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);
127 static int dev_memalloc_noio(struct device *dev, void *data)
129 return dev->power.memalloc_noio;
133 * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
134 * @dev: Device to handle.
135 * @enable: True for setting the flag and False for clearing the flag.
137 * Set the flag for all devices in the path from the device to the
138 * root device in the device tree if @enable is true, otherwise clear
139 * the flag for devices in the path whose siblings don't set the flag.
141 * The function should only be called by block device, or network
142 * device driver for solving the deadlock problem during runtime
145 * If memory allocation with GFP_KERNEL is called inside runtime
146 * resume/suspend callback of any one of its ancestors(or the
147 * block device itself), the deadlock may be triggered inside the
148 * memory allocation since it might not complete until the block
149 * device becomes active and the involed page I/O finishes. The
150 * situation is pointed out first by Alan Stern. Network device
151 * are involved in iSCSI kind of situation.
153 * The lock of dev_hotplug_mutex is held in the function for handling
154 * hotplug race because pm_runtime_set_memalloc_noio() may be called
157 * The function should be called between device_add() and device_del()
158 * on the affected device(block/network device).
160 void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
162 static DEFINE_MUTEX(dev_hotplug_mutex);
164 mutex_lock(&dev_hotplug_mutex);
168 /* hold power lock since bitfield is not SMP-safe. */
169 spin_lock_irq(&dev->power.lock);
170 enabled = dev->power.memalloc_noio;
171 dev->power.memalloc_noio = enable;
172 spin_unlock_irq(&dev->power.lock);
175 * not need to enable ancestors any more if the device
178 if (enabled && enable)
184 * clear flag of the parent device only if all the
185 * children don't set the flag because ancestor's
186 * flag was set by any one of the descendants.
188 if (!dev || (!enable &&
189 device_for_each_child(dev, NULL,
193 mutex_unlock(&dev_hotplug_mutex);
195 EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
198 * rpm_check_suspend_allowed - Test whether a device may be suspended.
199 * @dev: Device to test.
201 static int rpm_check_suspend_allowed(struct device *dev)
205 if (dev->power.runtime_error)
207 else if (dev->power.disable_depth > 0)
209 else if (atomic_read(&dev->power.usage_count) > 0)
211 else if (!pm_children_suspended(dev))
214 /* Pending resume requests take precedence over suspends. */
215 else if ((dev->power.deferred_resume
216 && dev->power.runtime_status == RPM_SUSPENDING)
217 || (dev->power.request_pending
218 && dev->power.request == RPM_REQ_RESUME))
220 else if (__dev_pm_qos_read_value(dev) < 0)
222 else if (dev->power.runtime_status == RPM_SUSPENDED)
229 * __rpm_callback - Run a given runtime PM callback for a given device.
230 * @cb: Runtime PM callback to run.
231 * @dev: Device to run the callback for.
233 static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
234 __releases(&dev->power.lock) __acquires(&dev->power.lock)
238 if (dev->power.irq_safe)
239 spin_unlock(&dev->power.lock);
241 spin_unlock_irq(&dev->power.lock);
245 if (dev->power.irq_safe)
246 spin_lock(&dev->power.lock);
248 spin_lock_irq(&dev->power.lock);
254 * rpm_idle - Notify device bus type if the device can be suspended.
255 * @dev: Device to notify the bus type about.
256 * @rpmflags: Flag bits.
258 * Check if the device's runtime PM status allows it to be suspended. If
259 * another idle notification has been started earlier, return immediately. If
260 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
261 * run the ->runtime_idle() callback directly.
263 * This function must be called under dev->power.lock with interrupts disabled.
265 static int rpm_idle(struct device *dev, int rpmflags)
267 int (*callback)(struct device *);
270 trace_rpm_idle(dev, rpmflags);
271 retval = rpm_check_suspend_allowed(dev);
273 ; /* Conditions are wrong. */
275 /* Idle notifications are allowed only in the RPM_ACTIVE state. */
276 else if (dev->power.runtime_status != RPM_ACTIVE)
280 * Any pending request other than an idle notification takes
281 * precedence over us, except that the timer may be running.
