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>

1 files changed, 368 insertions, 477 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 638d546..6850ec6 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -25,7 +25,7 @@
 #include <linux/device.h>
 #include <linux/usb.h>
 #include <linux/usb/quirks.h>
-#include <linux/workqueue.h>
+#include <linux/pm_runtime.h>
 #include "hcd.h"
 #include "usb.h"
 
@@ -221,7 +221,7 @@ static int usb_probe_device(struct device *dev)
 {
 	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
 	struct usb_device *udev = to_usb_device(dev);
-	int error = -ENODEV;
+	int error = 0;
 
 	dev_dbg(dev, "%s\n", __func__);
 
@@ -230,18 +230,23 @@ static int usb_probe_device(struct device *dev)
 	/* The device should always appear to be in use
 	 * unless the driver suports autosuspend.
 	 */
-	udev->pm_usage_cnt = !(udriver->supports_autosuspend);
+	if (!udriver->supports_autosuspend)
+		error = usb_autoresume_device(udev);
 
-	error = udriver->probe(udev);
+	if (!error)
+		error = udriver->probe(udev);
 	return error;
 }
 
 /* called from driver core with dev locked */
 static int usb_unbind_device(struct device *dev)
 {
+	struct usb_device *udev = to_usb_device(dev);
 	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
 
-	udriver->disconnect(to_usb_device(dev));
+	udriver->disconnect(udev);
+	if (!udriver->supports_autosuspend)
+		usb_autosuspend_device(udev);
 	return 0;
 }
 
@@ -293,17 +298,16 @@ static int usb_probe_interface(struct device *dev)
 	if (error)
 		return error;
 
-	/* Interface "power state" doesn't correspond to any hardware
-	 * state whatsoever.  We use it to record when it's bound to
-	 * a driver that may start I/0:  it's not frozen/quiesced.
-	 */
-	mark_active(intf);
 	intf->condition = USB_INTERFACE_BINDING;
 
-	/* The interface should always appear to be in use
-	 * unless the driver suports autosuspend.
+	/* Bound interfaces are initially active.  They are
+	 * runtime-PM-enabled only if the driver has autosuspend support.
+	 * They are sensitive to their children's power states.
 	 */
-	atomic_set(&intf->pm_usage_cnt, !driver->supports_autosuspend);
+	pm_runtime_set_active(dev);
+	pm_suspend_ignore_children(dev, false);
+	if (driver->supports_autosuspend)
+		pm_runtime_enable(dev);
 
 	/* Carry out a deferred switch to altsetting 0 */
 	if (intf->needs_altsetting0) {
@@ -323,10 +327,14 @@ static int usb_probe_interface(struct device *dev)
 	return error;
 
  err:
-	mark_quiesced(intf);
 	intf->needs_remote_wakeup = 0;
 	intf->condition = USB_INTERFACE_UNBOUND;
 	usb_cancel_queued_reset(intf);
+
+	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+
 	usb_autosuspend_device(udev);
 	return error;
 }
@@ -376,9 +384,17 @@ static int usb_unbind_interface(struct device *dev)
 	usb_set_intfdata(intf, NULL);
 
 	intf->condition = USB_INTERFACE_UNBOUND;
-	mark_quiesced(intf);
 	intf->needs_remote_wakeup = 0;
 
+	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+
+	/* Undo any residual pm_autopm_get_interface_* calls */
+	for (r = atomic_read(&intf->pm_usage_cnt); r > 0; --r)
+		usb_autopm_put_interface_no_suspend(intf);
+	atomic_set(&intf->pm_usage_cnt, 0);
+
 	if (!error)
 		usb_autosuspend_device(udev);
 
@@ -409,7 +425,6 @@ int usb_driver_claim_interface(struct usb_driver *driver,
 				struct usb_interface *iface, void *priv)
 {
 	struct device *dev = &iface->dev;
-	struct usb_device *udev = interface_to_usbdev(iface);
 	int retval = 0;
 
 	if (dev->driver)
@@ -419,11 +434,16 @@ int usb_driver_claim_interface(struct usb_driver *driver,
 	usb_set_intfdata(iface, priv);
 	iface->needs_binding = 0;
 
-	usb_pm_lock(udev);
 	iface->condition = USB_INTERFACE_BOUND;
-	mark_active(iface);
-	atomic_set(&iface->pm_usage_cnt, !driver->supports_autosuspend);
-	usb_pm_unlock(udev);
+
+	/* Bound interfaces are initially active.  They are
+	 * runtime-PM-enabled only if the driver has autosuspend support.
+	 * They are sensitive to their children's power states.
+	 */
+	pm_runtime_set_active(dev);
+	pm_suspend_ignore_children(dev, false);
+	if (driver->supports_autosuspend)
+		pm_runtime_enable(dev);
 
 	/* if interface was already added, bind now; else let
 	 * the future device_add() bind it, bypassing probe()
@@ -982,7 +1002,6 @@ static void do_unbind_rebind(struct usb_device *udev, int action)
 	}
 }
 
-/* Caller has locked udev's pm_mutex */
 static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_device_driver	*udriver;
@@ -1006,7 +1025,6 @@ static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
 	return status;
 }
 
-/* Caller has locked udev's pm_mutex */
 static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_device_driver	*udriver;
@@ -1040,27 +1058,20 @@ static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
 	return status;
 }
 
