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
);