283 else if (dev->power.request_pending &&
284 dev->power.request > RPM_REQ_IDLE)
287 /* Act as though RPM_NOWAIT is always set. */
288 else if (dev->power.idle_notification)
289 retval = -EINPROGRESS;
293 /* Pending requests need to be canceled. */
294 dev->power.request = RPM_REQ_NONE;
296 if (dev->power.no_callbacks) {
297 /* Assume ->runtime_idle() callback would have suspended. */
298 retval = rpm_suspend(dev, rpmflags);
302 /* Carry out an asynchronous or a synchronous idle notification. */
303 if (rpmflags & RPM_ASYNC) {
304 dev->power.request = RPM_REQ_IDLE;
305 if (!dev->power.request_pending) {
306 dev->power.request_pending = true;
307 queue_work(pm_wq, &dev->power.work);
312 dev->power.idle_notification = true;
315 callback = dev->pm_domain->ops.runtime_idle;
316 else if (dev->type && dev->type->pm)
317 callback = dev->type->pm->runtime_idle;
318 else if (dev->class && dev->class->pm)
319 callback = dev->class->pm->runtime_idle;
320 else if (dev->bus && dev->bus->pm)
321 callback = dev->bus->pm->runtime_idle;
325 if (!callback && dev->driver && dev->driver->pm)
326 callback = dev->driver->pm->runtime_idle;
329 __rpm_callback(callback, dev);
331 dev->power.idle_notification = false;
332 wake_up_all(&dev->power.wait_queue);
335 trace_rpm_return_int(dev, _THIS_IP_, retval);
340 * rpm_callback - Run a given runtime PM callback for a given device.
341 * @cb: Runtime PM callback to run.
342 * @dev: Device to run the callback for.
344 static int rpm_callback(int (*cb)(struct device *), struct device *dev)
351 retval = __rpm_callback(cb, dev);
353 dev->power.runtime_error = retval;
354 return retval != -EACCES ? retval : -EIO;
358 * rpm_suspend - Carry out runtime suspend of given device.
359 * @dev: Device to suspend.
360 * @rpmflags: Flag bits.
362 * Check if the device's runtime PM status allows it to be suspended.
363 * Cancel a pending idle notification, autosuspend or suspend. If
364 * another suspend has been started earlier, either return immediately
365 * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
366 * flags. If the RPM_ASYNC flag is set then queue a suspend request;
367 * otherwise run the ->runtime_suspend() callback directly. When
368 * ->runtime_suspend succeeded, if a deferred resume was requested while
369 * the callback was running then carry it out, otherwise send an idle
370 * notification for its parent (if the suspend succeeded and both
371 * ignore_children of parent->power and irq_safe of dev->power are not set).
372 * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
373 * flag is set and the next autosuspend-delay expiration time is in the
374 * future, schedule another autosuspend attempt.
376 * This function must be called under dev->power.lock with interrupts disabled.
378 static int rpm_suspend(struct device *dev, int rpmflags)
379 __releases(&dev->power.lock) __acquires(&dev->power.lock)
381 int (*callback)(struct device *);
382 struct device *parent = NULL;
385 trace_rpm_suspend(dev, rpmflags);
388 retval = rpm_check_suspend_allowed(dev);
391 ; /* Conditions are wrong. */
393 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
394 else if (dev->power.runtime_status == RPM_RESUMING &&
395 !(rpmflags & RPM_ASYNC))
400 /* If the autosuspend_delay time hasn't expired yet, reschedule. */
401 if ((rpmflags & RPM_AUTO)
402 && dev->power.runtime_status != RPM_SUSPENDING) {
403 unsigned long expires = pm_runtime_autosuspend_expiration(dev);
406 /* Pending requests need to be canceled. */
407 dev->power.request = RPM_REQ_NONE;
410 * Optimization: If the timer is already running and is
411 * set to expire at or before the autosuspend delay,
412 * avoid the overhead of resetting it. Just let it
413 * expire; pm_suspend_timer_fn() will take care of the
416 if (!(dev->power.timer_expires && time_before_eq(
417 dev->power.timer_expires, expires))) {
418 dev->power.timer_expires = expires;
419 mod_timer(&dev->power.suspend_timer, expires);
421 dev->power.timer_autosuspends = 1;
426 /* Other scheduled or pending requests need to be canceled. */
427 pm_runtime_cancel_pending(dev);
429 if (dev->power.runtime_status == RPM_SUSPENDING) {
432 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
433 retval = -EINPROGRESS;
437 if (dev->power.irq_safe) {
438 spin_unlock(&dev->power.lock);
442 spin_lock(&dev->power.lock);
446 /* Wait for the other suspend running in parallel with us. */
448 prepare_to_wait(&dev->power.wait_queue, &wait,
449 TASK_UNINTERRUPTIBLE);
450 if (dev->power.runtime_status != RPM_SUSPENDING)
453 spin_unlock_irq(&dev->power.lock);
457 spin_lock_irq(&dev->power.lock);
459 finish_wait(&dev->power.wait_queue, &wait);
463 if (dev->power.no_callbacks)
464 goto no_callback; /* Assume success. */
466 /* Carry out an asynchronous or a synchronous suspend. */
467 if (rpmflags & RPM_ASYNC) {
468 dev->power.request = (rpmflags & RPM_AUTO) ?