-/* Caller has locked intf's usb_device's pm mutex */
 static int usb_suspend_interface(struct usb_device *udev,
 		struct usb_interface *intf, pm_message_t msg)
 {
 	struct usb_driver	*driver;
 	int			status = 0;
 
-	/* with no hardware, USB interfaces only use FREEZE and ON states */
-	if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
-		goto done;
-
-	/* This can happen; see usb_driver_release_interface() */
-	if (intf->condition == USB_INTERFACE_UNBOUND)
+	if (udev->state == USB_STATE_NOTATTACHED ||
+			intf->condition == USB_INTERFACE_UNBOUND)
 		goto done;
 	driver = to_usb_driver(intf->dev.driver);
 
 	if (driver->suspend) {
 		status = driver->suspend(intf, msg);
-		if (status == 0)
-			mark_quiesced(intf);
-		else if (!(msg.event & PM_EVENT_AUTO))
+		if (status && !(msg.event & PM_EVENT_AUTO))
 			dev_err(&intf->dev, "%s error %d\n",
 					"suspend", status);
 	} else {
@@ -1068,7 +1079,6 @@ static int usb_suspend_interface(struct usb_device *udev,
 		intf->needs_binding = 1;
 		dev_warn(&intf->dev, "no %s for driver %s?\n",
 				"suspend", driver->name);
-		mark_quiesced(intf);
 	}
 
  done:
@@ -1076,14 +1086,13 @@ static int usb_suspend_interface(struct usb_device *udev,
 	return status;
 }
 
-/* Caller has locked intf's usb_device's pm_mutex */
 static int usb_resume_interface(struct usb_device *udev,
 		struct usb_interface *intf, pm_message_t msg, int reset_resume)
 {
 	struct usb_driver	*driver;
 	int			status = 0;
 
-	if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
+	if (udev->state == USB_STATE_NOTATTACHED)
 		goto done;
 
 	/* Don't let autoresume interfere with unbinding */
@@ -1134,90 +1143,11 @@ static int usb_resume_interface(struct usb_device *udev,
 
 done:
 	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
-	if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
-		mark_active(intf);
 
 	/* Later we will unbind the driver and/or reprobe, if necessary */
 	return status;
 }
 
-#ifdef	CONFIG_USB_SUSPEND
-
-/* Internal routine to check whether we may autosuspend a device. */
-static int autosuspend_check(struct usb_device *udev, int reschedule)
-{
-	int			i;
-	struct usb_interface	*intf;
-	unsigned long		suspend_time, j;
-
-	/* For autosuspend, fail fast if anything is in use or autosuspend
-	 * is disabled.  Also fail if any interfaces require remote wakeup
-	 * but it isn't available.
-	 */
-	if (udev->pm_usage_cnt > 0)
-		return -EBUSY;
-	if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
-		return -EPERM;
-
-	suspend_time = udev->last_busy + udev->autosuspend_delay;
-	if (udev->actconfig) {
-		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
-			intf = udev->actconfig->interface[i];
-			if (!is_active(intf))
-				continue;
-			if (atomic_read(&intf->pm_usage_cnt) > 0)
-				return -EBUSY;
-			if (intf->needs_remote_wakeup &&
-					!udev->do_remote_wakeup) {
-				dev_dbg(&udev->dev, "remote wakeup needed "
-						"for autosuspend\n");
-				return -EOPNOTSUPP;
-			}
-
-			/* Don't allow autosuspend if the device will need
-			 * a reset-resume and any of its interface drivers
-			 * doesn't include support.
-			 */
-			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
-				struct usb_driver *driver;
-
-				driver = to_usb_driver(intf->dev.driver);
-				if (!driver->reset_resume ||
-				    intf->needs_remote_wakeup)
-					return -EOPNOTSUPP;
-			}
-		}
-	}
-
-	/* If everything is okay but the device hasn't been idle for long
-	 * enough, queue a delayed autosuspend request.  If the device
-	 * _has_ been idle for long enough and the reschedule flag is set,
-	 * likewise queue a delayed (1 second) autosuspend request.
-	 */
-	j = jiffies;
-	if (time_before(j, suspend_time))
-		reschedule = 1;
-	else
-		suspend_time = j + HZ;
-	if (reschedule) {
-		if (!timer_pending(&udev->autosuspend.timer)) {
-			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
-				round_jiffies_up_relative(suspend_time - j));
-		}
-		return -EAGAIN;
-	}
-	return 0;
-}
-
-#else
-
-static inline int autosuspend_check(struct usb_device *udev, int reschedule)
-{
-	return 0;
-}
-
-#endif	/* CONFIG_USB_SUSPEND */
-
 /**
  * usb_suspend_both - suspend a USB device and its interfaces
  * @udev: the usb_device to suspend
@@ -1229,27 +1159,12 @@ static inline int autosuspend_check(struct usb_device *udev, int reschedule)
  * all the interfaces which were suspended are resumed so that they remain
  * in the same state as the device.
  *
- * If an autosuspend is in progress the routine checks first to make sure
- * that neither the device itself or any of its active interfaces is in use
- * (pm_usage_cnt is greater than 0).  If they are, the autosuspend fails.
- *
- * If the suspend succeeds, the routine recursively queues an autosuspend
- * request for @udev's parent device, thereby propagating the change up
- * the device tree.  If all of the parent's children are now suspended,
- * the parent will autosuspend in turn.
- *
- * The suspend method calls are subject to mutual exclusion under control
- * of @udev's pm_mutex.  Many of these calls are also under the protection
- * of @udev's device lock (including all requests originating outside the
- * USB subsystem), but autosuspend requests generated by a child device or
- * interface driver may not be.  Usbcore will insure that the method calls
- * do not arrive during bind, unbind, or reset operations.  However, drivers
- * must be prepared to handle suspend calls arriving at unpredictable times.
- * The only way to block such calls is to do an autoresume (preventing
- * autosuspends) while holding @udev's device lock (preventing outside
- * suspends).
- *
- * The caller must hold @udev->pm_mutex.
+ * Autosuspend requests originating from a child device or an interface
+ * driver may be made without the protection of @udev's device lock, but
+ * all other suspend calls will hold the lock.  Usbcore will insure that
+ * method calls do not arrive during bind, unbind, or reset operations.
+ * However drivers must be prepared to handle suspend calls arriving at
+ * unpredictable times.
  *
  * This routine can run only in process context.
  */
@@ -1258,20 +1173,11 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
 	int			status = 0;
 	int			i = 0;
 	struct usb_interface	*intf;
-	struct usb_device	*parent = udev->parent;
 
