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_pm_qos_read_value(dev) < 0)
152 else if (dev->power.runtime_status == RPM_SUSPENDED)
159 * __rpm_callback - Run a given runtime PM callback for a given device.
160 * @cb: Runtime PM callback to run.
161 * @dev: Device to run the callback for.
163 static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
164 __releases(&dev->power.lock) __acquires(&dev->power.lock)
168 if (dev->power.irq_safe)
169 spin_unlock(&dev->power.lock);
171 spin_unlock_irq(&dev->power.lock);
175 if (dev->power.irq_safe)
176 spin_lock(&dev->power.lock);
178 spin_lock_irq(&dev->power.lock);
184 * rpm_idle - Notify device bus type if the device can be suspended.
185 * @dev: Device to notify the bus type about.
186 * @rpmflags: Flag bits.
188 * Check if the device's runtime PM status allows it to be suspended. If
189 * another idle notification has been started earlier, return immediately. If
190 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
191 * run the ->runtime_idle() callback directly.
193 * This function must be called under dev->power.lock with interrupts disabled.
195 static int rpm_idle(struct device *dev, int rpmflags)
197 int (*callback)(struct device *);
200 trace_rpm_idle(dev, rpmflags);
201 retval = rpm_check_suspend_allowed(dev);
203 ; /* Conditions are wrong. */
205 /* Idle notifications are allowed only in the RPM_ACTIVE state. */
206 else if (dev->power.runtime_status != RPM_ACTIVE)
210 * Any pending request other than an idle notification takes
211 * precedence over us, except that the timer may be running.
213 else if (dev->power.request_pending &&
214 dev->power.request > RPM_REQ_IDLE)
217 /* Act as though RPM_NOWAIT is always set. */
218 else if (dev->power.idle_notification)
219 retval = -EINPROGRESS;
223 /* Pending requests need to be canceled. */
224 dev->power.request = RPM_REQ_NONE;
226 if (dev->power.no_callbacks) {
227 /* Assume ->runtime_idle() callback would have suspended. */
228 retval = rpm_suspend(dev, rpmflags);
232 /* Carry out an asynchronous or a synchronous idle notification. */
233 if (rpmflags & RPM_ASYNC) {
234 dev->power.request = RPM_REQ_IDLE;
235 if (!dev->power.request_pending) {
236 dev->power.request_pending = true;
237 queue_work(pm_wq, &dev->power.work);
242 dev->power.idle_notification = true;
245 callback = dev->pm_domain->ops.runtime_idle;
246 else if (dev->type && dev->type->pm)
247 callback = dev->type->pm->runtime_idle;
248 else if (dev->class && dev->class->pm)
249 callback = dev->class->pm->runtime_idle;
250 else if (dev->bus && dev->bus->pm)
251 callback = dev->bus->pm->runtime_idle;
255 if (!callback && dev->driver && dev->driver->pm)
256 callback = dev->driver->pm->runtime_idle;
259 __rpm_callback(callback, dev);
261 dev->power.idle_notification = false;
262 wake_up_all(&dev->power.wait_queue);
265 trace_rpm_return_int(dev, _THIS_IP_, retval);
270 * rpm_callback - Run a given runtime PM callback for a given device.
271 * @cb: Runtime PM callback to run.
272 * @dev: Device to run the callback for.
274 static int rpm_callback(int (*cb)(struct device *), struct device *dev)
281 retval = __rpm_callback(cb, dev);
283 dev->power.runtime_error = retval;
284 return retval != -EACCES ? retval : -EIO;
288 * rpm_suspend - Carry out runtime suspend of given device.
289 * @dev: Device to suspend.
290 * @rpmflags: Flag bits.
292 * Check if the device's runtime PM status allows it to be suspended.