469 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
470 if (!dev->power.request_pending) {
471 dev->power.request_pending = true;
472 queue_work(pm_wq, &dev->power.work);
477 __update_runtime_status(dev, RPM_SUSPENDING);
480 callback = dev->pm_domain->ops.runtime_suspend;
481 else if (dev->type && dev->type->pm)
482 callback = dev->type->pm->runtime_suspend;
483 else if (dev->class && dev->class->pm)
484 callback = dev->class->pm->runtime_suspend;
485 else if (dev->bus && dev->bus->pm)
486 callback = dev->bus->pm->runtime_suspend;
490 if (!callback && dev->driver && dev->driver->pm)
491 callback = dev->driver->pm->runtime_suspend;
493 retval = rpm_callback(callback, dev);
498 __update_runtime_status(dev, RPM_SUSPENDED);
499 pm_runtime_deactivate_timer(dev);
502 parent = dev->parent;
503 atomic_add_unless(&parent->power.child_count, -1, 0);
505 wake_up_all(&dev->power.wait_queue);
507 if (dev->power.deferred_resume) {
508 dev->power.deferred_resume = false;
514 /* Maybe the parent is now able to suspend. */
515 if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
516 spin_unlock(&dev->power.lock);
518 spin_lock(&parent->power.lock);
519 rpm_idle(parent, RPM_ASYNC);
520 spin_unlock(&parent->power.lock);
522 spin_lock(&dev->power.lock);
526 trace_rpm_return_int(dev, _THIS_IP_, retval);
531 __update_runtime_status(dev, RPM_ACTIVE);
532 dev->power.deferred_resume = false;
533 wake_up_all(&dev->power.wait_queue);
535 if (retval == -EAGAIN || retval == -EBUSY) {
536 dev->power.runtime_error = 0;
539 * If the callback routine failed an autosuspend, and
540 * if the last_busy time has been updated so that there
541 * is a new autosuspend expiration time, automatically
542 * reschedule another autosuspend.
544 if ((rpmflags & RPM_AUTO) &&
545 pm_runtime_autosuspend_expiration(dev) != 0)
548 pm_runtime_cancel_pending(dev);
554 * rpm_resume - Carry out runtime resume of given device.
555 * @dev: Device to resume.
556 * @rpmflags: Flag bits.
558 * Check if the device's runtime PM status allows it to be resumed. Cancel
559 * any scheduled or pending requests. If another resume has been started
560 * earlier, either return immediately or wait for it to finish, depending on the
561 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
562 * parallel with this function, either tell the other process to resume after
563 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
564 * flag is set then queue a resume request; otherwise run the
565 * ->runtime_resume() callback directly. Queue an idle notification for the
566 * device if the resume succeeded.
568 * This function must be called under dev->power.lock with interrupts disabled.
