USB: convert to the runtime PM framework

This patch (as1329) converts the USB stack over to the PM core's
runtime PM framework.  This involves numerous changes throughout
usbcore, especially to hub.c and driver.c.  Perhaps the most notable
change is that CONFIG_USB_SUSPEND now depends on CONFIG_PM_RUNTIME
instead of CONFIG_PM.

Several fields in the usb_device and usb_interface structures are no
longer needed.  Some code which used to depend on CONFIG_USB_PM now
depends on CONFIG_USB_SUSPEND (requiring some rearrangement of header
files).

The only visible change in behavior should be that following a system
sleep (resume from RAM or resume from hibernation), autosuspended USB
devices will be resumed just like everything else.  They won't remain
suspended.  But if they aren't in use then they will naturally
autosuspend again in a few seconds.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/Kconfig

@@ -91,8 +91,8 @@ config USB_DYNAMIC_MINORS
 	  If you are unsure about this, say N here.
 
 config USB_SUSPEND
-	bool "USB selective suspend/resume and wakeup"
-	depends on USB && PM
+	bool "USB runtime power management (suspend/resume and wakeup)"
+	depends on USB && PM_RUNTIME
 	help
 	  If you say Y here, you can use driver calls or the sysfs
 	  "power/level" file to suspend or resume individual USB

drivers/usb/core/hcd.c

@@ -39,6 +39,7 @@
 #include <linux/platform_device.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/usb.h>
 
@@ -1858,6 +1859,10 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 	return status;
 }
 
+#endif	/* CONFIG_PM */
+
+#ifdef	CONFIG_USB_SUSPEND
+
 /* Workqueue routine for root-hub remote wakeup */
 static void hcd_resume_work(struct work_struct *work)
 {
@@ -1884,12 +1889,12 @@ void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
 
 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
 	if (hcd->rh_registered)
-		queue_work(ksuspend_usb_wq, &hcd->wakeup_work);
+		queue_work(pm_wq, &hcd->wakeup_work);
 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
 
-#endif
+#endif	/* CONFIG_USB_SUSPEND */
 
 /*-------------------------------------------------------------------------*/
 
@@ -2034,7 +2039,7 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
 	init_timer(&hcd->rh_timer);
 	hcd->rh_timer.function = rh_timer_func;
 	hcd->rh_timer.data = (unsigned long) hcd;
-#ifdef CONFIG_PM
+#ifdef CONFIG_USB_SUSPEND
 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
 #endif
 	mutex_init(&hcd->bandwidth_mutex);
@@ -2234,7 +2239,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
 	hcd->rh_registered = 0;
 	spin_unlock_irq (&hcd_root_hub_lock);
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_USB_SUSPEND
 	cancel_work_sync(&hcd->wakeup_work);
 #endif
 

drivers/usb/core/hcd.h

@@ -80,7 +80,7 @@ struct usb_hcd {
 
 	struct timer_list	rh_timer;	/* drives root-hub polling */
 	struct urb		*status_urb;	/* the current status urb */
-#ifdef CONFIG_PM
+#ifdef CONFIG_USB_SUSPEND
 	struct work_struct	wakeup_work;	/* for remote wakeup */
 #endif
 
@@ -464,16 +464,20 @@ extern int usb_find_interface_driver(struct usb_device *dev,
 #define usb_endpoint_out(ep_dir)	(!((ep_dir) & USB_DIR_IN))
 
 #ifdef CONFIG_PM
-extern void usb_hcd_resume_root_hub(struct usb_hcd *hcd);
 extern void usb_root_hub_lost_power(struct usb_device *rhdev);
 extern int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg);
 extern int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg);
+#endif /* CONFIG_PM */
+
+#ifdef CONFIG_USB_SUSPEND
+extern void usb_hcd_resume_root_hub(struct usb_hcd *hcd);
 #else
 static inline void usb_hcd_resume_root_hub(struct usb_hcd *hcd)
 {
 	return;
 }
-#endif /* CONFIG_PM */
+#endif /* CONFIG_USB_SUSPEND */
+
 
 /*
  * USB device fs stuff

drivers/usb/core/hub.c

@@ -22,6 +22,7 @@
 #include <linux/kthread.h>
 #include <linux/mutex.h>
 #include <linux/freezer.h>
+#include <linux/pm_runtime.h>
 
