usbnet: fix usb_autopm_get_interface failure(v1)

Since usbnet already took usb runtime pm, we have to
enable runtime pm for usb interface of usbnet, otherwise
usb_autopm_get_interface may return failure and cause
'ifconfig usb0 up' failed if USB_SUSPEND(RUNTIME_PM) is
enabled.

Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index ca7fc9df1ccf900533d56c35326b360316283af2..c04d49e31f814fe11d2f1b730dcba014afeb324c 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -45,6 +45,7 @@
 #include <linux/usb/usbnet.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/pm_runtime.h>
 
 #define DRIVER_VERSION         "22-Aug-2005"
 
@@ -1273,6 +1274,16 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
        struct usb_device               *xdev;
        int                             status;
        const char                      *name;
+       struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
+
+       /* usbnet already took usb runtime pm, so have to enable the feature
+        * for usb interface, otherwise usb_autopm_get_interface may return
+        * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
+        */
+       if (!driver->supports_autosuspend) {
+               driver->supports_autosuspend = 1;
+               pm_runtime_enable(&udev->dev);
+       }
 
        name = udev->dev.driver->name;
        info = (struct driver_info *) prod->driver_info;