570 static int rpm_resume(struct device *dev, int rpmflags)
571 __releases(&dev->power.lock) __acquires(&dev->power.lock)
573 int (*callback)(struct device *);
574 struct device *parent = NULL;
577 trace_rpm_resume(dev, rpmflags);
580 if (dev->power.runtime_error)
582 else if (dev->power.disable_depth == 1 && dev->power.is_suspended
583 && dev->power.runtime_status == RPM_ACTIVE)
585 else if (dev->power.disable_depth > 0)
591 * Other scheduled or pending requests need to be canceled. Small
592 * optimization: If an autosuspend timer is running, leave it running
593 * rather than cancelling it now only to restart it again in the near
596 dev->power.request = RPM_REQ_NONE;
597 if (!dev->power.timer_autosuspends)
598 pm_runtime_deactivate_timer(dev);
600 if (dev->power.runtime_status == RPM_ACTIVE) {
605 if (dev->power.runtime_status == RPM_RESUMING
606 || dev->power.runtime_status == RPM_SUSPENDING) {
609 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
610 if (dev->power.runtime_status == RPM_SUSPENDING)
611 dev->power.deferred_resume = true;
613 retval = -EINPROGRESS;
617 if (dev->power.irq_safe) {
618 spin_unlock(&dev->power.lock);
622 spin_lock(&dev->power.lock);
626 /* Wait for the operation carried out in parallel with us. */
628 prepare_to_wait(&dev->power.wait_queue, &wait,
629 TASK_UNINTERRUPTIBLE);
630 if (dev->power.runtime_status != RPM_RESUMING
631 && dev->power.runtime_status != RPM_SUSPENDING)
634 spin_unlock_irq(&dev->power.lock);
638 spin_lock_irq(&dev->power.lock);
640 finish_wait(&dev->power.wait_queue, &wait);
645 * See if we can skip waking up the parent. This is safe only if
646 * power.no_callbacks is set, because otherwise we don't know whether
647 * the resume will actually succeed.
649 if (dev->power.no_callbacks && !parent && dev->parent) {
650 spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
651 if (dev->parent->power.disable_depth > 0
652 || dev->parent->power.ignore_children
653 || dev->parent->power.runtime_status == RPM_ACTIVE) {
654 atomic_inc(&dev->parent->power.child_count);
655 spin_unlock(&dev->parent->power.lock);
657 goto no_callback; /* Assume success. */
659 spin_unlock(&dev->parent->power.lock);
662 /* Carry out an asynchronous or a synchronous resume. */
663 if (rpmflags & RPM_ASYNC) {
664 dev->power.request = RPM_REQ_RESUME;
665 if (!dev->power.request_pending) {
666 dev->power.request_pending = true;
667 queue_work(pm_wq, &dev->power.work);
673 if (!parent && dev->parent) {
675 * Increment the parent's usage counter and resume it if
676 * necessary. Not needed if dev is irq-safe; then the
677 * parent is permanently resumed.
679 parent = dev->parent;
680 if (dev->power.irq_safe)
682 spin_unlock(&dev->power.lock);
684 pm_runtime_get_noresume(parent);
686 spin_lock(&parent->power.lock);
688 * We can resume if the parent's runtime PM is disabled or it
689 * is set to ignore children.
691 if (!parent->power.disable_depth
692 && !parent->power.ignore_children) {
693 rpm_resume(parent, 0);
694 if (parent->power.runtime_status != RPM_ACTIVE)
697 spin_unlock(&parent->power.lock);
699 spin_lock(&dev->power.lock);
706 if (dev->power.no_callbacks)
707 goto no_callback; /* Assume success. */
709 __update_runtime_status(dev, RPM_RESUMING);
712 callback = dev->pm_domain->ops.runtime_resume;
713 else if (dev->type && dev->type->pm)
714 callback = dev->type->pm->runtime_resume;
715 else if (dev->class && dev->class->pm)
716 callback = dev->class->pm->runtime_resume;
717 else if (dev->bus && dev->bus->pm)
718 callback = dev->bus->pm->runtime_resume;
722 if (!callback && dev->driver && dev->driver->pm)
723 callback = dev->driver->pm->runtime_resume;
725 retval = rpm_callback(callback, dev);
727 __update_runtime_status(dev, RPM_SUSPENDED);
728 pm_runtime_cancel_pending(dev);
731 __update_runtime_status(dev, RPM_ACTIVE);
733 atomic_inc(&parent->power.child_count);
735 wake_up_all(&dev->power.wait_queue);
738 rpm_idle(dev, RPM_ASYNC);
741 if (parent && !dev->power.irq_safe) {
742 spin_unlock_irq(&dev->power.lock);
744 pm_runtime_put(parent);
746 spin_lock_irq(&dev->power.lock);
749 trace_rpm_return_int(dev, _THIS_IP_, retval);
755 * pm_runtime_work - Universal runtime PM work function.
756 * @work: Work structure used for scheduling the execution of this function.