293 * Cancel a pending idle notification, autosuspend or suspend. If
294 * another suspend has been started earlier, either return immediately
295 * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
296 * flags. If the RPM_ASYNC flag is set then queue a suspend request;
297 * otherwise run the ->runtime_suspend() callback directly. When
298 * ->runtime_suspend succeeded, if a deferred resume was requested while
299 * the callback was running then carry it out, otherwise send an idle
300 * notification for its parent (if the suspend succeeded and both
301 * ignore_children of parent->power and irq_safe of dev->power are not set).
302 * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
303 * flag is set and the next autosuspend-delay expiration time is in the
304 * future, schedule another autosuspend attempt.
306 * This function must be called under dev->power.lock with interrupts disabled.
308 static int rpm_suspend(struct device *dev, int rpmflags)
309 __releases(&dev->power.lock) __acquires(&dev->power.lock)
311 int (*callback)(struct device *);
312 struct device *parent = NULL;
315 trace_rpm_suspend(dev, rpmflags);
318 retval = rpm_check_suspend_allowed(dev);
321 ; /* Conditions are wrong. */
323 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
324 else if (dev->power.runtime_status == RPM_RESUMING &&
325 !(rpmflags & RPM_ASYNC))
330 /* If the autosuspend_delay time hasn't expired yet, reschedule. */
331 if ((rpmflags & RPM_AUTO)
332 && dev->power.runtime_status != RPM_SUSPENDING) {
333 unsigned long expires = pm_runtime_autosuspend_expiration(dev);
336 /* Pending requests need to be canceled. */
337 dev->power.request = RPM_REQ_NONE;
340 * Optimization: If the timer is already running and is
341 * set to expire at or before the autosuspend delay,
342 * avoid the overhead of resetting it. Just let it
343 * expire; pm_suspend_timer_fn() will take care of the
346 if (!(dev->power.timer_expires && time_before_eq(
347 dev->power.timer_expires, expires))) {
348 dev->power.timer_expires = expires;
349 mod_timer(&dev->power.suspend_timer, expires);
351 dev->power.timer_autosuspends = 1;
356 /* Other scheduled or pending requests need to be canceled. */
357 pm_runtime_cancel_pending(dev);
359 if (dev->power.runtime_status == RPM_SUSPENDING) {
362 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
363 retval = -EINPROGRESS;
367 if (dev->power.irq_safe) {
368 spin_unlock(&dev->power.lock);
372 spin_lock(&dev->power.lock);
376 /* Wait for the other suspend running in parallel with us. */
378 prepare_to_wait(&dev->power.wait_queue, &wait,
379 TASK_UNINTERRUPTIBLE);
380 if (dev->power.runtime_status != RPM_SUSPENDING)
383 spin_unlock_irq(&dev->power.lock);
387 spin_lock_irq(&dev->power.lock);
389 finish_wait(&dev->power.wait_queue, &wait);
393 if (dev->power.no_callbacks)
394 goto no_callback; /* Assume success. */
396 /* Carry out an asynchronous or a synchronous suspend. */
397 if (rpmflags & RPM_ASYNC) {
398 dev->power.request = (rpmflags & RPM_AUTO) ?
399 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
400 if (!dev->power.request_pending) {
401 dev->power.request_pending = true;
402 queue_work(pm_wq, &dev->power.work);
407 __update_runtime_status(dev, RPM_SUSPENDING);
410 callback = dev->pm_domain->ops.runtime_suspend;
411 else if (dev->type && dev->type->pm)
412 callback = dev->type->pm->runtime_suspend;
413 else if (dev->class && dev->class->pm)
414 callback = dev->class->pm->runtime_suspend;
415 else if (dev->bus && dev->bus->pm)
416 callback = dev->bus->pm->runtime_suspend;
420 if (!callback && dev->driver && dev->driver->pm)
421 callback = dev->driver->pm->runtime_suspend;
423 retval = rpm_callback(callback, dev);
428 __update_runtime_status(dev, RPM_SUSPENDED);
429 pm_runtime_deactivate_timer(dev);
432 parent = dev->parent;
433 atomic_add_unless(&parent->power.child_count, -1, 0);
435 wake_up_all(&dev->power.wait_queue);
437 if (dev->power.deferred_resume) {
438 dev->power.deferred_resume = false;
444 /* Maybe the parent is now able to suspend. */
445 if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
446 spin_unlock(&dev->power.lock);
448 spin_lock(&parent->power.lock);
449 rpm_idle(parent, RPM_ASYNC);
450 spin_unlock(&parent->power.lock);
452 spin_lock(&dev->power.lock);
456 trace_rpm_return_int(dev, _THIS_IP_, retval);
461 __update_runtime_status(dev, RPM_ACTIVE);
462 dev->power.deferred_resume = false;
463 wake_up_all(&dev->power.wait_queue);
465 if (retval == -EAGAIN || retval == -EBUSY) {
466 dev->power.runtime_error = 0;
469 * If the callback routine failed an autosuspend, and
470 * if the last_busy time has been updated so that there
471 * is a new autosuspend expiration time, automatically
472 * reschedule another autosuspend.
