2 * drivers/base/power/runtime.c - Helper functions for device runtime PM
4 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
7 * This file is released under the GPLv2.
10 #include <linux/sched.h>
11 #include <linux/export.h>
12 #include <linux/pm_runtime.h>
13 #include <trace/events/rpm.h>
16 static int rpm_resume(struct device *dev, int rpmflags);
17 static int rpm_suspend(struct device *dev, int rpmflags);
20 * update_pm_runtime_accounting - Update the time accounting of power states
21 * @dev: Device to update the accounting for
23 * In order to be able to have time accounting of the various power states
24 * (as used by programs such as PowerTOP to show the effectiveness of runtime
25 * PM), we need to track the time spent in each state.
26 * update_pm_runtime_accounting must be called each time before the
27 * runtime_status field is updated, to account the time in the old state
30 void update_pm_runtime_accounting(struct device *dev)
32 unsigned long now = jiffies;
35 delta = now - dev->power.accounting_timestamp;
37 dev->power.accounting_timestamp = now;
39 if (dev->power.disable_depth > 0)
42 if (dev->power.runtime_status == RPM_SUSPENDED)
43 dev->power.suspended_jiffies += delta;
45 dev->power.active_jiffies += delta;
48 static void __update_runtime_status(struct device *dev, enum rpm_status status)
50 update_pm_runtime_accounting(dev);
51 dev->power.runtime_status = status;
55 * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
56 * @dev: Device to handle.
58 static void pm_runtime_deactivate_timer(struct device *dev)
60 if (dev->power.timer_expires > 0) {
61 del_timer(&dev->power.suspend_timer);
62 dev->power.timer_expires = 0;
67 * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
68 * @dev: Device to handle.
70 static void pm_runtime_cancel_pending(struct device *dev)
72 pm_runtime_deactivate_timer(dev);
74 * In case there's a request pending, make sure its work function will
75 * return without doing anything.
77 dev->power.request = RPM_REQ_NONE;
81 * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
82 * @dev: Device to handle.
84 * Compute the autosuspend-delay expiration time based on the device's
85 * power.last_busy time. If the delay has already expired or is disabled
86 * (negative) or the power.use_autosuspend flag isn't set, return 0.
87 * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
89 * This function may be called either with or without dev->power.lock held.
90 * Either way it can be racy, since power.last_busy may be updated at any time.
92 unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
94 int autosuspend_delay;
96 unsigned long last_busy;
97 unsigned long expires = 0;
99 if (!dev->power.use_autosuspend)
102 autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
103 if (autosuspend_delay < 0)
106 last_busy = ACCESS_ONCE(dev->power.last_busy);
107 elapsed = jiffies - last_busy;
109 goto out; /* jiffies has wrapped around. */
112 * If the autosuspend_delay is >= 1 second, align the timer by rounding
113 * up to the nearest second.
115 expires = last_busy + msecs_to_jiffies(autosuspend_delay);
116 if (autosuspend_delay >= 1000)
117 expires = round_jiffies(expires);
119 if (elapsed >= expires - last_busy)
120 expires = 0; /* Already expired. */
125 EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
128 * rpm_check_suspend_allowed - Test whether a device may be suspended.
129 * @dev: Device to test.
131 static int rpm_check_suspend_allowed(struct device *dev)
135 if (dev->power.runtime_error)
137 else if (dev->power.disable_depth > 0)
139 else if (atomic_read(&dev->power.usage_count) > 0)
141 else if (!pm_children_suspended(dev))
144 /* Pending resume requests take precedence over suspends. */
145 else if ((dev->power.deferred_resume
146 && dev->power.runtime_status == RPM_SUSPENDING)
147 || (dev->power.request_pending
148 && dev->power.request == RPM_REQ_RESUME))
150 else if (dev->power.runtime_status == RPM_SUSPENDED)
157 * __rpm_callback - Run a given runtime PM callback for a given device.
158 * @cb: Runtime PM callback to run.
159 * @dev: Device to run the callback for.
161 static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
162 __releases(&dev->power.lock) __acquires(&dev->power.lock)
166 if (dev->power.irq_safe)
167 spin_unlock(&dev->power.lock);
169 spin_unlock_irq(&dev->power.lock);
173 if (dev->power.irq_safe)
174 spin_lock(&dev->power.lock);
176 spin_lock_irq(&dev->power.lock);
182 * rpm_idle - Notify device bus type if the device can be suspended.