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
@@ -71,7 +72,6 @@ struct usb_hub {
 
 	unsigned		mA_per_port;	/* current for each child */
 
-	unsigned		init_done:1;
 	unsigned		limited_power:1;
 	unsigned		quiescing:1;
 	unsigned		disconnected:1;
@@ -820,7 +820,6 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 	}
  init3:
 	hub->quiescing = 0;
-	hub->init_done = 1;
 
 	status = usb_submit_urb(hub->urb, GFP_NOIO);
 	if (status < 0)
@@ -861,11 +860,6 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
 	int i;
 
 	cancel_delayed_work_sync(&hub->init_work);
-	if (!hub->init_done) {
-		hub->init_done = 1;
-		usb_autopm_put_interface_no_suspend(
-				to_usb_interface(hub->intfdev));
-	}
 
 	/* khubd and related activity won't re-trigger */
 	hub->quiescing = 1;
@@ -1405,10 +1399,8 @@ static void recursively_mark_NOTATTACHED(struct usb_device *udev)
 		if (udev->children[i])
 			recursively_mark_NOTATTACHED(udev->children[i]);
 	}
-	if (udev->state == USB_STATE_SUSPENDED) {
-		udev->discon_suspended = 1;
+	if (udev->state == USB_STATE_SUSPENDED)
 		udev->active_duration -= jiffies;
-	}
 	udev->state = USB_STATE_NOTATTACHED;
 }
 
@@ -1532,31 +1524,6 @@ static void update_address(struct usb_device *udev, int devnum)
 		udev->devnum = devnum;
 }
 
-#ifdef	CONFIG_USB_SUSPEND
-
-static void usb_stop_pm(struct usb_device *udev)
-{
-	/* Synchronize with the ksuspend thread to prevent any more
-	 * autosuspend requests from being submitted, and decrement
-	 * the parent's count of unsuspended children.
-	 */
-	usb_pm_lock(udev);
-	if (udev->parent && !udev->discon_suspended)
-		usb_autosuspend_device(udev->parent);
-	usb_pm_unlock(udev);
-
-	/* Stop any autosuspend or autoresume requests already submitted */
-	cancel_delayed_work_sync(&udev->autosuspend);
-	cancel_work_sync(&udev->autoresume);
-}
-
-#else
-
-static inline void usb_stop_pm(struct usb_device *udev)
-{ }
-
-#endif
-
 /**
  * usb_disconnect - disconnect a device (usbcore-internal)
  * @pdev: pointer to device being disconnected
@@ -1625,8 +1592,6 @@ void usb_disconnect(struct usb_device **pdev)
 	*pdev = NULL;
 	spin_unlock_irq(&device_state_lock);
 
-	usb_stop_pm(udev);
-
 	put_device(&udev->dev);
 }
 
@@ -1803,9 +1768,6 @@ int usb_new_device(struct usb_device *udev)
 	int err;
 
 	if (udev->parent) {
-		/* Increment the parent's count of unsuspended children */
-		usb_autoresume_device(udev->parent);
-
 		/* Initialize non-root-hub device wakeup to disabled;
 		 * device (un)configuration controls wakeup capable
 		 * sysfs power/wakeup controls wakeup enabled/disabled
@@ -1814,6 +1776,10 @@ int usb_new_device(struct usb_device *udev)
 		device_set_wakeup_enable(&udev->dev, 1);
 	}
 
+	/* Tell the runtime-PM framework the device is active */
+	pm_runtime_set_active(&udev->dev);
+	pm_runtime_enable(&udev->dev);
+
 	usb_detect_quirks(udev);
 	err = usb_enumerate_device(udev);	/* Read descriptors */
 	if (err < 0)
@@ -1844,7 +1810,8 @@ int usb_new_device(struct usb_device *udev)
 
 fail:
 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
-	usb_stop_pm(udev);
+	pm_runtime_disable(&udev->dev);
+	pm_runtime_set_suspended(&udev->dev);
 	return err;
 }
 
@@ -2408,8 +2375,11 @@ int usb_remote_wakeup(struct usb_device *udev)
 
 	if (udev->state == USB_STATE_SUSPENDED) {
 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
-		usb_mark_last_busy(udev);
-		status = usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
+		status = usb_autoresume_device(udev);
+		if (status == 0) {
+			/* Let the drivers do their thing, then... */
+			usb_autosuspend_device(udev);
+		}
 	}
 	return status;
 }
@@ -2446,11 +2416,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 	return status;
 }
 