474 if ((rpmflags & RPM_AUTO) &&
475 pm_runtime_autosuspend_expiration(dev) != 0)
478 pm_runtime_cancel_pending(dev);
484 * rpm_resume - Carry out runtime resume of given device.
485 * @dev: Device to resume.
486 * @rpmflags: Flag bits.
488 * Check if the device's runtime PM status allows it to be resumed. Cancel
489 * any scheduled or pending requests. If another resume has been started
490 * earlier, either return immediately or wait for it to finish, depending on the
491 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
492 * parallel with this function, either tell the other process to resume after
493 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
494 * flag is set then queue a resume request; otherwise run the
495 * ->runtime_resume() callback directly. Queue an idle notification for the
496 * device if the resume succeeded.
498 * This function must be called under dev->power.lock with interrupts disabled.
500 static int rpm_resume(struct device *dev, int rpmflags)
501 __releases(&dev->power.lock) __acquires(&dev->power.lock)
503 int (*callback)(struct device *);
504 struct device *parent = NULL;
507 trace_rpm_resume(dev, rpmflags);
510 if (dev->power.runtime_error)
512 else if (dev->power.disable_depth > 0)
518 * Other scheduled or pending requests need to be canceled. Small
519 * optimization: If an autosuspend timer is running, leave it running
520 * rather than cancelling it now only to restart it again in the near
523 dev->power.request = RPM_REQ_NONE;
524 if (!dev->power.timer_autosuspends)
525 pm_runtime_deactivate_timer(dev);
527 if (dev->power.runtime_status == RPM_ACTIVE) {
532 if (dev->power.runtime_status == RPM_RESUMING
533 || dev->power.runtime_status == RPM_SUSPENDING) {
536 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
537 if (dev->power.runtime_status == RPM_SUSPENDING)
538 dev->power.deferred_resume = true;
540 retval = -EINPROGRESS;
544 if (dev->power.irq_safe) {
545 spin_unlock(&dev->power.lock);
549 spin_lock(&dev->power.lock);
553 /* Wait for the operation carried out in parallel with us. */
555 prepare_to_wait(&dev->power.wait_queue, &wait,
556 TASK_UNINTERRUPTIBLE);
557 if (dev->power.runtime_status != RPM_RESUMING
558 && dev->power.runtime_status != RPM_SUSPENDING)
561 spin_unlock_irq(&dev->power.lock);
565 spin_lock_irq(&dev->power.lock);
567 finish_wait(&dev->power.wait_queue, &wait);
572 * See if we can skip waking up the parent. This is safe only if
573 * power.no_callbacks is set, because otherwise we don't know whether
574 * the resume will actually succeed.
