+
+/* Forced unbinding of a USB interface driver, either because
+ * it doesn't support pre_reset/post_reset/reset_resume or
+ * because it doesn't support suspend/resume.
+ *
+ * The caller must hold @intf's device's lock, but not its pm_mutex
+ * and not @intf->dev.sem.
+ */
+void usb_forced_unbind_intf(struct usb_interface *intf)
+{
+ struct usb_driver *driver = to_usb_driver(intf->dev.driver);
+
+ dev_dbg(&intf->dev, "forced unbind\n");
+ usb_driver_release_interface(driver, intf);
+
+ /* Mark the interface for later rebinding */
+ intf->needs_binding = 1;
+}
+
+/* Delayed forced unbinding of a USB interface driver and scan
+ * for rebinding.
+ *
+ * The caller must hold @intf's device's lock, but not its pm_mutex
+ * and not @intf->dev.sem.
+ *
+ * FIXME: The caller must block system sleep transitions.
+ */
+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);
+ }
+
+ /* Try to rebind the interface */
+ intf->needs_binding = 0;
+ rc = device_attach(&intf->dev);
+ if (rc < 0)
+ dev_warn(&intf->dev, "rebind failed: %d\n", rc);
+}
+
+#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.
+ *
+ * The caller must hold @udev's device lock.
+ * FIXME: For rebinds, the caller must block system sleep transitions.
+ */
+static void do_unbind_rebind(struct usb_device *udev, int action)
+{
+ struct usb_host_config *config;
+ int i;
+ struct usb_interface *intf;
+ struct usb_driver *drv;
+
+ config = udev->actconfig;
+ 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) {
+
+ /* FIXME: The next line is needed because we are going to probe
+ * the interface, but as far as the PM core is concerned the
+ * interface is still suspended. The problem wouldn't exist
+ * if we could rebind the interface during the interface's own
+ * resume() call, but at the time the usb_device isn't locked!
+ *
+ * The real solution will be to carry this out during the device's
+ * complete() callback. Until that is implemented, we have to
+ * use this hack.
+ */
+// intf->dev.power.sleeping = 0;
+
+ usb_rebind_intf(intf);
+ }
+ break;
+ }
+ }
+ }
+}
+