 	if (udev->state == USB_STATE_NOTATTACHED ||
 			udev->state == USB_STATE_SUSPENDED)
 		goto done;
 
-	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
-
-	if (msg.event & PM_EVENT_AUTO) {
-		status = autosuspend_check(udev, 0);
-		if (status < 0)
-			goto done;
-	}
-
 	/* Suspend all the interfaces and then udev itself */
 	if (udev->actconfig) {
 		for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
@@ -1286,35 +1192,21 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
 
 	/* If the suspend failed, resume interfaces that did get suspended */
 	if (status != 0) {
-		pm_message_t msg2;
-
-		msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
+		msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
 		while (--i >= 0) {
 			intf = udev->actconfig->interface[i];
-			usb_resume_interface(udev, intf, msg2, 0);
+			usb_resume_interface(udev, intf, msg, 0);
 		}
 
-		/* Try another autosuspend when the interfaces aren't busy */
-		if (msg.event & PM_EVENT_AUTO)
-			autosuspend_check(udev, status == -EBUSY);
-
-	/* If the suspend succeeded then prevent any more URB submissions,
-	 * flush any outstanding URBs, and propagate the suspend up the tree.
+	/* If the suspend succeeded then prevent any more URB submissions
+	 * and flush any outstanding URBs.
 	 */
 	} else {
-		cancel_delayed_work(&udev->autosuspend);
 		udev->can_submit = 0;
 		for (i = 0; i < 16; ++i) {
 			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
 			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
 		}
-
-		/* If this is just a FREEZE or a PRETHAW, udev might
-		 * not really be suspended.  Only true suspends get
-		 * propagated up the device tree.
-		 */
-		if (parent && udev->state == USB_STATE_SUSPENDED)
-			usb_autosuspend_device(parent);
 	}
 
  done:
@@ -1331,23 +1223,12 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
  * the resume method for @udev and then calls the resume methods for all
  * the interface drivers in @udev.
  *
- * Before starting the resume, the routine calls itself recursively for
- * the parent device of @udev, thereby propagating the change up the device
- * tree and assuring that @udev will be able to resume.  If the parent is
- * unable to resume successfully, the routine fails.
- *
- * The resume method calls are subject to mutual exclusion under control
- * of @udev's pm_mutex.  Many of these calls are also under the protection
- * of @udev's device lock (including all requests originating outside the
- * USB subsystem), but autoresume requests generated by a child device or
- * interface driver may not be.  Usbcore will insure that the method calls
- * do not arrive during bind, unbind, or reset operations.  However, drivers
- * must be prepared to handle resume calls arriving at unpredictable times.
- * The only way to block such calls is to do an autoresume (preventing
- * other autoresumes) while holding @udev's device lock (preventing outside
- * resumes).
- *
- * The caller must hold @udev->pm_mutex.
+ * Autoresume requests originating from a child device or an interface
+ * driver may be made without the protection of @udev's device lock, but
+ * all other resume calls will hold the lock.  Usbcore will insure that
+ * method calls do not arrive during bind, unbind, or reset operations.
+ * However drivers must be prepared to handle resume calls arriving at
+ * unpredictable times.
  *
  * This routine can run only in process context.
  */
@@ -1356,48 +1237,18 @@ static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
 	int			status = 0;
 	int			i;
 	struct usb_interface	*intf;
-	struct usb_device	*parent = udev->parent;
 
-	cancel_delayed_work(&udev->autosuspend);
 	if (udev->state == USB_STATE_NOTATTACHED) {
 		status = -ENODEV;
 		goto done;
 	}
 	udev->can_submit = 1;
 