758 * Use @work to get the device object the work is to be done for, determine what
759 * is to be done and execute the appropriate runtime PM function.
761 static void pm_runtime_work(struct work_struct *work)
763 struct device *dev = container_of(work, struct device, power.work);
764 enum rpm_request req;
766 spin_lock_irq(&dev->power.lock);
768 if (!dev->power.request_pending)
771 req = dev->power.request;
772 dev->power.request = RPM_REQ_NONE;
773 dev->power.request_pending = false;
779 rpm_idle(dev, RPM_NOWAIT);
781 case RPM_REQ_SUSPEND:
782 rpm_suspend(dev, RPM_NOWAIT);
784 case RPM_REQ_AUTOSUSPEND:
785 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
788 rpm_resume(dev, RPM_NOWAIT);
793 spin_unlock_irq(&dev->power.lock);
797 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
798 * @data: Device pointer passed by pm_schedule_suspend().
800 * Check if the time is right and queue a suspend request.
802 static void pm_suspend_timer_fn(unsigned long data)
804 struct device *dev = (struct device *)data;
806 unsigned long expires;
808 spin_lock_irqsave(&dev->power.lock, flags);
810 expires = dev->power.timer_expires;
811 /* If 'expire' is after 'jiffies' we've been called too early. */
812 if (expires > 0 && !time_after(expires, jiffies)) {
813 dev->power.timer_expires = 0;
814 rpm_suspend(dev, dev->power.timer_autosuspends ?
815 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
818 spin_unlock_irqrestore(&dev->power.lock, flags);
822 * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
823 * @dev: Device to suspend.
824 * @delay: Time to wait before submitting a suspend request, in milliseconds.
826 int pm_schedule_suspend(struct device *dev, unsigned int delay)
831 spin_lock_irqsave(&dev->power.lock, flags);
834 retval = rpm_suspend(dev, RPM_ASYNC);
838 retval = rpm_check_suspend_allowed(dev);
842 /* Other scheduled or pending requests need to be canceled. */
843 pm_runtime_cancel_pending(dev);
845 dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
846 dev->power.timer_expires += !dev->power.timer_expires;
847 dev->power.timer_autosuspends = 0;
848 mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
851 spin_unlock_irqrestore(&dev->power.lock, flags);
855 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
858 * __pm_runtime_idle - Entry point for runtime idle operations.
859 * @dev: Device to send idle notification for.
860 * @rpmflags: Flag bits.
862 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
863 * return immediately if it is larger than zero. Then carry out an idle
864 * notification, either synchronous or asynchronous.
866 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
867 * or if pm_runtime_irq_safe() has been called.
869 int __pm_runtime_idle(struct device *dev, int rpmflags)
874 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
876 if (rpmflags & RPM_GET_PUT) {
877 if (!atomic_dec_and_test(&dev->power.usage_count))
881 spin_lock_irqsave(&dev->power.lock, flags);
882 retval = rpm_idle(dev, rpmflags);
883 spin_unlock_irqrestore(&dev->power.lock, flags);
887 EXPORT_SYMBOL_GPL(__pm_runtime_idle);
890 * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
891 * @dev: Device to suspend.
892 * @rpmflags: Flag bits.
894 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
895 * return immediately if it is larger than zero. Then carry out a suspend,
896 * either synchronous or asynchronous.
898 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
899 * or if pm_runtime_irq_safe() has been called.
901 int __pm_runtime_suspend(struct device *dev, int rpmflags)
906 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
908 if (rpmflags & RPM_GET_PUT) {
909 if (!atomic_dec_and_test(&dev->power.usage_count))
913 spin_lock_irqsave(&dev->power.lock, flags);
914 retval = rpm_suspend(dev, rpmflags);
915 spin_unlock_irqrestore(&dev->power.lock, flags);
919 EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
922 * __pm_runtime_resume - Entry point for runtime resume operations.
923 * @dev: Device to resume.
924 * @rpmflags: Flag bits.
926 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
927 * carry out a resume, either synchronous or asynchronous.
929 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
930 * or if pm_runtime_irq_safe() has been called.
932 int __pm_runtime_resume(struct device *dev, int rpmflags)
937 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
939 if (rpmflags & RPM_GET_PUT)
940 atomic_inc(&dev->power.usage_count);
942 spin_lock_irqsave(&dev->power.lock, flags);
943 retval = rpm_resume(dev, rpmflags);
944 spin_unlock_irqrestore(&dev->power.lock, flags);
948 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
951 * __pm_runtime_set_status - Set runtime PM status of a device.