183 * @dev: Device to notify the bus type about.
184 * @rpmflags: Flag bits.
186 * Check if the device's runtime PM status allows it to be suspended. If
187 * another idle notification has been started earlier, return immediately. If
188 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
189 * run the ->runtime_idle() callback directly.
191 * This function must be called under dev->power.lock with interrupts disabled.
193 static int rpm_idle(struct device *dev, int rpmflags)
195 int (*callback)(struct device *);
198 trace_rpm_idle(dev, rpmflags);
199 retval = rpm_check_suspend_allowed(dev);
201 ; /* Conditions are wrong. */
203 /* Idle notifications are allowed only in the RPM_ACTIVE state. */
204 else if (dev->power.runtime_status != RPM_ACTIVE)
208 * Any pending request other than an idle notification takes
209 * precedence over us, except that the timer may be running.
211 else if (dev->power.request_pending &&
212 dev->power.request > RPM_REQ_IDLE)
215 /* Act as though RPM_NOWAIT is always set. */
216 else if (dev->power.idle_notification)
217 retval = -EINPROGRESS;
221 /* Pending requests need to be canceled. */
222 dev->power.request = RPM_REQ_NONE;
224 if (dev->power.no_callbacks) {
225 /* Assume ->runtime_idle() callback would have suspended. */
226 retval = rpm_suspend(dev, rpmflags);
230 /* Carry out an asynchronous or a synchronous idle notification. */
231 if (rpmflags & RPM_ASYNC) {
232 dev->power.request = RPM_REQ_IDLE;
233 if (!dev->power.request_pending) {
234 dev->power.request_pending = true;
235 queue_work(pm_wq, &dev->power.work);
240 dev->power.idle_notification = true;
243 callback = dev->pm_domain->ops.runtime_idle;
244 else if (dev->type && dev->type->pm)
245 callback = dev->type->pm->runtime_idle;
246 else if (dev->class && dev->class->pm)
247 callback = dev->class->pm->runtime_idle;
248 else if (dev->bus && dev->bus->pm)
249 callback = dev->bus->pm->runtime_idle;
253 if (!callback && dev->driver && dev->driver->pm)
254 callback = dev->driver->pm->runtime_idle;
257 __rpm_callback(callback, dev);
259 dev->power.idle_notification = false;
260 wake_up_all(&dev->power.wait_queue);
263 trace_rpm_return_int(dev, _THIS_IP_, retval);
268 * rpm_callback - Run a given runtime PM callback for a given device.
269 * @cb: Runtime PM callback to run.
270 * @dev: Device to run the callback for.
272 static int rpm_callback(int (*cb)(struct device *), struct device *dev)
279 retval = __rpm_callback(cb, dev);
281 dev->power.runtime_error = retval;
282 return retval != -EACCES ? retval : -EIO;
286 * rpm_suspend - Carry out runtime suspend of given device.
287 * @dev: Device to suspend.
288 * @rpmflags: Flag bits.
290 * Check if the device's runtime PM status allows it to be suspended.
291 * Cancel a pending idle notification, autosuspend or suspend. If
292 * another suspend has been started earlier, either return immediately
293 * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
294 * flags. If the RPM_ASYNC flag is set then queue a suspend request;
295 * otherwise run the ->runtime_suspend() callback directly. When
296 * ->runtime_suspend succeeded, if a deferred resume was requested while
297 * the callback was running then carry it out, otherwise send an idle
298 * notification for its parent (if the suspend succeeded and both
299 * ignore_children of parent->power and irq_safe of dev->power are not set).
300 * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
301 * flag is set and the next autosuspend-delay expiration time is in the
302 * future, schedule another autosuspend attempt.
304 * This function must be called under dev->power.lock with interrupts disabled.
