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
);