-	/* Propagate the resume up the tree, if necessary */
-	if (udev->state == USB_STATE_SUSPENDED) {
-		if (parent) {
-			status = usb_autoresume_device(parent);
-			if (status == 0) {
-				status = usb_resume_device(udev, msg);
-				if (status || udev->state ==
-						USB_STATE_NOTATTACHED) {
-					usb_autosuspend_device(parent);
-
-					/* It's possible usb_resume_device()
-					 * failed after the port was
-					 * unsuspended, causing udev to be
-					 * logically disconnected.  We don't
-					 * want usb_disconnect() to autosuspend
-					 * the parent again, so tell it that
-					 * udev disconnected while still
-					 * suspended. */
-					if (udev->state ==
-							USB_STATE_NOTATTACHED)
-						udev->discon_suspended = 1;
-				}
-			}
-		} else {
-
-			/* We can't progagate beyond the USB subsystem,
-			 * so if a root hub's controller is suspended
-			 * then we're stuck. */
-			status = usb_resume_device(udev, msg);
-		}
-	} else if (udev->reset_resume)
+	/* Resume the device */
+	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
 		status = usb_resume_device(udev, msg);
 
+	/* Resume the interfaces */
 	if (status == 0 && udev->actconfig) {
 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
 			intf = udev->actconfig->interface[i];
@@ -1413,104 +1264,46 @@ static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
 	return status;
 }
 
-/**
- * usb_external_suspend_device - external suspend of a USB device and its interfaces
- * @udev: the usb_device to suspend
- * @msg: Power Management message describing this state transition
- *
- * This routine handles external suspend requests: ones not generated
- * internally by a USB driver (autosuspend) but rather coming from the user
- * (via sysfs) or the PM core (system sleep).  The suspend will be carried
- * out regardless of @udev's usage counter or those of its interfaces,
- * and regardless of whether or not remote wakeup is enabled.  Of course,
- * interface drivers still have the option of failing the suspend (if
- * there are unsuspended children, for example).
- *
- * The caller must hold @udev's device lock.
- */
-int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
-{
-	int	status;
-
-	do_unbind_rebind(udev, DO_UNBIND);
-	usb_pm_lock(udev);
-	status = usb_suspend_both(udev, msg);
-	usb_pm_unlock(udev);
-	return status;
-}
-
-/**
- * usb_external_resume_device - external resume of a USB device and its interfaces
- * @udev: the usb_device to resume
- * @msg: Power Management message describing this state transition
- *
- * This routine handles external resume requests: ones not generated
- * internally by a USB driver (autoresume) but rather coming from the user
- * (via sysfs), the PM core (system resume), or the device itself (remote
- * wakeup).  @udev's usage counter is unaffected.
- *
- * The caller must hold @udev's device lock.
- */
-int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
-{
-	int	status;
-
-	usb_pm_lock(udev);
-	status = usb_resume_both(udev, msg);
-	udev->last_busy = jiffies;
-	usb_pm_unlock(udev);
-	if (status == 0)
-		do_unbind_rebind(udev, DO_REBIND);
-
-	/* Now that the device is awake, we can start trying to autosuspend
-	 * it again. */
-	if (status == 0)
-		usb_try_autosuspend_device(udev);
-	return status;
-}
-
+/* The device lock is held by the PM core */
 int usb_suspend(struct device *dev, pm_message_t msg)
 {
-	struct usb_device	*udev;
-
-	udev = to_usb_device(dev);
+	struct usb_device	*udev = to_usb_device(dev);
 
-	/* If udev is already suspended, we can skip this suspend and
-	 * we should also skip the upcoming system resume.  High-speed
-	 * root hubs are an exception; they need to resume whenever the
-	 * system wakes up in order for USB-PERSIST port handover to work
-	 * properly.
-	 */
-	if (udev->state == USB_STATE_SUSPENDED) {
-		if (udev->parent || udev->speed != USB_SPEED_HIGH)
-			udev->skip_sys_resume = 1;
-		return 0;
-	}
-
-	udev->skip_sys_resume = 0;
-	return usb_external_suspend_device(udev, msg);
+	do_unbind_rebind(udev, DO_UNBIND);
+	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
+	return usb_suspend_both(udev, msg);
 }
 
+/* The device lock is held by the PM core */
 int usb_resume(struct device *dev, pm_message_t msg)
 {
-	struct usb_device	*udev;
+	struct usb_device	*udev = to_usb_device(dev);
 	int			status;
 
-	udev = to_usb_device(dev);
+	/* For PM complete calls, all we do is rebind interfaces */
+	if (msg.event == PM_EVENT_ON) {
+		if (udev->state != USB_STATE_NOTATTACHED)
+			do_unbind_rebind(udev, DO_REBIND);
+		status = 0;
 
-	/* If udev->skip_sys_resume is set then udev was already suspended
-	 * when the system sleep started, so we don't want to resume it
-	 * during this system wakeup.
+	/* For all other calls, take the device back to full power and
+	 * tell the PM core in case it was autosuspended previously.
 	 */
-	if (udev->skip_sys_resume)
-		return 0;
-	status = usb_external_resume_device(udev, msg);
+	} else {
+		status = usb_resume_both(udev, msg);
+		if (status == 0) {
+			pm_runtime_disable(dev);
+			pm_runtime_set_active(dev);
+			pm_runtime_enable(dev);
+			udev->last_busy = jiffies;
+		}
+	}
 