576 if (dev->power.no_callbacks && !parent && dev->parent) {
577 spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
578 if (dev->parent->power.disable_depth > 0
579 || dev->parent->power.ignore_children
580 || dev->parent->power.runtime_status == RPM_ACTIVE) {
581 atomic_inc(&dev->parent->power.child_count);
582 spin_unlock(&dev->parent->power.lock);
584 goto no_callback; /* Assume success. */
586 spin_unlock(&dev->parent->power.lock);
589 /* Carry out an asynchronous or a synchronous resume. */
590 if (rpmflags & RPM_ASYNC) {
591 dev->power.request = RPM_REQ_RESUME;
592 if (!dev->power.request_pending) {
593 dev->power.request_pending = true;
594 queue_work(pm_wq, &dev->power.work);
600 if (!parent && dev->parent) {
602 * Increment the parent's usage counter and resume it if
603 * necessary. Not needed if dev is irq-safe; then the
604 * parent is permanently resumed.
606 parent = dev->parent;
607 if (dev->power.irq_safe)
609 spin_unlock(&dev->power.lock);
611 pm_runtime_get_noresume(parent);
613 spin_lock(&parent->power.lock);
615 * We can resume if the parent's runtime PM is disabled or it
616 * is set to ignore children.
618 if (!parent->power.disable_depth
619 && !parent->power.ignore_children) {
620 rpm_resume(parent, 0);
621 if (parent->power.runtime_status != RPM_ACTIVE)
624 spin_unlock(&parent->power.lock);
626 spin_lock(&dev->power.lock);
633 if (dev->power.no_callbacks)
634 goto no_callback; /* Assume success. */
636 __update_runtime_status(dev, RPM_RESUMING);
639 callback = dev->pm_domain->ops.runtime_resume;
640 else if (dev->type && dev->type->pm)
641 callback = dev->type->pm->runtime_resume;
642 else if (dev->class && dev->class->pm)
643 callback = dev->class->pm->runtime_resume;
644 else if (dev->bus && dev->bus->pm)
645 callback = dev->bus->pm->runtime_resume;
649 if (!callback && dev->driver && dev->driver->pm)
650 callback = dev->driver->pm->runtime_resume;
652 retval = rpm_callback(callback, dev);
654 __update_runtime_status(dev, RPM_SUSPENDED);
655 pm_runtime_cancel_pending(dev);
658 __update_runtime_status(dev, RPM_ACTIVE);
660 atomic_inc(&parent->power.child_count);
662 wake_up_all(&dev->power.wait_queue);
665 rpm_idle(dev, RPM_ASYNC);
668 if (parent && !dev->power.irq_safe) {
669 spin_unlock_irq(&dev->power.lock);
671 pm_runtime_put(parent);
673 spin_lock_irq(&dev->power.lock);
676 trace_rpm_return_int(dev, _THIS_IP_, retval);
682 * pm_runtime_work - Universal runtime PM work function.
683 * @work: Work structure used for scheduling the execution of this function.
685 * Use @work to get the device object the work is to be done for, determine what
686 * is to be done and execute the appropriate runtime PM function.
688 static void pm_runtime_work(struct work_struct *work)
690 struct device *dev = container_of(work, struct device, power.work);
691 enum rpm_request req;
693 spin_lock_irq(&dev->power.lock);
695 if (!dev->power.request_pending)
698 req = dev->power.request;
699 dev->power.request = RPM_REQ_NONE;
700 dev->power.request_pending = false;
706 rpm_idle(dev, RPM_NOWAIT);
708 case RPM_REQ_SUSPEND:
709 rpm_suspend(dev, RPM_NOWAIT);
711 case RPM_REQ_AUTOSUSPEND:
712 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
715 rpm_resume(dev, RPM_NOWAIT);
720 spin_unlock_irq(&dev->power.lock);
724 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
725 * @data: Device pointer passed by pm_schedule_suspend().
727 * Check if the time is right and queue a suspend request.
729 static void pm_suspend_timer_fn(unsigned long data)
731 struct device *dev = (struct device *)data;
733 unsigned long expires;
735 spin_lock_irqsave(&dev->power.lock, flags);
737 expires = dev->power.timer_expires;
738 /* If 'expire' is after 'jiffies' we've been called too early. */
739 if (expires > 0 && !time_after(expires, jiffies)) {
740 dev->power.timer_expires = 0;
741 rpm_suspend(dev, dev->power.timer_autosuspends ?