952 * @dev: Device to handle.
953 * @status: New runtime PM status of the device.
955 * If runtime PM of the device is disabled or its power.runtime_error field is
956 * different from zero, the status may be changed either to RPM_ACTIVE, or to
957 * RPM_SUSPENDED, as long as that reflects the actual state of the device.
958 * However, if the device has a parent and the parent is not active, and the
959 * parent's power.ignore_children flag is unset, the device's status cannot be
960 * set to RPM_ACTIVE, so -EBUSY is returned in that case.
962 * If successful, __pm_runtime_set_status() clears the power.runtime_error field
963 * and the device parent's counter of unsuspended children is modified to
964 * reflect the new status. If the new status is RPM_SUSPENDED, an idle
965 * notification request for the parent is submitted.
967 int __pm_runtime_set_status(struct device *dev, unsigned int status)
969 struct device *parent = dev->parent;
971 bool notify_parent = false;
974 if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
977 spin_lock_irqsave(&dev->power.lock, flags);
979 if (!dev->power.runtime_error && !dev->power.disable_depth) {
984 if (dev->power.runtime_status == status)
987 if (status == RPM_SUSPENDED) {
988 /* It always is possible to set the status to 'suspended'. */
990 atomic_add_unless(&parent->power.child_count, -1, 0);
991 notify_parent = !parent->power.ignore_children;
997 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
1000 * It is invalid to put an active child under a parent that is
1001 * not active, has runtime PM enabled and the
1002 * 'power.ignore_children' flag unset.
1004 if (!parent->power.disable_depth
1005 && !parent->power.ignore_children
1006 && parent->power.runtime_status != RPM_ACTIVE)
1008 else if (dev->power.runtime_status == RPM_SUSPENDED)
1009 atomic_inc(&parent->power.child_count);
1011 spin_unlock(&parent->power.lock);
1018 __update_runtime_status(dev, status);
1019 dev->power.runtime_error = 0;
1021 spin_unlock_irqrestore(&dev->power.lock, flags);
1024 pm_request_idle(parent);
1028 EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
1031 * __pm_runtime_barrier - Cancel pending requests and wait for completions.
1032 * @dev: Device to handle.
1034 * Flush all pending requests for the device from pm_wq and wait for all
1035 * runtime PM operations involving the device in progress to complete.
1037 * Should be called under dev->power.lock with interrupts disabled.
1039 static void __pm_runtime_barrier(struct device *dev)
1041 pm_runtime_deactivate_timer(dev);
1043 if (dev->power.request_pending) {
1044 dev->power.request = RPM_REQ_NONE;
1045 spin_unlock_irq(&dev->power.lock);
1047 cancel_work_sync(&dev->power.work);
1049 spin_lock_irq(&dev->power.lock);
1050 dev->power.request_pending = false;
1053 if (dev->power.runtime_status == RPM_SUSPENDING
1054 || dev->power.runtime_status == RPM_RESUMING
1055 || dev->power.idle_notification) {
1058 /* Suspend, wake-up or idle notification in progress. */
1060 prepare_to_wait(&dev->power.wait_queue, &wait,
1061 TASK_UNINTERRUPTIBLE);
1062 if (dev->power.runtime_status != RPM_SUSPENDING
1063 && dev->power.runtime_status != RPM_RESUMING
1064 && !dev->power.idle_notification)
1066 spin_unlock_irq(&dev->power.lock);
1070 spin_lock_irq(&dev->power.lock);
1072 finish_wait(&dev->power.wait_queue, &wait);
1077 * pm_runtime_barrier - Flush pending requests and wait for completions.
1078 * @dev: Device to handle.
1080 * Prevent the device from being suspended by incrementing its usage counter and
1081 * if there's a pending resume request for the device, wake the device up.
1082 * Next, make sure that all pending requests for the device have been flushed
1083 * from pm_wq and wait for all runtime PM operations involving the device in
1084 * progress to complete.