 	/* Avoid PM error messages for devices disconnected while suspended
 	 * as we'll display regular disconnect messages just a bit later.
 	 */
 	if (status == -ENODEV)
-		return 0;
+		status = 0;
 	return status;
 }
 
@@ -1560,54 +1353,6 @@ int usb_disable_autosuspend(struct usb_device *udev)
 }
 EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
 
-/* Internal routine to adjust a device's usage counter and change
- * its autosuspend state.
- */
-static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
-{
-	int	status = 0;
-
-	usb_pm_lock(udev);
-	udev->pm_usage_cnt += inc_usage_cnt;
-	WARN_ON(udev->pm_usage_cnt < 0);
-	if (inc_usage_cnt)
-		udev->last_busy = jiffies;
-	if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
-		if (udev->state == USB_STATE_SUSPENDED)
-			status = usb_resume_both(udev, PMSG_AUTO_RESUME);
-		if (status != 0)
-			udev->pm_usage_cnt -= inc_usage_cnt;
-		else if (inc_usage_cnt)
-			udev->last_busy = jiffies;
-	} else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
-		status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
-	}
-	usb_pm_unlock(udev);
-	return status;
-}
-
-/* usb_autosuspend_work - callback routine to autosuspend a USB device */
-void usb_autosuspend_work(struct work_struct *work)
-{
-	struct usb_device *udev =
-		container_of(work, struct usb_device, autosuspend.work);
-
-	usb_autopm_do_device(udev, 0);
-}
-
-/* usb_autoresume_work - callback routine to autoresume a USB device */
-void usb_autoresume_work(struct work_struct *work)
-{
-	struct usb_device *udev =
-		container_of(work, struct usb_device, autoresume);
-
-	/* Wake it up, let the drivers do their thing, and then put it
-	 * back to sleep.
-	 */
-	if (usb_autopm_do_device(udev, 1) == 0)
-		usb_autopm_do_device(udev, -1);
-}
-
 /**
  * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
  * @udev: the usb_device to autosuspend
@@ -1616,12 +1361,9 @@ void usb_autoresume_work(struct work_struct *work)
  * @udev and wants to allow it to autosuspend.  Examples would be when
  * @udev's device file in usbfs is closed or after a configuration change.
  *
- * @udev's usage counter is decremented.  If it or any of the usage counters
- * for an active interface is greater than 0, no autosuspend request will be
- * queued.  (If an interface driver does not support autosuspend then its
- * usage counter is permanently positive.)  Furthermore, if an interface
- * driver requires remote-wakeup capability during autosuspend but remote
- * wakeup is disabled, the autosuspend will fail.
+ * @udev's usage counter is decremented; if it drops to 0 and all the
+ * interfaces are inactive then a delayed autosuspend will be attempted.
+ * The attempt may fail (see autosuspend_check()).
  *
  * The caller must hold @udev's device lock.
  *
@@ -1631,9 +1373,11 @@ void usb_autosuspend_device(struct usb_device *udev)
 {
 	int	status;
 
-	status = usb_autopm_do_device(udev, -1);
-	dev_vdbg(&udev->dev, "%s: cnt %d\n",
-			__func__, udev->pm_usage_cnt);
+	udev->last_busy = jiffies;
+	status = pm_runtime_put_sync(&udev->dev);
+	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&udev->dev.power.usage_count),
+			status);
 }
 
 /**
@@ -1643,9 +1387,9 @@ void usb_autosuspend_device(struct usb_device *udev)
  * This routine should be called when a core subsystem thinks @udev may
  * be ready to autosuspend.
  *
- * @udev's usage counter left unchanged.  If it or any of the usage counters
- * for an active interface is greater than 0, or autosuspend is not allowed
- * for any other reason, no autosuspend request will be queued.
+ * @udev's usage counter left unchanged.  If it is 0 and all the interfaces
+ * are inactive then an autosuspend will be attempted.  The attempt may
+ * fail or be delayed.
  *
  * The caller must hold @udev's device lock.
  *
@@ -1653,9 +1397,12 @@ void usb_autosuspend_device(struct usb_device *udev)
  */
 void usb_try_autosuspend_device(struct usb_device *udev)
 {
-	usb_autopm_do_device(udev, 0);
-	dev_vdbg(&udev->dev, "%s: cnt %d\n",
-			__func__, udev->pm_usage_cnt);
+	int	status;
+
+	status = pm_runtime_idle(&udev->dev);
+	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&udev->dev.power.usage_count),
+			status);
 }
 
 /**
@@ -1664,9 +1411,9 @@ void usb_try_autosuspend_device(struct usb_device *udev)
  *
  * This routine should be called when a core subsystem wants to use @udev
  * and needs to guarantee that it is not suspended.  No autosuspend will
- * occur until usb_autosuspend_device is called.  (Note that this will not
- * prevent suspend events originating in the PM core.)  Examples would be
- * when @udev's device file in usbfs is opened or when a remote-wakeup
+ * occur until usb_autosuspend_device() is called.  (Note that this will
+ * not prevent suspend events originating in the PM core.)  Examples would
+ * be when @udev's device file in usbfs is opened or when a remote-wakeup
  * request is received.
  *
  * @udev's usage counter is incremented to prevent subsequent autosuspends.
@@ -1680,42 +1427,14 @@ int usb_autoresume_device(struct usb_device *udev)
 {
 	int	status;
 
