Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * drivers/base/power/runtime.c - Helper functions for device runtime PM
4 : *
5 : * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 : * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
7 : */
8 : #include <linux/sched/mm.h>
9 : #include <linux/ktime.h>
10 : #include <linux/hrtimer.h>
11 : #include <linux/export.h>
12 : #include <linux/pm_runtime.h>
13 : #include <linux/pm_wakeirq.h>
14 : #include <trace/events/rpm.h>
15 :
16 : #include "../base.h"
17 : #include "power.h"
18 :
19 : typedef int (*pm_callback_t)(struct device *);
20 :
21 0 : static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset)
22 : {
23 : pm_callback_t cb;
24 : const struct dev_pm_ops *ops;
25 :
26 0 : if (dev->pm_domain)
27 0 : ops = &dev->pm_domain->ops;
28 0 : else if (dev->type && dev->type->pm)
29 : ops = dev->type->pm;
30 0 : else if (dev->class && dev->class->pm)
31 : ops = dev->class->pm;
32 0 : else if (dev->bus && dev->bus->pm)
33 0 : ops = dev->bus->pm;
34 : else
35 : ops = NULL;
36 :
37 0 : if (ops)
38 0 : cb = *(pm_callback_t *)((void *)ops + cb_offset);
39 : else
40 : cb = NULL;
41 :
42 0 : if (!cb && dev->driver && dev->driver->pm)
43 0 : cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset);
44 :
45 0 : return cb;
46 : }
47 :
48 : #define RPM_GET_CALLBACK(dev, callback) \
49 : __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback))
50 :
51 : static int rpm_resume(struct device *dev, int rpmflags);
52 : static int rpm_suspend(struct device *dev, int rpmflags);
53 :
54 : /**
55 : * update_pm_runtime_accounting - Update the time accounting of power states
56 : * @dev: Device to update the accounting for
57 : *
58 : * In order to be able to have time accounting of the various power states
59 : * (as used by programs such as PowerTOP to show the effectiveness of runtime
60 : * PM), we need to track the time spent in each state.
61 : * update_pm_runtime_accounting must be called each time before the
62 : * runtime_status field is updated, to account the time in the old state
63 : * correctly.
64 : */
65 0 : static void update_pm_runtime_accounting(struct device *dev)
66 : {
67 : u64 now, last, delta;
68 :
69 0 : if (dev->power.disable_depth > 0)
70 : return;
71 :
72 0 : last = dev->power.accounting_timestamp;
73 :
74 0 : now = ktime_get_mono_fast_ns();
75 0 : dev->power.accounting_timestamp = now;
76 :
77 : /*
78 : * Because ktime_get_mono_fast_ns() is not monotonic during
79 : * timekeeping updates, ensure that 'now' is after the last saved
80 : * timesptamp.
81 : */
82 0 : if (now < last)
83 : return;
84 :
85 0 : delta = now - last;
86 :
87 0 : if (dev->power.runtime_status == RPM_SUSPENDED)
88 0 : dev->power.suspended_time += delta;
89 : else
90 0 : dev->power.active_time += delta;
91 : }
92 :
93 : static void __update_runtime_status(struct device *dev, enum rpm_status status)
94 : {
95 0 : update_pm_runtime_accounting(dev);
96 0 : dev->power.runtime_status = status;
97 : }
98 :
99 0 : static u64 rpm_get_accounted_time(struct device *dev, bool suspended)
100 : {
101 : u64 time;
102 : unsigned long flags;
103 :
104 0 : spin_lock_irqsave(&dev->power.lock, flags);
105 :
106 0 : update_pm_runtime_accounting(dev);
107 0 : time = suspended ? dev->power.suspended_time : dev->power.active_time;
108 :
109 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
110 :
111 0 : return time;
112 : }
113 :
114 0 : u64 pm_runtime_active_time(struct device *dev)
115 : {
116 0 : return rpm_get_accounted_time(dev, false);
117 : }
118 :
119 0 : u64 pm_runtime_suspended_time(struct device *dev)
120 : {
121 0 : return rpm_get_accounted_time(dev, true);
122 : }
123 : EXPORT_SYMBOL_GPL(pm_runtime_suspended_time);
124 :
125 : /**
126 : * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
127 : * @dev: Device to handle.