1087 * 1, if there was a resume request pending and the device had to be woken up,
1090 int pm_runtime_barrier(struct device *dev)
1094 pm_runtime_get_noresume(dev);
1095 spin_lock_irq(&dev->power.lock);
1097 if (dev->power.request_pending
1098 && dev->power.request == RPM_REQ_RESUME) {
1103 __pm_runtime_barrier(dev);
1105 spin_unlock_irq(&dev->power.lock);
1106 pm_runtime_put_noidle(dev);
1110 EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1113 * __pm_runtime_disable - Disable runtime PM of a device.
1114 * @dev: Device to handle.
1115 * @check_resume: If set, check if there's a resume request for the device.
1117 * Increment power.disable_depth for the device and if was zero previously,
1118 * cancel all pending runtime PM requests for the device and wait for all
1119 * operations in progress to complete. The device can be either active or
1120 * suspended after its runtime PM has been disabled.
1122 * If @check_resume is set and there's a resume request pending when
1123 * __pm_runtime_disable() is called and power.disable_depth is zero, the
1124 * function will wake up the device before disabling its runtime PM.
1126 void __pm_runtime_disable(struct device *dev, bool check_resume)
1128 spin_lock_irq(&dev->power.lock);
1130 if (dev->power.disable_depth > 0) {
1131 dev->power.disable_depth++;
1136 * Wake up the device if there's a resume request pending, because that
1137 * means there probably is some I/O to process and disabling runtime PM
1138 * shouldn't prevent the device from processing the I/O.
1140 if (check_resume && dev->power.request_pending
1141 && dev->power.request == RPM_REQ_RESUME) {
1143 * Prevent suspends and idle notifications from being carried
1144 * out after we have woken up the device.
1146 pm_runtime_get_noresume(dev);
1150 pm_runtime_put_noidle(dev);
1153 if (!dev->power.disable_depth++)
1154 __pm_runtime_barrier(dev);
1157 spin_unlock_irq(&dev->power.lock);
1159 EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1162 * pm_runtime_enable - Enable runtime PM of a device.
1163 * @dev: Device to handle.
1165 void pm_runtime_enable(struct device *dev)
1167 unsigned long flags;
1169 spin_lock_irqsave(&dev->power.lock, flags);
1171 if (dev->power.disable_depth > 0)
1172 dev->power.disable_depth--;
1174 dev_warn(dev, "Unbalanced %s!\n", __func__);
1176 spin_unlock_irqrestore(&dev->power.lock, flags);
1178 EXPORT_SYMBOL_GPL(pm_runtime_enable);
1181 * pm_runtime_forbid - Block runtime PM of a device.
1182 * @dev: Device to handle.
1184 * Increase the device's usage count and clear its power.runtime_auto flag,
1185 * so that it cannot be suspended at run time until pm_runtime_allow() is called
1188 void pm_runtime_forbid(struct device *dev)
1190 spin_lock_irq(&dev->power.lock);
1191 if (!dev->power.runtime_auto)
1194 dev->power.runtime_auto = false;
1195 atomic_inc(&dev->power.usage_count);
1199 spin_unlock_irq(&dev->power.lock);
1201 EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1204 * pm_runtime_allow - Unblock runtime PM of a device.
1205 * @dev: Device to handle.
1207 * Decrease the device's usage count and set its power.runtime_auto flag.
1209 void pm_runtime_allow(struct device *dev)
1211 spin_lock_irq(&dev->power.lock);
1212 if (dev->power.runtime_auto)
1215 dev->power.runtime_auto = true;
1216 if (atomic_dec_and_test(&dev->power.usage_count))
1217 rpm_idle(dev, RPM_AUTO);
1220 spin_unlock_irq(&dev->power.lock);
1222 EXPORT_SYMBOL_GPL(pm_runtime_allow);
1225 * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1226 * @dev: Device to handle.
1228 * Set the power.no_callbacks flag, which tells the PM core that this
1229 * device is power-managed through its parent and has no runtime PM
1230 * callbacks of its own. The runtime sysfs attributes will be removed.
1232 void pm_runtime_no_callbacks(struct device *dev)
1234 spin_lock_irq(&dev->power.lock);
1235 dev->power.no_callbacks = 1;
1236 spin_unlock_irq(&dev->power.lock);
1237 if (device_is_registered(dev))
1238 rpm_sysfs_remove(dev);
1240 EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1243 * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1244 * @dev: Device to handle
1246 * Set the power.irq_safe flag, which tells the PM core that the
1247 * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1248 * always be invoked with the spinlock held and interrupts disabled. It also
1249 * causes the parent's usage counter to be permanently incremented, preventing
1250 * the parent from runtime suspending -- otherwise an irq-safe child might have
1251 * to wait for a non-irq-safe parent.