-	status = usb_autopm_do_device(udev, 1);
-	dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
-			__func__, status, udev->pm_usage_cnt);
-	return status;
-}
-
-/* Internal routine to adjust an interface's usage counter and change
- * its device's autosuspend state.
- */
-static int usb_autopm_do_interface(struct usb_interface *intf,
-		int inc_usage_cnt)
-{
-	struct usb_device	*udev = interface_to_usbdev(intf);
-	int			status = 0;
-
-	usb_pm_lock(udev);
-	if (intf->condition == USB_INTERFACE_UNBOUND)
-		status = -ENODEV;
-	else {
-		atomic_add(inc_usage_cnt, &intf->pm_usage_cnt);
-		udev->last_busy = jiffies;
-		if (inc_usage_cnt >= 0 &&
-				atomic_read(&intf->pm_usage_cnt) > 0) {
-			if (udev->state == USB_STATE_SUSPENDED)
-				status = usb_resume_both(udev,
-						PMSG_AUTO_RESUME);
-			if (status != 0)
-				atomic_sub(inc_usage_cnt, &intf->pm_usage_cnt);
-			else
-				udev->last_busy = jiffies;
-		} else if (inc_usage_cnt <= 0 &&
-				atomic_read(&intf->pm_usage_cnt) <= 0) {
-			status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
-		}
-	}
-	usb_pm_unlock(udev);
+	status = pm_runtime_get_sync(&udev->dev);
+	if (status < 0)
+		pm_runtime_put_sync(&udev->dev);
+	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&udev->dev.power.usage_count),
+			status);
+	if (status > 0)
+		status = 0;
 	return status;
 }
 
@@ -1729,34 +1448,25 @@ static int usb_autopm_do_interface(struct usb_interface *intf,
  * closed.
  *
  * The routine decrements @intf's usage counter.  When the counter reaches
- * 0, a delayed autosuspend request for @intf's device is queued.  When
- * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
- * the other usage counters for the sibling interfaces and @intf's
- * usb_device, the device and all its interfaces will be autosuspended.
- *
- * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
- * core will not change its value other than the increment and decrement
- * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
- * may use this simple counter-oriented discipline or may set the value
- * any way it likes.
+ * 0, a delayed autosuspend request for @intf's device is attempted.  The
+ * attempt may fail (see autosuspend_check()).
  *
  * If the driver has set @intf->needs_remote_wakeup then autosuspend will
  * take place only if the device's remote-wakeup facility is enabled.
  *
- * Suspend method calls queued by this routine can arrive at any time
- * while @intf is resumed and its usage counter is equal to 0.  They are
- * not protected by the usb_device's lock but only by its pm_mutex.
- * Drivers must provide their own synchronization.
- *
  * This routine can run only in process context.
  */
 void usb_autopm_put_interface(struct usb_interface *intf)
 {
-	int	status;
+	struct usb_device	*udev = interface_to_usbdev(intf);
+	int			status;
 
-	status = usb_autopm_do_interface(intf, -1);
-	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
-			__func__, status, atomic_read(&intf->pm_usage_cnt));
+	udev->last_busy = jiffies;
+	atomic_dec(&intf->pm_usage_cnt);
+	status = pm_runtime_put_sync(&intf->dev);
+	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			status);
 }
 EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
 
@@ -1764,11 +1474,11 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
  * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
  * @intf: the usb_interface whose counter should be decremented
  *
- * This routine does essentially the same thing as
- * usb_autopm_put_interface(): it decrements @intf's usage counter and
- * queues a delayed autosuspend request if the counter is <= 0.  The
- * difference is that it does not acquire the device's pm_mutex;
- * callers must handle all synchronization issues themselves.
+ * This routine does much the same thing as usb_autopm_put_interface():
+ * It decrements @intf's usage counter and schedules a delayed
+ * autosuspend request if the counter is <= 0.  The difference is that it
+ * does not perform any synchronization; callers should hold a private
+ * lock and handle all synchronization issues themselves.
  *
  * Typically a driver would call this routine during an URB's completion
  * handler, if no more URBs were pending.
@@ -1778,28 +1488,58 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
 void usb_autopm_put_interface_async(struct usb_interface *intf)
 {
 	struct usb_device	*udev = interface_to_usbdev(intf);
+	unsigned long		last_busy;
 	int			status = 0;
 
-	if (intf->condition == USB_INTERFACE_UNBOUND) {
-		status = -ENODEV;
-	} else {
-		udev->last_busy = jiffies;
-		atomic_dec(&intf->pm_usage_cnt);
-		if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
-			status = -EPERM;
-		else if (atomic_read(&intf->pm_usage_cnt) <= 0 &&
-				!timer_pending(&udev->autosuspend.timer)) {
-			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
+	last_busy = udev->last_busy;
+	udev->last_busy = jiffies;
+	atomic_dec(&intf->pm_usage_cnt);
+	pm_runtime_put_noidle(&intf->dev);
+
+	if (!udev->autosuspend_disabled) {
+		/* Optimization: Don't schedule a delayed autosuspend if
+		 * the timer is already running and the expiration time
+		 * wouldn't change.
+		 *
+		 * We have to use the interface's timer.  Attempts to
+		 * schedule a suspend for the device would fail because
+		 * the interface is still active.
+		 */
+		if (intf->dev.power.timer_expires == 0 ||
+				round_jiffies_up(last_busy) !=
+				round_jiffies_up(jiffies)) {
+			status = pm_schedule_suspend(&intf->dev,
+					jiffies_to_msecs(
 					round_jiffies_up_relative(
-						udev->autosuspend_delay));
+						udev->autosuspend_delay)));
 		}
 	}
-	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
-			__func__, status, atomic_read(&intf->pm_usage_cnt));
+	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			status);
 }
 EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
 