306 static int rpm_suspend(struct device *dev, int rpmflags)
307 __releases(&dev->power.lock) __acquires(&dev->power.lock)
309 int (*callback)(struct device *);
310 struct device *parent = NULL;
313 trace_rpm_suspend(dev, rpmflags);
316 retval = rpm_check_suspend_allowed(dev);
319 ; /* Conditions are wrong. */
321 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
322 else if (dev->power.runtime_status == RPM_RESUMING &&
323 !(rpmflags & RPM_ASYNC))
328 /* If the autosuspend_delay time hasn't expired yet, reschedule. */
329 if ((rpmflags & RPM_AUTO)
330 && dev->power.runtime_status != RPM_SUSPENDING) {
331 unsigned long expires = pm_runtime_autosuspend_expiration(dev);
334 /* Pending requests need to be canceled. */
335 dev->power.request = RPM_REQ_NONE;
338 * Optimization: If the timer is already running and is
339 * set to expire at or before the autosuspend delay,
340 * avoid the overhead of resetting it. Just let it
341 * expire; pm_suspend_timer_fn() will take care of the
344 if (!(dev->power.timer_expires && time_before_eq(
345 dev->power.timer_expires, expires))) {
346 dev->power.timer_expires = expires;
347 mod_timer(&dev->power.suspend_timer, expires);
349 dev->power.timer_autosuspends = 1;
354 /* Other scheduled or pending requests need to be canceled. */
355 pm_runtime_cancel_pending(dev);
357 if (dev->power.runtime_status == RPM_SUSPENDING) {
360 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
361 retval = -EINPROGRESS;
365 if (dev->power.irq_safe) {
366 spin_unlock(&dev->power.lock);
370 spin_lock(&dev->power.lock);
374 /* Wait for the other suspend running in parallel with us. */
376 prepare_to_wait(&dev->power.wait_queue, &wait,
377 TASK_UNINTERRUPTIBLE);
378 if (dev->power.runtime_status != RPM_SUSPENDING)
381 spin_unlock_irq(&dev->power.lock);
385 spin_lock_irq(&dev->power.lock);
387 finish_wait(&dev->power.wait_queue, &wait);
391 dev->power.deferred_resume = false;
392 if (dev->power.no_callbacks)
393 goto no_callback; /* Assume success. */
395 /* Carry out an asynchronous or a synchronous suspend. */
396 if (rpmflags & RPM_ASYNC) {
397 dev->power.request = (rpmflags & RPM_AUTO) ?
398 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
399 if (!dev->power.request_pending) {
400 dev->power.request_pending = true;
401 queue_work(pm_wq, &dev->power.work);
406 if (__dev_pm_qos_read_value(dev) < 0) {
407 /* Negative PM QoS constraint means "never suspend". */
412 __update_runtime_status(dev, RPM_SUSPENDING);
415 callback = dev->pm_domain->ops.runtime_suspend;
416 else if (dev->type && dev->type->pm)
417 callback = dev->type->pm->runtime_suspend;
418 else if (dev->class && dev->class->pm)
419 callback = dev->class->pm->runtime_suspend;
420 else if (dev->bus && dev->bus->pm)
421 callback = dev->bus->pm->runtime_suspend;
425 if (!callback && dev->driver && dev->driver->pm)
426 callback = dev->driver->pm->runtime_suspend;
428 retval = rpm_callback(callback, dev);
433 __update_runtime_status(dev, RPM_SUSPENDED);
434 pm_runtime_deactivate_timer(dev);
437 parent = dev->parent;
438 atomic_add_unless(&parent->power.child_count, -1, 0);
440 wake_up_all(&dev->power.wait_queue);
442 if (dev->power.deferred_resume) {
448 /* Maybe the parent is now able to suspend. */
449 if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
450 spin_unlock(&dev->power.lock);
452 spin_lock(&parent->power.lock);
453 rpm_idle(parent, RPM_ASYNC);
454 spin_unlock(&parent->power.lock);
456 spin_lock(&dev->power.lock);
460 trace_rpm_return_int(dev, _THIS_IP_, retval);
465 __update_runtime_status(dev, RPM_ACTIVE);
466 dev->power.deferred_resume = false;
467 wake_up_all(&dev->power.wait_queue);
469 if (retval == -EAGAIN || retval == -EBUSY) {
470 dev->power.runtime_error = 0;
473 * If the callback routine failed an autosuspend, and
474 * if the last_busy time has been updated so that there
475 * is a new autosuspend expiration time, automatically
476 * reschedule another autosuspend.
478 if ((rpmflags & RPM_AUTO) &&
479 pm_runtime_autosuspend_expiration(dev) != 0)
482 pm_runtime_cancel_pending(dev);
488 * rpm_resume - Carry out runtime resume of given device.
489 * @dev: Device to resume.
490 * @rpmflags: Flag bits.
492 * Check if the device's runtime PM status allows it to be resumed. Cancel
493 * any scheduled or pending requests. If another resume has been started
494 * earlier, either return immediately or wait for it to finish, depending on the
495 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
496 * parallel with this function, either tell the other process to resume after
497 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
498 * flag is set then queue a resume request; otherwise run the
499 * ->runtime_resume() callback directly. Queue an idle notification for the
500 * device if the resume succeeded.