1253 void pm_runtime_irq_safe(struct device *dev)
1256 pm_runtime_get_sync(dev->parent);
1257 spin_lock_irq(&dev->power.lock);
1258 dev->power.irq_safe = 1;
1259 spin_unlock_irq(&dev->power.lock);
1261 EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1264 * update_autosuspend - Handle a change to a device's autosuspend settings.
1265 * @dev: Device to handle.
1266 * @old_delay: The former autosuspend_delay value.
1267 * @old_use: The former use_autosuspend value.
1269 * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1270 * set; otherwise allow it. Send an idle notification if suspends are allowed.
1272 * This function must be called under dev->power.lock with interrupts disabled.
1274 static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1276 int delay = dev->power.autosuspend_delay;
1278 /* Should runtime suspend be prevented now? */
1279 if (dev->power.use_autosuspend && delay < 0) {
1281 /* If it used to be allowed then prevent it. */
1282 if (!old_use || old_delay >= 0) {
1283 atomic_inc(&dev->power.usage_count);
1288 /* Runtime suspend should be allowed now. */
1291 /* If it used to be prevented then allow it. */
1292 if (old_use && old_delay < 0)
1293 atomic_dec(&dev->power.usage_count);
1295 /* Maybe we can autosuspend now. */
1296 rpm_idle(dev, RPM_AUTO);
1301 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1302 * @dev: Device to handle.
1303 * @delay: Value of the new delay in milliseconds.
1305 * Set the device's power.autosuspend_delay value. If it changes to negative
1306 * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1307 * changes the other way, allow runtime suspends.
1309 void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1311 int old_delay, old_use;
1313 spin_lock_irq(&dev->power.lock);
1314 old_delay = dev->power.autosuspend_delay;
1315 old_use = dev->power.use_autosuspend;
1316 dev->power.autosuspend_delay = delay;
1317 update_autosuspend(dev, old_delay, old_use);
1318 spin_unlock_irq(&dev->power.lock);
1320 EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1323 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1324 * @dev: Device to handle.
1325 * @use: New value for use_autosuspend.
1327 * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1328 * suspends as needed.
1330 void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1332 int old_delay, old_use;
1334 spin_lock_irq(&dev->power.lock);
1335 old_delay = dev->power.autosuspend_delay;
1336 old_use = dev->power.use_autosuspend;
1337 dev->power.use_autosuspend = use;
1338 update_autosuspend(dev, old_delay, old_use);
1339 spin_unlock_irq(&dev->power.lock);
1341 EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1344 * pm_runtime_init - Initialize runtime PM fields in given device object.
1345 * @dev: Device object to initialize.
1347 void pm_runtime_init(struct device *dev)
1349 dev->power.runtime_status = RPM_SUSPENDED;
1350 dev->power.idle_notification = false;
1352 dev->power.disable_depth = 1;
1353 atomic_set(&dev->power.usage_count, 0);
1355 dev->power.runtime_error = 0;
1357 atomic_set(&dev->power.child_count, 0);
1358 pm_suspend_ignore_children(dev, false);
1359 dev->power.runtime_auto = true;
1361 dev->power.request_pending = false;
1362 dev->power.request = RPM_REQ_NONE;
1363 dev->power.deferred_resume = false;
1364 dev->power.accounting_timestamp = jiffies;
1365 INIT_WORK(&dev->power.work, pm_runtime_work);
1367 dev->power.timer_expires = 0;
1368 setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
1369 (unsigned long)dev);
1371 init_waitqueue_head(&dev->power.wait_queue);
1375 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1376 * @dev: Device object being removed from device hierarchy.
1378 void pm_runtime_remove(struct device *dev)
1380 __pm_runtime_disable(dev, false);
1382 /* Change the status back to 'suspended' to match the initial status. */
1383 if (dev->power.runtime_status == RPM_ACTIVE)
1384 pm_runtime_set_suspended(dev);
1385 if (dev->power.irq_safe && dev->parent)
1386 pm_runtime_put_sync(dev->parent);