 /**
+ * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
+ * @intf: the usb_interface whose counter should be decremented
+ *
+ * This routine decrements @intf's usage counter but does not carry out an
+ * autosuspend.
+ *
+ * This routine can run in atomic context.
+ */
+void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
+{
+	struct usb_device	*udev = interface_to_usbdev(intf);
+
+	udev->last_busy = jiffies;
+	atomic_dec(&intf->pm_usage_cnt);
+	pm_runtime_put_noidle(&intf->dev);
+}
+EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
+
+/**
  * usb_autopm_get_interface - increment a USB interface's PM-usage counter
  * @intf: the usb_interface whose counter should be incremented
  *
@@ -1811,25 +1551,8 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
  * or @intf is unbound.  A typical example would be a character-device
  * driver when its device file is opened.
  *
- *
- * The routine increments @intf's usage counter.  (However if the
- * autoresume fails then the counter is re-decremented.)  So long as the
- * counter is greater than 0, autosuspend will not be allowed for @intf
- * or its usb_device.  When the driver is finished using @intf it should
- * call usb_autopm_put_interface() to decrement the usage counter and
- * queue a delayed autosuspend request (if the counter is <= 0).
- *
- *
- * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
- * core will not change its value other than the increment and decrement
- * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
- * may use this simple counter-oriented discipline or may set the value
- * any way it likes.
- *
- * Resume method calls generated by this routine can arrive at any time
- * while @intf is suspended.  They are not protected by the usb_device's
- * lock but only by its pm_mutex.  Drivers must provide their own
- * synchronization.
+ * @intf's usage counter is incremented to prevent subsequent autosuspends.
+ * However if the autoresume fails then the counter is re-decremented.
  *
  * This routine can run only in process context.
  */
@@ -1837,9 +1560,16 @@ int usb_autopm_get_interface(struct usb_interface *intf)
 {
 	int	status;
 
-	status = usb_autopm_do_interface(intf, 1);
-	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
-			__func__, status, atomic_read(&intf->pm_usage_cnt));
+	status = pm_runtime_get_sync(&intf->dev);
+	if (status < 0)
+		pm_runtime_put_sync(&intf->dev);
+	else
+		atomic_inc(&intf->pm_usage_cnt);
+	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			status);
+	if (status > 0)
+		status = 0;
 	return status;
 }
 EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
@@ -1849,41 +1579,201 @@ EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
  * @intf: the usb_interface whose counter should be incremented
  *
  * This routine does much the same thing as
- * usb_autopm_get_interface(): it increments @intf's usage counter and
- * queues an autoresume request if the result is > 0.  The differences
- * are that it does not acquire the device's pm_mutex (callers must
- * handle all synchronization issues themselves), and it does not
- * autoresume the device directly (it only queues a request).  After a
- * successful call, the device will generally not yet be resumed.
+ * usb_autopm_get_interface(): It increments @intf's usage counter and
+ * queues an autoresume request if the device is suspended.  The
+ * differences are that it does not perform any synchronization (callers
+ * should hold a private lock and handle all synchronization issues
+ * themselves), and it does not autoresume the device directly (it only
+ * queues a request).  After a successful call, the device may not yet be
+ * resumed.
  *
  * This routine can run in atomic context.
  */
 int usb_autopm_get_interface_async(struct usb_interface *intf)
 {
-	struct usb_device	*udev = interface_to_usbdev(intf);
-	int			status = 0;
+	int		status = 0;
+	enum rpm_status	s;
 
-	if (intf->condition == USB_INTERFACE_UNBOUND)
-		status = -ENODEV;
-	else {
+	/* Don't request a resume unless the interface is already suspending
+	 * or suspended.  Doing so would force a running suspend timer to be
+	 * cancelled.
+	 */
+	pm_runtime_get_noresume(&intf->dev);
+	s = ACCESS_ONCE(intf->dev.power.runtime_status);
+	if (s == RPM_SUSPENDING || s == RPM_SUSPENDED)
+		status = pm_request_resume(&intf->dev);
+
+	if (status < 0 && status != -EINPROGRESS)
+		pm_runtime_put_noidle(&intf->dev);
+	else
 		atomic_inc(&intf->pm_usage_cnt);
-		if (atomic_read(&intf->pm_usage_cnt) > 0 &&
-				udev->state == USB_STATE_SUSPENDED)
-			queue_work(ksuspend_usb_wq, &udev->autoresume);
-	}
-	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
-			__func__, status, atomic_read(&intf->pm_usage_cnt));
+	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
+			__func__, atomic_read(&intf->dev.power.usage_count),
+			status);
+	if (status > 0)
+		status = 0;
 	return status;
 }
 EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
 