742 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
745 spin_unlock_irqrestore(&dev->power.lock, flags);
749 * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
750 * @dev: Device to suspend.
751 * @delay: Time to wait before submitting a suspend request, in milliseconds.
753 int pm_schedule_suspend(struct device *dev, unsigned int delay)
758 spin_lock_irqsave(&dev->power.lock, flags);
761 retval = rpm_suspend(dev, RPM_ASYNC);
765 retval = rpm_check_suspend_allowed(dev);
769 /* Other scheduled or pending requests need to be canceled. */
770 pm_runtime_cancel_pending(dev);
772 dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
773 dev->power.timer_expires += !dev->power.timer_expires;
774 dev->power.timer_autosuspends = 0;
775 mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
778 spin_unlock_irqrestore(&dev->power.lock, flags);
782 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
785 * __pm_runtime_idle - Entry point for runtime idle operations.
786 * @dev: Device to send idle notification for.
787 * @rpmflags: Flag bits.
789 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
790 * return immediately if it is larger than zero. Then carry out an idle
791 * notification, either synchronous or asynchronous.
793 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
794 * or if pm_runtime_irq_safe() has been called.
796 int __pm_runtime_idle(struct device *dev, int rpmflags)
801 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
803 if (rpmflags & RPM_GET_PUT) {
804 if (!atomic_dec_and_test(&dev->power.usage_count))
808 spin_lock_irqsave(&dev->power.lock, flags);
809 retval = rpm_idle(dev, rpmflags);
810 spin_unlock_irqrestore(&dev->power.lock, flags);
814 EXPORT_SYMBOL_GPL(__pm_runtime_idle);
817 * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
818 * @dev: Device to suspend.
819 * @rpmflags: Flag bits.
821 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
822 * return immediately if it is larger than zero. Then carry out a suspend,
823 * either synchronous or asynchronous.
825 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
826 * or if pm_runtime_irq_safe() has been called.
828 int __pm_runtime_suspend(struct device *dev, int rpmflags)
833 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
835 if (rpmflags & RPM_GET_PUT) {
836 if (!atomic_dec_and_test(&dev->power.usage_count))
840 spin_lock_irqsave(&dev->power.lock, flags);
841 retval = rpm_suspend(dev, rpmflags);
842 spin_unlock_irqrestore(&dev->power.lock, flags);
846 EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
849 * __pm_runtime_resume - Entry point for runtime resume operations.
850 * @dev: Device to resume.
851 * @rpmflags: Flag bits.
853 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
854 * carry out a resume, either synchronous or asynchronous.
856 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
857 * or if pm_runtime_irq_safe() has been called.
859 int __pm_runtime_resume(struct device *dev, int rpmflags)
864 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
866 if (rpmflags & RPM_GET_PUT)
867 atomic_inc(&dev->power.usage_count);
869 spin_lock_irqsave(&dev->power.lock, flags);
870 retval = rpm_resume(dev, rpmflags);
871 spin_unlock_irqrestore(&dev->power.lock, flags);
875 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
878 * __pm_runtime_set_status - Set runtime PM status of a device.
879 * @dev: Device to handle.
880 * @status: New runtime PM status of the device.
882 * If runtime PM of the device is disabled or its power.runtime_error field is
883 * different from zero, the status may be changed either to RPM_ACTIVE, or to
884 * RPM_SUSPENDED, as long as that reflects the actual state of the device.
885 * However, if the device has a parent and the parent is not active, and the
886 * parent's power.ignore_children flag is unset, the device's status cannot be
887 * set to RPM_ACTIVE, so -EBUSY is returned in that case.
889 * If successful, __pm_runtime_set_status() clears the power.runtime_error field
890 * and the device parent's counter of unsuspended children is modified to
891 * reflect the new status. If the new status is RPM_SUSPENDED, an idle
892 * notification request for the parent is submitted.
