USB: code cleanup in suspend/resume path (3rd try)

Do the cleanup to avoid behaviorial parameters Linus
requested.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/driver.c

@@ -958,13 +958,8 @@ void usb_rebind_intf(struct usb_interface *intf)
 	int rc;
 
 	/* Delayed unbind of an existing driver */
-	if (intf->dev.driver) {
-		struct usb_driver *driver =
-				to_usb_driver(intf->dev.driver);
-
-		dev_dbg(&intf->dev, "forced unbind\n");
-		usb_driver_release_interface(driver, intf);
-	}
+	if (intf->dev.driver)
+		usb_forced_unbind_intf(intf);
 
 	/* Try to rebind the interface */
 	if (!intf->dev.power.is_prepared) {
@@ -977,15 +972,13 @@ void usb_rebind_intf(struct usb_interface *intf)
 
 #ifdef CONFIG_PM
 
-#define DO_UNBIND	0
-#define DO_REBIND	1
-
-/* Unbind drivers for @udev's interfaces that don't support suspend/resume,
- * or rebind interfaces that have been unbound, according to @action.
+/* Unbind drivers for @udev's interfaces that don't support suspend/resume
+ * There is no check for reset_resume here because it can be determined
+ * only during resume whether reset_resume is needed.
  *
  * The caller must hold @udev's device lock.
  */
-static void do_unbind_rebind(struct usb_device *udev, int action)
+static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
 {
 	struct usb_host_config	*config;
 	int			i;
@@ -996,23 +989,53 @@ static void do_unbind_rebind(struct usb_device *udev, int action)
 	if (config) {
 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 			intf = config->interface[i];
-			switch (action) {
-			case DO_UNBIND:
-				if (intf->dev.driver) {
-					drv = to_usb_driver(intf->dev.driver);
-					if (!drv->suspend || !drv->resume)
-						usb_forced_unbind_intf(intf);
-				}
-				break;
-			case DO_REBIND:
-				if (intf->needs_binding)
-					usb_rebind_intf(intf);
-				break;
+
+			if (intf->dev.driver) {
+				drv = to_usb_driver(intf->dev.driver);
+				if (!drv->suspend || !drv->resume)
+					usb_forced_unbind_intf(intf);
 			}
 		}
 	}
 }
 
+/* Unbind drivers for @udev's interfaces that failed to support reset-resume.
+ * These interfaces have the needs_binding flag set by usb_resume_interface().
+ *
+ * The caller must hold @udev's device lock.
+ */
+static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
+{
+	struct usb_host_config	*config;
+	int			i;
+	struct usb_interface	*intf;
+
+	config = udev->actconfig;
+	if (config) {
+		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
+			intf = config->interface[i];
+			if (intf->dev.driver && intf->needs_binding)
+				usb_forced_unbind_intf(intf);
+		}
+	}
+}
+
+static void do_rebind_interfaces(struct usb_device *udev)
+{
+	struct usb_host_config	*config;
+	int			i;
+	struct usb_interface	*intf;
+
+	config = udev->actconfig;
+	if (config) {
+		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
+			intf = config->interface[i];
+			if (intf->needs_binding)
+				usb_rebind_intf(intf);
+		}
+	}
+}
+
 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_device_driver	*udriver;
@@ -1302,7 +1325,12 @@ int usb_suspend(struct device *dev, pm_message_t msg)
 {
 	struct usb_device	*udev = to_usb_device(dev);
 
-	do_unbind_rebind(udev, DO_UNBIND);
+	unbind_no_pm_drivers_interfaces(udev);
+
+	/* From now on we are sure all drivers support suspend/resume
+	 * but not necessarily reset_resume()
+	 * so we may still need to unbind and rebind upon resume
+	 */
 	choose_wakeup(udev, msg);
 	return usb_suspend_both(udev, msg);
 }
@@ -1313,15 +1341,20 @@ int usb_resume(struct device *dev, pm_message_t msg)
 	struct usb_device	*udev = to_usb_device(dev);
 	int			status;
 
-	/* For PM complete calls, all we do is rebind interfaces */
+	/* For PM complete calls, all we do is rebind interfaces
+	 * whose needs_binding flag is set
+	 */
 	if (msg.event == PM_EVENT_ON) {
 		if (udev->state != USB_STATE_NOTATTACHED)
-			do_unbind_rebind(udev, DO_REBIND);
+			do_rebind_interfaces(udev);
 		status = 0;
 
 	/* For all other calls, take the device back to full power and
 	 * tell the PM core in case it was autosuspended previously.
-	 * Unbind the interfaces that will need rebinding later.
+	 * Unbind the interfaces that will need rebinding later,
+	 * because they fail to support reset_resume.
+	 * (This can't be done in usb_resume_interface()
+         * above because it doesn't own the right set of locks.)
 	 */
 	} else {
 		status = usb_resume_both(udev, msg);
@@ -1329,7 +1362,7 @@ int usb_resume(struct device *dev, pm_message_t msg)
 			pm_runtime_disable(dev);
 			pm_runtime_set_active(dev);
 			pm_runtime_enable(dev);
-			do_unbind_rebind(udev, DO_REBIND);
+			unbind_no_reset_resume_drivers_interfaces(udev);
 		}
 	}