502 * This function must be called under dev->power.lock with interrupts disabled.
504 static int rpm_resume(struct device *dev, int rpmflags)
505 __releases(&dev->power.lock) __acquires(&dev->power.lock)
507 int (*callback)(struct device *);
508 struct device *parent = NULL;
511 trace_rpm_resume(dev, rpmflags);
514 if (dev->power.runtime_error)
516 else if (dev->power.disable_depth > 0)
522 * Other scheduled or pending requests need to be canceled. Small
523 * optimization: If an autosuspend timer is running, leave it running
524 * rather than cancelling it now only to restart it again in the near
527 dev->power.request = RPM_REQ_NONE;
528 if (!dev->power.timer_autosuspends)
529 pm_runtime_deactivate_timer(dev);
531 if (dev->power.runtime_status == RPM_ACTIVE) {
536 if (dev->power.runtime_status == RPM_RESUMING
537 || dev->power.runtime_status == RPM_SUSPENDING) {
540 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
541 if (dev->power.runtime_status == RPM_SUSPENDING)
542 dev->power.deferred_resume = true;
544 retval = -EINPROGRESS;
548 if (dev->power.irq_safe) {
549 spin_unlock(&dev->power.lock);
553 spin_lock(&dev->power.lock);
557 /* Wait for the operation carried out in parallel with us. */
559 prepare_to_wait(&dev->power.wait_queue, &wait,
560 TASK_UNINTERRUPTIBLE);
561 if (dev->power.runtime_status != RPM_RESUMING
562 && dev->power.runtime_status != RPM_SUSPENDING)
565 spin_unlock_irq(&dev->power.lock);
569 spin_lock_irq(&dev->power.lock);
571 finish_wait(&dev->power.wait_queue, &wait);
576 * See if we can skip waking up the parent. This is safe only if
577 * power.no_callbacks is set, because otherwise we don't know whether
578 * the resume will actually succeed.
580 if (dev->power.no_callbacks && !parent && dev->parent) {
581 spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
582 if (dev->parent->power.disable_depth > 0
583 || dev->parent->power.ignore_children
584 || dev->parent->power.runtime_status == RPM_ACTIVE) {
585 atomic_inc(&dev->parent->power.child_count);
586 spin_unlock(&dev->parent->power.lock);
587 goto no_callback; /* Assume success. */
589 spin_unlock(&dev->parent->power.lock);
592 /* Carry out an asynchronous or a synchronous resume. */
593 if (rpmflags & RPM_ASYNC) {
594 dev->power.request = RPM_REQ_RESUME;
595 if (!dev->power.request_pending) {
596 dev->power.request_pending = true;
597 queue_work(pm_wq, &dev->power.work);
603 if (!parent && dev->parent) {
605 * Increment the parent's usage counter and resume it if
606 * necessary. Not needed if dev is irq-safe; then the
607 * parent is permanently resumed.
609 parent = dev->parent;
610 if (dev->power.irq_safe)
612 spin_unlock(&dev->power.lock);
614 pm_runtime_get_noresume(parent);
616 spin_lock(&parent->power.lock);
618 * We can resume if the parent's runtime PM is disabled or it
619 * is set to ignore children.
621 if (!parent->power.disable_depth
622 && !parent->power.ignore_children) {
623 rpm_resume(parent, 0);
624 if (parent->power.runtime_status != RPM_ACTIVE)
627 spin_unlock(&parent->power.lock);
629 spin_lock(&dev->power.lock);
636 if (dev->power.no_callbacks)
637 goto no_callback; /* Assume success. */
639 __update_runtime_status(dev, RPM_RESUMING);
642 callback = dev->pm_domain->ops.runtime_resume;
643 else if (dev->type && dev->type->pm)
644 callback = dev->type->pm->runtime_resume;
645 else if (dev->class && dev->class->pm)
646 callback = dev->class->pm->runtime_resume;
647 else if (dev->bus && dev->bus->pm)
648 callback = dev->bus->pm->runtime_resume;
652 if (!callback && dev->driver && dev->driver->pm)
653 callback = dev->driver->pm->runtime_resume;
655 retval = rpm_callback(callback, dev);
657 __update_runtime_status(dev, RPM_SUSPENDED);
658 pm_runtime_cancel_pending(dev);
661 __update_runtime_status(dev, RPM_ACTIVE);
663 atomic_inc(&parent->power.child_count);
665 wake_up_all(&dev->power.wait_queue);
668 rpm_idle(dev, RPM_ASYNC);
671 if (parent && !dev->power.irq_safe) {
672 spin_unlock_irq(&dev->power.lock);
674 pm_runtime_put(parent);
676 spin_lock_irq(&dev->power.lock);
679 trace_rpm_return_int(dev, _THIS_IP_, retval);
685 * pm_runtime_work - Universal runtime PM work function.