894 int __pm_runtime_set_status(struct device *dev, unsigned int status)
896 struct device *parent = dev->parent;
898 bool notify_parent = false;
901 if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
904 spin_lock_irqsave(&dev->power.lock, flags);
906 if (!dev->power.runtime_error && !dev->power.disable_depth) {
911 if (dev->power.runtime_status == status)
914 if (status == RPM_SUSPENDED) {
915 /* It always is possible to set the status to 'suspended'. */
917 atomic_add_unless(&parent->power.child_count, -1, 0);
918 notify_parent = !parent->power.ignore_children;
924 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
927 * It is invalid to put an active child under a parent that is
928 * not active, has runtime PM enabled and the
929 * 'power.ignore_children' flag unset.
931 if (!parent->power.disable_depth
932 && !parent->power.ignore_children
933 && parent->power.runtime_status != RPM_ACTIVE)
935 else if (dev->power.runtime_status == RPM_SUSPENDED)
936 atomic_inc(&parent->power.child_count);
938 spin_unlock(&parent->power.lock);
945 __update_runtime_status(dev, status);
946 dev->power.runtime_error = 0;
948 spin_unlock_irqrestore(&dev->power.lock, flags);
951 pm_request_idle(parent);
955 EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
958 * __pm_runtime_barrier - Cancel pending requests and wait for completions.
959 * @dev: Device to handle.
961 * Flush all pending requests for the device from pm_wq and wait for all
962 * runtime PM operations involving the device in progress to complete.
964 * Should be called under dev->power.lock with interrupts disabled.
966 static void __pm_runtime_barrier(struct device *dev)
968 pm_runtime_deactivate_timer(dev);
970 if (dev->power.request_pending) {
971 dev->power.request = RPM_REQ_NONE;
972 spin_unlock_irq(&dev->power.lock);
974 cancel_work_sync(&dev->power.work);
976 spin_lock_irq(&dev->power.lock);
977 dev->power.request_pending = false;
980 if (dev->power.runtime_status == RPM_SUSPENDING
981 || dev->power.runtime_status == RPM_RESUMING
982 || dev->power.idle_notification) {
985 /* Suspend, wake-up or idle notification in progress. */
987 prepare_to_wait(&dev->power.wait_queue, &wait,
988 TASK_UNINTERRUPTIBLE);
989 if (dev->power.runtime_status != RPM_SUSPENDING
990 && dev->power.runtime_status != RPM_RESUMING
991 && !dev->power.idle_notification)
993 spin_unlock_irq(&dev->power.lock);
997 spin_lock_irq(&dev->power.lock);
999 finish_wait(&dev->power.wait_queue, &wait);
1004 * pm_runtime_barrier - Flush pending requests and wait for completions.
1005 * @dev: Device to handle.
1007 * Prevent the device from being suspended by incrementing its usage counter and
1008 * if there's a pending resume request for the device, wake the device up.
1009 * Next, make sure that all pending requests for the device have been flushed
1010 * from pm_wq and wait for all runtime PM operations involving the device in
1011 * progress to complete.
1014 * 1, if there was a resume request pending and the device had to be woken up,
1017 int pm_runtime_barrier(struct device *dev)
1021 pm_runtime_get_noresume(dev);
1022 spin_lock_irq(&dev->power.lock);
1024 if (dev->power.request_pending
1025 && dev->power.request == RPM_REQ_RESUME) {
1030 __pm_runtime_barrier(dev);
1032 spin_unlock_irq(&dev->power.lock);
1033 pm_runtime_put_noidle(dev);
1037 EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1040 * __pm_runtime_disable - Disable runtime PM of a device.
1041 * @dev: Device to handle.
1042 * @check_resume: If set, check if there's a resume request for the device.
1044 * Increment power.disable_depth for the device and if was zero previously,
1045 * cancel all pending runtime PM requests for the device and wait for all
1046 * operations in progress to complete. The device can be either active or
1047 * suspended after its runtime PM has been disabled.