-#else
+/**
+ * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
+ * @intf: the usb_interface whose counter should be incremented
+ *
+ * This routine increments @intf's usage counter but does not carry out an
+ * autoresume.
+ *
+ * This routine can run in atomic context.
+ */
+void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
+{
+	struct usb_device	*udev = interface_to_usbdev(intf);
+
+	udev->last_busy = jiffies;
+	atomic_inc(&intf->pm_usage_cnt);
+	pm_runtime_get_noresume(&intf->dev);
+}
+EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
+
+/* Internal routine to check whether we may autosuspend a device. */
+static int autosuspend_check(struct usb_device *udev)
+{
+	int			i;
+	struct usb_interface	*intf;
+	unsigned long		suspend_time, j;
+
+	/* Fail if autosuspend is disabled, or any interfaces are in use, or
+	 * any interface drivers require remote wakeup but it isn't available.
+	 */
+	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
+	if (udev->actconfig) {
+		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
+			intf = udev->actconfig->interface[i];
+
+			/* We don't need to check interfaces that are
+			 * disabled for runtime PM.  Either they are unbound
+			 * or else their drivers don't support autosuspend
+			 * and so they are permanently active.
+			 */
+			if (intf->dev.power.disable_depth)
+				continue;
+			if (atomic_read(&intf->dev.power.usage_count) > 0)
+				return -EBUSY;
+			if (intf->needs_remote_wakeup &&
+					!udev->do_remote_wakeup) {
+				dev_dbg(&udev->dev, "remote wakeup needed "
+						"for autosuspend\n");
+				return -EOPNOTSUPP;
+			}
+
+			/* Don't allow autosuspend if the device will need
+			 * a reset-resume and any of its interface drivers
+			 * doesn't include support or needs remote wakeup.
+			 */
+			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
+				struct usb_driver *driver;
+
+				driver = to_usb_driver(intf->dev.driver);
+				if (!driver->reset_resume ||
+						intf->needs_remote_wakeup)
+					return -EOPNOTSUPP;
+			}
+		}
+	}
+
+	/* If everything is okay but the device hasn't been idle for long
+	 * enough, queue a delayed autosuspend request.
+	 */
+	j = ACCESS_ONCE(jiffies);
+	suspend_time = udev->last_busy + udev->autosuspend_delay;
+	if (time_before(j, suspend_time)) {
+		pm_schedule_suspend(&udev->dev, jiffies_to_msecs(
+				round_jiffies_up_relative(suspend_time - j)));
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static int usb_runtime_suspend(struct device *dev)
+{
+	int	status = 0;
 
-void usb_autosuspend_work(struct work_struct *work)
-{}
+	/* A USB device can be suspended if it passes the various autosuspend
+	 * checks.  Runtime suspend for a USB device means suspending all the
+	 * interfaces and then the device itself.
+	 */
+	if (is_usb_device(dev)) {
+		struct usb_device	*udev = to_usb_device(dev);
+
+		if (autosuspend_check(udev) != 0)
+			return -EAGAIN;
+
+		status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
+
+		/* If an interface fails the suspend, adjust the last_busy
+		 * time so that we don't get another suspend attempt right
+		 * away.
+		 */
+		if (status) {
+			udev->last_busy = jiffies +
+					(udev->autosuspend_delay == 0 ?
+						HZ/2 : 0);
+		}
+
+		/* Prevent the parent from suspending immediately after */
+		else if (udev->parent) {
+			udev->parent->last_busy = jiffies;
+		}
+	}
+
+	/* Runtime suspend for a USB interface doesn't mean anything. */
+	return status;
+}
+
+static int usb_runtime_resume(struct device *dev)
+{
+	/* Runtime resume for a USB device means resuming both the device
+	 * and all its interfaces.
+	 */
+	if (is_usb_device(dev)) {
+		struct usb_device	*udev = to_usb_device(dev);
+		int			status;
+
+		status = usb_resume_both(udev, PMSG_AUTO_RESUME);
+		udev->last_busy = jiffies;
+		return status;
+	}
+
+	/* Runtime resume for a USB interface doesn't mean anything. */
+	return 0;
+}
+
+static int usb_runtime_idle(struct device *dev)
+{
+	/* An idle USB device can be suspended if it passes the various
+	 * autosuspend checks.  An idle interface can be suspended at
+	 * any time.
+	 */
+	if (is_usb_device(dev)) {
+		struct usb_device	*udev = to_usb_device(dev);
+
+		if (autosuspend_check(udev) != 0)
+			return 0;
+	}
+
+	pm_runtime_suspend(dev);
+	return 0;
+}
+
+static struct dev_pm_ops usb_bus_pm_ops = {
+	.runtime_suspend =	usb_runtime_suspend,
+	.runtime_resume =	usb_runtime_resume,
+	.runtime_idle =		usb_runtime_idle,
+};
+
+#else
 
-void usb_autoresume_work(struct work_struct *work)
-{}
+#define usb_bus_pm_ops	(*(struct dev_pm_ops *) NULL)
 
 #endif /* CONFIG_USB_SUSPEND */
 
@@ -1891,4 +1781,5 @@ struct bus_type usb_bus_type = {
 	.name =		"usb",
 	.match =	usb_device_match,
 	.uevent =	usb_uevent,
+	.pm =		&usb_bus_pm_ops,
 };