686 * @work: Work structure used for scheduling the execution of this function.
688 * Use @work to get the device object the work is to be done for, determine what
689 * is to be done and execute the appropriate runtime PM function.
691 static void pm_runtime_work(struct work_struct *work)
693 struct device *dev = container_of(work, struct device, power.work);
694 enum rpm_request req;
696 spin_lock_irq(&dev->power.lock);
698 if (!dev->power.request_pending)
701 req = dev->power.request;
702 dev->power.request = RPM_REQ_NONE;
703 dev->power.request_pending = false;
709 rpm_idle(dev, RPM_NOWAIT);
711 case RPM_REQ_SUSPEND:
712 rpm_suspend(dev, RPM_NOWAIT);
714 case RPM_REQ_AUTOSUSPEND:
715 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
718 rpm_resume(dev, RPM_NOWAIT);
723 spin_unlock_irq(&dev->power.lock);
727 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
728 * @data: Device pointer passed by pm_schedule_suspend().
730 * Check if the time is right and queue a suspend request.
732 static void pm_suspend_timer_fn(unsigned long data)
734 struct device *dev = (struct device *)data;
736 unsigned long expires;
738 spin_lock_irqsave(&dev->power.lock, flags);
740 expires = dev->power.timer_expires;
741 /* If 'expire' is after 'jiffies' we've been called too early. */
742 if (expires > 0 && !time_after(expires, jiffies)) {
743 dev->power.timer_expires = 0;
744 rpm_suspend(dev, dev->power.timer_autosuspends ?
745 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
748 spin_unlock_irqrestore(&dev->power.lock, flags);
752 * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
753 * @dev: Device to suspend.
754 * @delay: Time to wait before submitting a suspend request, in milliseconds.
756 int pm_schedule_suspend(struct device *dev, unsigned int delay)
761 spin_lock_irqsave(&dev->power.lock, flags);
764 retval = rpm_suspend(dev, RPM_ASYNC);
768 retval = rpm_check_suspend_allowed(dev);
772 /* Other scheduled or pending requests need to be canceled. */
773 pm_runtime_cancel_pending(dev);
775 dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
776 dev->power.timer_expires += !dev->power.timer_expires;
777 dev->power.timer_autosuspends = 0;
778 mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
781 spin_unlock_irqrestore(&dev->power.lock, flags);
785 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
788 * __pm_runtime_idle - Entry point for runtime idle operations.
789 * @dev: Device to send idle notification for.
790 * @rpmflags: Flag bits.
792 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
793 * return immediately if it is larger than zero. Then carry out an idle
794 * notification, either synchronous or asynchronous.
796 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
797 * or if pm_runtime_irq_safe() has been called.
799 int __pm_runtime_idle(struct device *dev, int rpmflags)
804 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
806 if (rpmflags & RPM_GET_PUT) {
807 if (!atomic_dec_and_test(&dev->power.usage_count))
811 spin_lock_irqsave(&dev->power.lock, flags);
812 retval = rpm_idle(dev, rpmflags);
813 spin_unlock_irqrestore(&dev->power.lock, flags);
817 EXPORT_SYMBOL_GPL(__pm_runtime_idle);
820 * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
821 * @dev: Device to suspend.
822 * @rpmflags: Flag bits.
824 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
825 * return immediately if it is larger than zero. Then carry out a suspend,
826 * either synchronous or asynchronous.
828 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
829 * or if pm_runtime_irq_safe() has been called.
831 int __pm_runtime_suspend(struct device *dev, int rpmflags)
836 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
838 if (rpmflags & RPM_GET_PUT) {
839 if (!atomic_dec_and_test(&dev->power.usage_count))
843 spin_lock_irqsave(&dev->power.lock, flags);
844 retval = rpm_suspend(dev, rpmflags);
845 spin_unlock_irqrestore(&dev->power.lock, flags);
849 EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
852 * __pm_runtime_resume - Entry point for runtime resume operations.