1049 * If @check_resume is set and there's a resume request pending when
1050 * __pm_runtime_disable() is called and power.disable_depth is zero, the
1051 * function will wake up the device before disabling its runtime PM.
1053 void __pm_runtime_disable(struct device *dev, bool check_resume)
1055 spin_lock_irq(&dev->power.lock);
1057 if (dev->power.disable_depth > 0) {
1058 dev->power.disable_depth++;
1063 * Wake up the device if there's a resume request pending, because that
1064 * means there probably is some I/O to process and disabling runtime PM
1065 * shouldn't prevent the device from processing the I/O.
1067 if (check_resume && dev->power.request_pending
1068 && dev->power.request == RPM_REQ_RESUME) {
1070 * Prevent suspends and idle notifications from being carried
1071 * out after we have woken up the device.
1073 pm_runtime_get_noresume(dev);
1077 pm_runtime_put_noidle(dev);
1080 if (!dev->power.disable_depth++)
1081 __pm_runtime_barrier(dev);
1084 spin_unlock_irq(&dev->power.lock);
1086 EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1089 * pm_runtime_enable - Enable runtime PM of a device.
1090 * @dev: Device to handle.
1092 void pm_runtime_enable(struct device *dev)
1094 unsigned long flags;
1096 spin_lock_irqsave(&dev->power.lock, flags);
1098 if (dev->power.disable_depth > 0)
1099 dev->power.disable_depth--;
1101 dev_warn(dev, "Unbalanced %s!\n", __func__);
1103 spin_unlock_irqrestore(&dev->power.lock, flags);
1105 EXPORT_SYMBOL_GPL(pm_runtime_enable);
1108 * pm_runtime_forbid - Block runtime PM of a device.
1109 * @dev: Device to handle.
1111 * Increase the device's usage count and clear its power.runtime_auto flag,
1112 * so that it cannot be suspended at run time until pm_runtime_allow() is called
1115 void pm_runtime_forbid(struct device *dev)
1117 spin_lock_irq(&dev->power.lock);
1118 if (!dev->power.runtime_auto)
1121 dev->power.runtime_auto = false;
1122 atomic_inc(&dev->power.usage_count);
1126 spin_unlock_irq(&dev->power.lock);
1128 EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1131 * pm_runtime_allow - Unblock runtime PM of a device.
1132 * @dev: Device to handle.
1134 * Decrease the device's usage count and set its power.runtime_auto flag.
1136 void pm_runtime_allow(struct device *dev)
1138 spin_lock_irq(&dev->power.lock);
1139 if (dev->power.runtime_auto)
1142 dev->power.runtime_auto = true;
1143 if (atomic_dec_and_test(&dev->power.usage_count))
1144 rpm_idle(dev, RPM_AUTO);
1147 spin_unlock_irq(&dev->power.lock);
1149 EXPORT_SYMBOL_GPL(pm_runtime_allow);
1152 * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1153 * @dev: Device to handle.
1155 * Set the power.no_callbacks flag, which tells the PM core that this
1156 * device is power-managed through its parent and has no runtime PM
1157 * callbacks of its own. The runtime sysfs attributes will be removed.
1159 void pm_runtime_no_callbacks(struct device *dev)
1161 spin_lock_irq(&dev->power.lock);
1162 dev->power.no_callbacks = 1;
1163 spin_unlock_irq(&dev->power.lock);
1164 if (device_is_registered(dev))
1165 rpm_sysfs_remove(dev);
1167 EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1170 * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1171 * @dev: Device to handle
1173 * Set the power.irq_safe flag, which tells the PM core that the
1174 * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1175 * always be invoked with the spinlock held and interrupts disabled. It also
1176 * causes the parent's usage counter to be permanently incremented, preventing
1177 * the parent from runtime suspending -- otherwise an irq-safe child might have
1178 * to wait for a non-irq-safe parent.