-int usb_remote_wakeup(struct usb_device *udev)
-{
-	return 0;
-}
-
 #endif
 
 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
@@ -3268,7 +3233,7 @@ static void hub_events(void)
 		 * disconnected while waiting for the lock to succeed. */
 		usb_lock_device(hdev);
 		if (unlikely(hub->disconnected))
-			goto loop2;
+			goto loop_disconnected;
 
 		/* If the hub has died, clean up after it */
 		if (hdev->state == USB_STATE_NOTATTACHED) {
@@ -3428,7 +3393,7 @@ static void hub_events(void)
 		 * kick_khubd() and allow autosuspend.
 		 */
 		usb_autopm_put_interface(intf);
- loop2:
+ loop_disconnected:
 		usb_unlock_device(hdev);
 		kref_put(&hub->kref, hub_release);
 

drivers/usb/core/message.c

@@ -1843,7 +1843,6 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
 		intf->dev.dma_mask = dev->dev.dma_mask;
 		INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
 		device_initialize(&intf->dev);
-		mark_quiesced(intf);
 		dev_set_name(&intf->dev, "%d-%s:%d.%d",
 			dev->bus->busnum, dev->devpath,
 			configuration, alt->desc.bInterfaceNumber);

drivers/usb/core/usb.c

@@ -49,9 +49,6 @@ const char *usbcore_name = "usbcore";
 
 static int nousb;	/* Disable USB when built into kernel image */
 
-/* Workqueue for autosuspend and for remote wakeup of root hubs */
-struct workqueue_struct *ksuspend_usb_wq;
-
 #ifdef	CONFIG_USB_SUSPEND
 static int usb_autosuspend_delay = 2;		/* Default delay value,
 						 * in seconds */
@@ -264,23 +261,6 @@ static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 
 #ifdef	CONFIG_PM
 
-static int ksuspend_usb_init(void)
-{
-	/* This workqueue is supposed to be both freezable and
-	 * singlethreaded.  Its job doesn't justify running on more
-	 * than one CPU.
-	 */
-	ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
-	if (!ksuspend_usb_wq)
-		return -ENOMEM;
-	return 0;
-}
-
-static void ksuspend_usb_cleanup(void)
-{
-	destroy_workqueue(ksuspend_usb_wq);
-}
-
 /* USB device Power-Management thunks.
  * There's no need to distinguish here between quiescing a USB device
  * and powering it down; the generic_suspend() routine takes care of
@@ -296,7 +276,7 @@ static int usb_dev_prepare(struct device *dev)
 static void usb_dev_complete(struct device *dev)
 {
 	/* Currently used only for rebinding interfaces */
-	usb_resume(dev, PMSG_RESUME);	/* Message event is meaningless */
+	usb_resume(dev, PMSG_ON);	/* FIXME: change to PMSG_COMPLETE */
 }
 
 static int usb_dev_suspend(struct device *dev)
@@ -342,9 +322,7 @@ static const struct dev_pm_ops usb_device_pm_ops = {
 
 #else
 
-#define ksuspend_usb_init()	0
-#define ksuspend_usb_cleanup()	do {} while (0)
-#define usb_device_pm_ops	(*(struct dev_pm_ops *)0)
+#define usb_device_pm_ops	(*(struct dev_pm_ops *) NULL)
 
 #endif	/* CONFIG_PM */
 
@@ -472,9 +450,6 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
 	INIT_LIST_HEAD(&dev->filelist);
 
 #ifdef	CONFIG_PM
-	mutex_init(&dev->pm_mutex);
-	INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
-	INIT_WORK(&dev->autoresume, usb_autoresume_work);
 	dev->autosuspend_delay = usb_autosuspend_delay * HZ;
 	dev->connect_time = jiffies;
 	dev->active_duration = -jiffies;
@@ -1117,9 +1092,6 @@ static int __init usb_init(void)
 	if (retval)
 		goto out;
 