853 * @dev: Device to resume.
854 * @rpmflags: Flag bits.
856 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
857 * carry out a resume, either synchronous or asynchronous.
859 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
860 * or if pm_runtime_irq_safe() has been called.
862 int __pm_runtime_resume(struct device *dev, int rpmflags)
867 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
869 if (rpmflags & RPM_GET_PUT)
870 atomic_inc(&dev->power.usage_count);
872 spin_lock_irqsave(&dev->power.lock, flags);
873 retval = rpm_resume(dev, rpmflags);
874 spin_unlock_irqrestore(&dev->power.lock, flags);
878 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
881 * __pm_runtime_set_status - Set runtime PM status of a device.
882 * @dev: Device to handle.
883 * @status: New runtime PM status of the device.
885 * If runtime PM of the device is disabled or its power.runtime_error field is
886 * different from zero, the status may be changed either to RPM_ACTIVE, or to
887 * RPM_SUSPENDED, as long as that reflects the actual state of the device.
888 * However, if the device has a parent and the parent is not active, and the
889 * parent's power.ignore_children flag is unset, the device's status cannot be
890 * set to RPM_ACTIVE, so -EBUSY is returned in that case.
892 * If successful, __pm_runtime_set_status() clears the power.runtime_error field
893 * and the device parent's counter of unsuspended children is modified to
894 * reflect the new status. If the new status is RPM_SUSPENDED, an idle
895 * notification request for the parent is submitted.
897 int __pm_runtime_set_status(struct device *dev, unsigned int status)
899 struct device *parent = dev->parent;
901 bool notify_parent = false;
904 if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
907 spin_lock_irqsave(&dev->power.lock, flags);
909 if (!dev->power.runtime_error && !dev->power.disable_depth) {
914 if (dev->power.runtime_status == status)
917 if (status == RPM_SUSPENDED) {
918 /* It always is possible to set the status to 'suspended'. */
920 atomic_add_unless(&parent->power.child_count, -1, 0);
921 notify_parent = !parent->power.ignore_children;
927 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
930 * It is invalid to put an active child under a parent that is
931 * not active, has runtime PM enabled and the
932 * 'power.ignore_children' flag unset.
934 if (!parent->power.disable_depth
935 && !parent->power.ignore_children
936 && parent->power.runtime_status != RPM_ACTIVE)
938 else if (dev->power.runtime_status == RPM_SUSPENDED)
939 atomic_inc(&parent->power.child_count);
941 spin_unlock(&parent->power.lock);
948 __update_runtime_status(dev, status);
949 dev->power.runtime_error = 0;
951 spin_unlock_irqrestore(&dev->power.lock, flags);
954 pm_request_idle(parent);
958 EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
961 * __pm_runtime_barrier - Cancel pending requests and wait for completions.
962 * @dev: Device to handle.
964 * Flush all pending requests for the device from pm_wq and wait for all
965 * runtime PM operations involving the device in progress to complete.
967 * Should be called under dev->power.lock with interrupts disabled.
969 static void __pm_runtime_barrier(struct device *dev)
971 pm_runtime_deactivate_timer(dev);
973 if (dev->power.request_pending) {
974 dev->power.request = RPM_REQ_NONE;
975 spin_unlock_irq(&dev->power.lock);
977 cancel_work_sync(&dev->power.work);
979 spin_lock_irq(&dev->power.lock);
980 dev->power.request_pending = false;
983 if (dev->power.runtime_status == RPM_SUSPENDING
984 || dev->power.runtime_status == RPM_RESUMING
985 || dev->power.idle_notification) {
988 /* Suspend, wake-up or idle notification in progress. */
990 prepare_to_wait(&dev->power.wait_queue, &wait,
991 TASK_UNINTERRUPTIBLE);
992 if (dev->power.runtime_status != RPM_SUSPENDING
993 && dev->power.runtime_status != RPM_RESUMING
994 && !dev->power.idle_notification)
996 spin_unlock_irq(&dev->power.lock);
1000 spin_lock_irq(&dev->power.lock);
1002 finish_wait(&dev->power.wait_queue, &wait);
1007 * pm_runtime_barrier - Flush pending requests and wait for completions.
1008 * @dev: Device to handle.
1010 * Prevent the device from being suspended by incrementing its usage counter and
1011 * if there's a pending resume request for the device, wake the device up.