1180 void pm_runtime_irq_safe(struct device *dev)
1183 pm_runtime_get_sync(dev->parent);
1184 spin_lock_irq(&dev->power.lock);
1185 dev->power.irq_safe = 1;
1186 spin_unlock_irq(&dev->power.lock);
1188 EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1191 * update_autosuspend - Handle a change to a device's autosuspend settings.
1192 * @dev: Device to handle.
1193 * @old_delay: The former autosuspend_delay value.
1194 * @old_use: The former use_autosuspend value.
1196 * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1197 * set; otherwise allow it. Send an idle notification if suspends are allowed.
1199 * This function must be called under dev->power.lock with interrupts disabled.
1201 static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1203 int delay = dev->power.autosuspend_delay;
1205 /* Should runtime suspend be prevented now? */
1206 if (dev->power.use_autosuspend && delay < 0) {
1208 /* If it used to be allowed then prevent it. */
1209 if (!old_use || old_delay >= 0) {
1210 atomic_inc(&dev->power.usage_count);
1215 /* Runtime suspend should be allowed now. */
1218 /* If it used to be prevented then allow it. */
1219 if (old_use && old_delay < 0)
1220 atomic_dec(&dev->power.usage_count);
1222 /* Maybe we can autosuspend now. */
1223 rpm_idle(dev, RPM_AUTO);
1228 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1229 * @dev: Device to handle.
1230 * @delay: Value of the new delay in milliseconds.
1232 * Set the device's power.autosuspend_delay value. If it changes to negative
1233 * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1234 * changes the other way, allow runtime suspends.
1236 void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1238 int old_delay, old_use;
1240 spin_lock_irq(&dev->power.lock);
1241 old_delay = dev->power.autosuspend_delay;
1242 old_use = dev->power.use_autosuspend;
1243 dev->power.autosuspend_delay = delay;
1244 update_autosuspend(dev, old_delay, old_use);
1245 spin_unlock_irq(&dev->power.lock);
1247 EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1250 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1251 * @dev: Device to handle.
1252 * @use: New value for use_autosuspend.
1254 * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1255 * suspends as needed.
1257 void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1259 int old_delay, old_use;
1261 spin_lock_irq(&dev->power.lock);
1262 old_delay = dev->power.autosuspend_delay;
1263 old_use = dev->power.use_autosuspend;
1264 dev->power.use_autosuspend = use;
1265 update_autosuspend(dev, old_delay, old_use);
1266 spin_unlock_irq(&dev->power.lock);
1268 EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1271 * pm_runtime_init - Initialize runtime PM fields in given device object.
1272 * @dev: Device object to initialize.
1274 void pm_runtime_init(struct device *dev)
1276 dev->power.runtime_status = RPM_SUSPENDED;
1277 dev->power.idle_notification = false;
1279 dev->power.disable_depth = 1;
1280 atomic_set(&dev->power.usage_count, 0);
1282 dev->power.runtime_error = 0;
1284 atomic_set(&dev->power.child_count, 0);
1285 pm_suspend_ignore_children(dev, false);
1286 dev->power.runtime_auto = true;
1288 dev->power.request_pending = false;
1289 dev->power.request = RPM_REQ_NONE;
1290 dev->power.deferred_resume = false;
1291 dev->power.accounting_timestamp = jiffies;
1292 INIT_WORK(&dev->power.work, pm_runtime_work);
1294 dev->power.timer_expires = 0;
1295 setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
1296 (unsigned long)dev);
1298 init_waitqueue_head(&dev->power.wait_queue);
1302 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1303 * @dev: Device object being removed from device hierarchy.
1305 void pm_runtime_remove(struct device *dev)
1307 __pm_runtime_disable(dev, false);
1309 /* Change the status back to 'suspended' to match the initial status. */
1310 if (dev->power.runtime_status == RPM_ACTIVE)
1311 pm_runtime_set_suspended(dev);
1312 if (dev->power.irq_safe && dev->parent)
1313 pm_runtime_put_sync(dev->parent);