Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / usb / core / driver.c

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 6eab440e1542e450f7733fb4cbbf35b1b1044313..2cdd5079ae78b4338393c703c3e98c7e6d68885a 100644 (file)
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -953,8 +953,7 @@ 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)
 {
@@ -967,16 +966,37 @@ 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;
 
@@ -993,68 +1013,66 @@ 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);
+                       }
                }
        }
 }
@@ -1379,7 +1397,7 @@ 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;
 }
 
@@ -1401,7 +1419,7 @@ 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
@@ -1736,10 +1754,13 @@ 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;
 }