1012 * Next, make sure that all pending requests for the device have been flushed
1013 * from pm_wq and wait for all runtime PM operations involving the device in
1014 * progress to complete.
1017 * 1, if there was a resume request pending and the device had to be woken up,
1020 int pm_runtime_barrier(struct device *dev)
1024 pm_runtime_get_noresume(dev);
1025 spin_lock_irq(&dev->power.lock);
1027 if (dev->power.request_pending
1028 && dev->power.request == RPM_REQ_RESUME) {
1033 __pm_runtime_barrier(dev);
1035 spin_unlock_irq(&dev->power.lock);
1036 pm_runtime_put_noidle(dev);
1040 EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1043 * __pm_runtime_disable - Disable runtime PM of a device.
1044 * @dev: Device to handle.
1045 * @check_resume: If set, check if there's a resume request for the device.
1047 * Increment power.disable_depth for the device and if was zero previously,
1048 * cancel all pending runtime PM requests for the device and wait for all
1049 * operations in progress to complete. The device can be either active or
1050 * suspended after its runtime PM has been disabled.
1052 * If @check_resume is set and there's a resume request pending when
1053 * __pm_runtime_disable() is called and power.disable_depth is zero, the
1054 * function will wake up the device before disabling its runtime PM.
1056 void __pm_runtime_disable(struct device *dev, bool check_resume)
1058 spin_lock_irq(&dev->power.lock);
1060 if (dev->power.disable_depth > 0) {
1061 dev->power.disable_depth++;
1066 * Wake up the device if there's a resume request pending, because that
1067 * means there probably is some I/O to process and disabling runtime PM
1068 * shouldn't prevent the device from processing the I/O.
1070 if (check_resume && dev->power.request_pending
1071 && dev->power.request == RPM_REQ_RESUME) {
1073 * Prevent suspends and idle notifications from being carried
1074 * out after we have woken up the device.
1076 pm_runtime_get_noresume(dev);
1080 pm_runtime_put_noidle(dev);
1083 if (!dev->power.disable_depth++)
1084 __pm_runtime_barrier(dev);
1087 spin_unlock_irq(&dev->power.lock);
1089 EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1092 * pm_runtime_enable - Enable runtime PM of a device.
1093 * @dev: Device to handle.
1095 void pm_runtime_enable(struct device *dev)
1097 unsigned long flags;
1099 spin_lock_irqsave(&dev->power.lock, flags);
1101 if (dev->power.disable_depth > 0)
1102 dev->power.disable_depth--;
1104 dev_warn(dev, "Unbalanced %s!\n", __func__);
1106 spin_unlock_irqrestore(&dev->power.lock, flags);
1108 EXPORT_SYMBOL_GPL(pm_runtime_enable);
1111 * pm_runtime_forbid - Block runtime PM of a device.
1112 * @dev: Device to handle.
1114 * Increase the device's usage count and clear its power.runtime_auto flag,
1115 * so that it cannot be suspended at run time until pm_runtime_allow() is called
1118 void pm_runtime_forbid(struct device *dev)
1120 spin_lock_irq(&dev->power.lock);
1121 if (!dev->power.runtime_auto)
1124 dev->power.runtime_auto = false;
1125 atomic_inc(&dev->power.usage_count);
1129 spin_unlock_irq(&dev->power.lock);
1131 EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1134 * pm_runtime_allow - Unblock runtime PM of a device.
1135 * @dev: Device to handle.
1137 * Decrease the device's usage count and set its power.runtime_auto flag.
1139 void pm_runtime_allow(struct device *dev)
1141 spin_lock_irq(&dev->power.lock);
1142 if (dev->power.runtime_auto)
1145 dev->power.runtime_auto = true;
1146 if (atomic_dec_and_test(&dev->power.usage_count))
1147 rpm_idle(dev, RPM_AUTO);
1150 spin_unlock_irq(&dev->power.lock);
1152 EXPORT_SYMBOL_GPL(pm_runtime_allow);
1155 * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1156 * @dev: Device to handle.
1158 * Set the power.no_callbacks flag, which tells the PM core that this
1159 * device is power-managed through its parent and has no runtime PM
1160 * callbacks of its own. The runtime sysfs attributes will be removed.
