1 files changed, 62 insertions, 41 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index ab90a0156828..39c7cd6ffa4b 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -990,8 +990,7 @@ EXPORT_SYMBOL_GPL(usb_deregister);
  * 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.
+ * The caller must hold @intf's device's lock, but not @intf's lock.
  */
 void usb_forced_unbind_intf(struct usb_interface *intf)
 {
@@ -1004,16 +1003,37 @@ void usb_forced_unbind_intf(struct usb_interface *intf)
 	intf->needs_binding = 1;
 }
 
+/*
+ * Unbind drivers for @udev's marked interfaces.  These interfaces have
+ * the needs_binding flag set, for example by usb_resume_interface().
+ *
+ * The caller must hold @udev's device lock.
+ */
+static void unbind_marked_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);
+		}
+	}
+}
+
 /* 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.
+ * The caller must hold @intf's device's lock, but not @intf's lock.
  *
  * Note: Rebinds will be skipped if a system sleep transition is in
  * progress and the PM "complete" callback hasn't occurred yet.
  */
-void usb_rebind_intf(struct usb_interface *intf)
+static void usb_rebind_intf(struct usb_interface *intf)
 {
 	int rc;
 
@@ -1030,68 +1050,66 @@ void usb_rebind_intf(struct usb_interface *intf)
 	}
 }
 
-#ifdef CONFIG_PM
-
-/* 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.
+/*
+ * Rebind drivers to @udev's marked interfaces.  These interfaces have
+ * the needs_binding flag set.
  *
  * The caller must hold @udev's device lock.
  */
-static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
+static void rebind_marked_interfaces(struct usb_device *udev)
 {
 	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];
-
-			if (intf->dev.driver) {
-				drv = to_usb_driver(intf->dev.driver);
-				if (!drv->suspend || !drv->resume)
-					usb_forced_unbind_intf(intf);
-			}
+			if (intf->needs_binding)
+				usb_rebind_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().
+/*
+ * Unbind all of @udev's marked interfaces and then rebind all of them.
+ * This ordering is necessary because some drivers claim several interfaces
+ * when they are first probed.
  *
  * The caller must hold @udev's device lock.
  */
-static void unbind_no_reset_resume_drivers_interfaces(struct usb_device *udev)
+void usb_unbind_and_rebind_marked_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);
-		}
-	}
+	unbind_marked_interfaces(udev);
+	rebind_marked_interfaces(udev);
 }
 
-static void do_rebind_interfaces(struct usb_device *udev)
+#ifdef CONFIG_PM
+
+/* 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 unbind_no_pm_drivers_interfaces(struct usb_device *udev)
 {
 	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];
-			if (intf->needs_binding)
-				usb_rebind_intf(intf);
+
+			if (intf->dev.driver) {
+				drv = to_usb_driver(intf->dev.driver);
+				if (!drv->suspend || !drv->resume)
+					usb_forced_unbind_intf(intf);
+			}
 		}
 	}
 }
@@ -1420,7 +1438,7 @@ int usb_resume_complete(struct device *dev)
 	 * whose needs_binding flag is set
 	 */
 	if (udev->state != USB_STATE_NOTATTACHED)
-		do_rebind_interfaces(udev);
+		rebind_marked_interfaces(udev);
 	return 0;
 }
 
@@ -1442,7 +1460,7 @@ int usb_resume(struct device *dev, pm_message_t msg)
 		pm_runtime_disable(dev);
 		pm_runtime_set_active(dev);
 		pm_runtime_enable(dev);
-		unbind_no_reset_resume_drivers_interfaces(udev);
+		unbind_marked_interfaces(udev);
 	}
 
 	/* Avoid PM error messages for devices disconnected while suspended
@@ -1783,10 +1801,13 @@ int usb_runtime_suspend(struct device *dev)
 	if (status == -EAGAIN || status == -EBUSY)
 		usb_mark_last_busy(udev);
 
-	/* The PM core reacts badly unless the return code is 0,
-	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error.
+	/*
+	 * The PM core reacts badly unless the return code is 0,
+	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
+	 * (except for root hubs, because they don't suspend through
+	 * an upstream port like other USB devices).
 	 */
-	if (status != 0)
+	if (status != 0 && udev->parent)
 		return -EBUSY;
 	return status;
 }