-	retval = ksuspend_usb_init();
-	if (retval)
-		goto out;
 	retval = bus_register(&usb_bus_type);
 	if (retval)
 		goto bus_register_failed;
@@ -1159,7 +1131,7 @@ static int __init usb_init(void)
 bus_notifier_failed:
 	bus_unregister(&usb_bus_type);
 bus_register_failed:
-	ksuspend_usb_cleanup();
+	usb_debugfs_cleanup();
 out:
 	return retval;
 }
@@ -1181,7 +1153,6 @@ static void __exit usb_exit(void)
 	usb_hub_cleanup();
 	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
 	bus_unregister(&usb_bus_type);
-	ksuspend_usb_cleanup();
 	usb_debugfs_cleanup();
 }
 

drivers/usb/core/usb.h

@@ -55,25 +55,8 @@ extern void usb_major_cleanup(void);
 extern int usb_suspend(struct device *dev, pm_message_t msg);
 extern int usb_resume(struct device *dev, pm_message_t msg);
 
-extern void usb_autosuspend_work(struct work_struct *work);
-extern void usb_autoresume_work(struct work_struct *work);
 extern int usb_port_suspend(struct usb_device *dev, pm_message_t msg);
 extern int usb_port_resume(struct usb_device *dev, pm_message_t msg);
-extern int usb_external_suspend_device(struct usb_device *udev,
-		pm_message_t msg);
-extern int usb_external_resume_device(struct usb_device *udev,
-		pm_message_t msg);
-extern int usb_remote_wakeup(struct usb_device *dev);
-
-static inline void usb_pm_lock(struct usb_device *udev)
-{
-	mutex_lock_nested(&udev->pm_mutex, udev->level);
-}
-
-static inline void usb_pm_unlock(struct usb_device *udev)
-{
-	mutex_unlock(&udev->pm_mutex);
-}
 
 #else
 
@@ -87,14 +70,6 @@ static inline int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 	return 0;
 }
 
-static inline int usb_remote_wakeup(struct usb_device *udev)
-{
-	return 0;
-}
-
-static inline void usb_pm_lock(struct usb_device *udev) {}
-static inline void usb_pm_unlock(struct usb_device *udev) {}
-
 #endif
 
 #ifdef CONFIG_USB_SUSPEND
@@ -102,6 +77,7 @@ static inline void usb_pm_unlock(struct usb_device *udev) {}
 extern void usb_autosuspend_device(struct usb_device *udev);
 extern void usb_try_autosuspend_device(struct usb_device *udev);
 extern int usb_autoresume_device(struct usb_device *udev);
+extern int usb_remote_wakeup(struct usb_device *dev);
 
 #else
 
@@ -112,9 +88,13 @@ static inline int usb_autoresume_device(struct usb_device *udev)
 	return 0;
 }
 
+static inline int usb_remote_wakeup(struct usb_device *udev)
+{
+	return 0;
+}
+
 #endif
 
-extern struct workqueue_struct *ksuspend_usb_wq;
 extern struct bus_type usb_bus_type;
 extern struct device_type usb_device_type;
 extern struct device_type usb_if_device_type;
@@ -144,23 +124,6 @@ static inline int is_usb_device_driver(struct device_driver *drv)
 			for_devices;
 }
 
-/* Interfaces and their "power state" are owned by usbcore */
-
-static inline void mark_active(struct usb_interface *f)
-{
-	f->is_active = 1;
-}
-
-static inline void mark_quiesced(struct usb_interface *f)
-{
-	f->is_active = 0;
-}
-
-static inline int is_active(const struct usb_interface *f)
-{
-	return f->is_active;
-}
-
 
 /* for labeling diagnostics */
 extern const char *usbcore_name;

drivers/usb/misc/usbtest.c

@@ -1580,10 +1580,6 @@ usbtest_ioctl (struct usb_interface *intf, unsigned int code, void *buf)
 		return -ERESTARTSYS;
 
 	/* FIXME: What if a system sleep starts while a test is running? */
-	if (!intf->is_active) {
-		mutex_unlock(&dev->lock);
-		return -EHOSTUNREACH;
-	}
 
 	/* some devices, like ez-usb default devices, need a non-default
 	 * altsetting to have any active endpoints.  some tests change