1162 void pm_runtime_no_callbacks(struct device *dev)
1164 spin_lock_irq(&dev->power.lock);
1165 dev->power.no_callbacks = 1;
1166 spin_unlock_irq(&dev->power.lock);
1167 if (device_is_registered(dev))
1168 rpm_sysfs_remove(dev);
1170 EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1173 * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1174 * @dev: Device to handle
1176 * Set the power.irq_safe flag, which tells the PM core that the
1177 * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1178 * always be invoked with the spinlock held and interrupts disabled. It also
1179 * causes the parent's usage counter to be permanently incremented, preventing
1180 * the parent from runtime suspending -- otherwise an irq-safe child might have
1181 * to wait for a non-irq-safe parent.
1183 void pm_runtime_irq_safe(struct device *dev)
1186 pm_runtime_get_sync(dev->parent);
1187 spin_lock_irq(&dev->power.lock);
1188 dev->power.irq_safe = 1;
1189 spin_unlock_irq(&dev->power.lock);
1191 EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1194 * update_autosuspend - Handle a change to a device's autosuspend settings.
1195 * @dev: Device to handle.
1196 * @old_delay: The former autosuspend_delay value.
1197 * @old_use: The former use_autosuspend value.
1199 * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1200 * set; otherwise allow it. Send an idle notification if suspends are allowed.
1202 * This function must be called under dev->power.lock with interrupts disabled.
1204 static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1206 int delay = dev->power.autosuspend_delay;
1208 /* Should runtime suspend be prevented now? */
1209 if (dev->power.use_autosuspend && delay < 0) {
1211 /* If it used to be allowed then prevent it. */
1212 if (!old_use || old_delay >= 0) {
1213 atomic_inc(&dev->power.usage_count);
1218 /* Runtime suspend should be allowed now. */
1221 /* If it used to be prevented then allow it. */
1222 if (old_use && old_delay < 0)
1223 atomic_dec(&dev->power.usage_count);
1225 /* Maybe we can autosuspend now. */
1226 rpm_idle(dev, RPM_AUTO);
1231 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1232 * @dev: Device to handle.
1233 * @delay: Value of the new delay in milliseconds.
1235 * Set the device's power.autosuspend_delay value. If it changes to negative
1236 * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1237 * changes the other way, allow runtime suspends.
1239 void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1241 int old_delay, old_use;
1243 spin_lock_irq(&dev->power.lock);
1244 old_delay = dev->power.autosuspend_delay;
1245 old_use = dev->power.use_autosuspend;
1246 dev->power.autosuspend_delay = delay;
1247 update_autosuspend(dev, old_delay, old_use);
1248 spin_unlock_irq(&dev->power.lock);
1250 EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1253 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1254 * @dev: Device to handle.
1255 * @use: New value for use_autosuspend.
1257 * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1258 * suspends as needed.
1260 void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1262 int old_delay, old_use;
1264 spin_lock_irq(&dev->power.lock);
1265 old_delay = dev->power.autosuspend_delay;
1266 old_use = dev->power.use_autosuspend;
1267 dev->power.use_autosuspend = use;
1268 update_autosuspend(dev, old_delay, old_use);
1269 spin_unlock_irq(&dev->power.lock);
1271 EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1274 * pm_runtime_init - Initialize runtime PM fields in given device object.
1275 * @dev: Device object to initialize.
1277 void pm_runtime_init(struct device *dev)
1279 dev->power.runtime_status = RPM_SUSPENDED;
1280 dev->power.idle_notification = false;
1282 dev->power.disable_depth = 1;
1283 atomic_set(&dev->power.usage_count, 0);
1285 dev->power.runtime_error = 0;
1287 atomic_set(&dev->power.child_count, 0);
1288 pm_suspend_ignore_children(dev, false);
1289 dev->power.runtime_auto = true;
1291 dev->power.request_pending = false;
1292 dev->power.request = RPM_REQ_NONE;
1293 dev->power.deferred_resume = false;
1294 dev->power.accounting_timestamp = jiffies;
1295 INIT_WORK(&dev->power.work, pm_runtime_work);
1297 dev->power.timer_expires = 0;
1298 setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
1299 (unsigned long)dev);
1301 init_waitqueue_head(&dev->power.wait_queue);
1305 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1306 * @dev: Device object being removed from device hierarchy.
1308 void pm_runtime_remove(struct device *dev)
1310 __pm_runtime_disable(dev, false);
1312 /* Change the status back to 'suspended' to match the initial status. */
1313 if (dev->power.runtime_status == RPM_ACTIVE)
1314 pm_runtime_set_suspended(dev);
1315 if (dev->power.irq_safe && dev->parent)
1316 pm_runtime_put_sync(dev->parent);