_suspend,
         .resume =       usbnet_resume,
         .disconnect =   usbnet_disconnect,
+        .supports_autosuspend = 1,
 };
 
 static int __init asix_init(void)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 37bf4f2c0a44..3034d1aea376 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -590,6 +590,7 @@ static int usbnet_stop (struct net_device *net)
         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_stop (struct net_device *net)
 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 @@ static int usbnet_open (struct net_device *net)
 
         // 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 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
 
         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 @@ int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
         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 @@ int usbnet_resume (struct usb_interface *intf)
 {
         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);
diff --git a/drivers/net/usb/usbnet.h b/drivers/net/usb/usbnet.h
index a6c5820767de..1fae4347e831 100644
--- a/drivers/net/usb/usbnet.h
+++ b/drivers/net/usb/usbnet.h
@@ -28,6 +28,7 @@
 struct usbnet {
         /* housekeeping */
         struct usb_device       *udev;
+        struct usb_interface    *intf;
         struct driver_info      *driver_info;
         const char              *driver_name;
         wait_queue_head_t       *wait;