include/linux/usb.h

@@ -122,7 +122,6 @@ enum usb_interface_condition {
  *	number from the USB core by calling usb_register_dev().
  * @condition: binding state of the interface: not bound, binding
  *	(in probe()), bound to a driver, or unbinding (in disconnect())
- * @is_active: flag set when the interface is bound and not suspended.
  * @sysfs_files_created: sysfs attributes exist
  * @ep_devs_created: endpoint child pseudo-devices exist
  * @unregistering: flag set when the interface is being unregistered
@@ -135,8 +134,7 @@ enum usb_interface_condition {
  * @dev: driver model's view of this device
  * @usb_dev: if an interface is bound to the USB major, this will point
  *	to the sysfs representation for that device.
- * @pm_usage_cnt: PM usage counter for this interface; autosuspend is not
- *	allowed unless the counter is 0.
+ * @pm_usage_cnt: PM usage counter for this interface
  * @reset_ws: Used for scheduling resets from atomic context.
  * @reset_running: set to 1 if the interface is currently running a
  *      queued reset so that usb_cancel_queued_reset() doesn't try to
@@ -184,7 +182,6 @@ struct usb_interface {
 	int minor;			/* minor number this interface is
 					 * bound to */
 	enum usb_interface_condition condition;		/* state of binding */
-	unsigned is_active:1;		/* the interface is not suspended */
 	unsigned sysfs_files_created:1;	/* the sysfs attributes exist */
 	unsigned ep_devs_created:1;	/* endpoint "devices" exist */
 	unsigned unregistering:1;	/* unregistration is in progress */
@@ -401,7 +398,6 @@ struct usb_tt;
  * @portnum: parent port number (origin 1)
  * @level: number of USB hub ancestors
  * @can_submit: URBs may be submitted
- * @discon_suspended: disconnected while suspended
  * @persist_enabled:  USB_PERSIST enabled for this device
  * @have_langid: whether string_langid is valid
  * @authorized: policy has said we can use it;
@@ -421,20 +417,15 @@ struct usb_tt;
  * @usbfs_dentry: usbfs dentry entry for the device
  * @maxchild: number of ports if hub
  * @children: child devices - USB devices that are attached to this hub
- * @pm_usage_cnt: usage counter for autosuspend
  * @quirks: quirks of the whole device
  * @urbnum: number of URBs submitted for the whole device
  * @active_duration: total time device is not suspended
- * @autosuspend: for delayed autosuspends
- * @autoresume: for autoresumes requested while in_interrupt
- * @pm_mutex: protects PM operations
  * @last_busy: time of last use
  * @autosuspend_delay: in jiffies
  * @connect_time: time device was first connected
  * @do_remote_wakeup:  remote wakeup should be enabled
  * @reset_resume: needs reset instead of resume
  * @autosuspend_disabled: autosuspend disabled by the user
- * @skip_sys_resume: skip the next system resume
  * @wusb_dev: if this is a Wireless USB device, link to the WUSB
  *	specific data for the device.
  * @slot_id: Slot ID assigned by xHCI
@@ -475,7 +466,6 @@ struct usb_device {
 	u8 level;
 
 	unsigned can_submit:1;
-	unsigned discon_suspended:1;
 	unsigned persist_enabled:1;
 	unsigned have_langid:1;
 	unsigned authorized:1;
@@ -499,17 +489,12 @@ struct usb_device {
 	int maxchild;
 	struct usb_device *children[USB_MAXCHILDREN];
 
-	int pm_usage_cnt;
 	u32 quirks;
 	atomic_t urbnum;
 
 	unsigned long active_duration;
 
 #ifdef CONFIG_PM
-	struct delayed_work autosuspend;
-	struct work_struct autoresume;
-	struct mutex pm_mutex;
-
 	unsigned long last_busy;
 	int autosuspend_delay;
 	unsigned long connect_time;
@@ -517,7 +502,6 @@ struct usb_device {
 	unsigned do_remote_wakeup:1;
 	unsigned reset_resume:1;
 	unsigned autosuspend_disabled:1;
-	unsigned skip_sys_resume:1;
 #endif
 	struct wusb_dev *wusb_dev;
 	int slot_id;
@@ -549,17 +533,8 @@ extern int usb_autopm_get_interface(struct usb_interface *intf);
 extern void usb_autopm_put_interface(struct usb_interface *intf);
 extern int usb_autopm_get_interface_async(struct usb_interface *intf);
 extern void usb_autopm_put_interface_async(struct usb_interface *intf);
-
-static inline void usb_autopm_get_interface_no_resume(
-		struct usb_interface *intf)
-{
-	atomic_inc(&intf->pm_usage_cnt);
-}
-static inline void usb_autopm_put_interface_no_suspend(
-		struct usb_interface *intf)
-{
-	atomic_dec(&intf->pm_usage_cnt);
-}
+extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf);
+extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf);
 
 static inline void usb_mark_last_busy(struct usb_device *udev)
 {