128 : */
129 : static void pm_runtime_deactivate_timer(struct device *dev)
130 : {
131 536 : if (dev->power.timer_expires > 0) {
132 0 : hrtimer_try_to_cancel(&dev->power.suspend_timer);
133 0 : dev->power.timer_expires = 0;
134 : }
135 : }
136 :
137 : /**
138 : * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
139 : * @dev: Device to handle.
140 : */
141 : static void pm_runtime_cancel_pending(struct device *dev)
142 : {
143 0 : pm_runtime_deactivate_timer(dev);
144 : /*
145 : * In case there's a request pending, make sure its work function will
146 : * return without doing anything.
147 : */
148 0 : dev->power.request = RPM_REQ_NONE;
149 : }
150 :
151 : /*
152 : * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
153 : * @dev: Device to handle.
154 : *
155 : * Compute the autosuspend-delay expiration time based on the device's
156 : * power.last_busy time. If the delay has already expired or is disabled
157 : * (negative) or the power.use_autosuspend flag isn't set, return 0.
158 : * Otherwise return the expiration time in nanoseconds (adjusted to be nonzero).
159 : *
160 : * This function may be called either with or without dev->power.lock held.
161 : * Either way it can be racy, since power.last_busy may be updated at any time.
162 : */
163 0 : u64 pm_runtime_autosuspend_expiration(struct device *dev)
164 : {
165 : int autosuspend_delay;
166 : u64 expires;
167 :
168 0 : if (!dev->power.use_autosuspend)
169 : return 0;
170 :
171 0 : autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
172 0 : if (autosuspend_delay < 0)
173 : return 0;
174 :
175 0 : expires = READ_ONCE(dev->power.last_busy);
176 0 : expires += (u64)autosuspend_delay * NSEC_PER_MSEC;
177 0 : if (expires > ktime_get_mono_fast_ns())
178 : return expires; /* Expires in the future */
179 :
180 0 : return 0;
181 : }
182 : EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
183 :
184 0 : static int dev_memalloc_noio(struct device *dev, void *data)
185 : {
186 0 : return dev->power.memalloc_noio;
187 : }
188 :
189 : /*
190 : * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
191 : * @dev: Device to handle.
192 : * @enable: True for setting the flag and False for clearing the flag.
193 : *
194 : * Set the flag for all devices in the path from the device to the
195 : * root device in the device tree if @enable is true, otherwise clear
196 : * the flag for devices in the path whose siblings don't set the flag.
197 : *
198 : * The function should only be called by block device, or network
199 : * device driver for solving the deadlock problem during runtime
200 : * resume/suspend:
201 : *
202 : * If memory allocation with GFP_KERNEL is called inside runtime
203 : * resume/suspend callback of any one of its ancestors(or the
204 : * block device itself), the deadlock may be triggered inside the
205 : * memory allocation since it might not complete until the block
206 : * device becomes active and the involed page I/O finishes. The
207 : * situation is pointed out first by Alan Stern. Network device
208 : * are involved in iSCSI kind of situation.
209 : *
210 : * The lock of dev_hotplug_mutex is held in the function for handling
211 : * hotplug race because pm_runtime_set_memalloc_noio() may be called
212 : * in async probe().
213 : *
214 : * The function should be called between device_add() and device_del()
215 : * on the affected device(block/network device).
216 : */
217 0 : void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
218 : {
219 : static DEFINE_MUTEX(dev_hotplug_mutex);
220 :
221 0 : mutex_lock(&dev_hotplug_mutex);
222 : for (;;) {
223 : bool enabled;
224 :
225 : /* hold power lock since bitfield is not SMP-safe. */
226 0 : spin_lock_irq(&dev->power.lock);
227 0 : enabled = dev->power.memalloc_noio;
228 0 : dev->power.memalloc_noio = enable;
229 0 : spin_unlock_irq(&dev->power.lock);
230 :
231 : /*
232 : * not need to enable ancestors any more if the device
233 : * has been enabled.
234 : */
235 0 : if (enabled && enable)
236 : break;
237 :
238 0 : dev = dev->parent;
239 :
240 : /*
241 : * clear flag of the parent device only if all the
242 : * children don't set the flag because ancestor's
243 : * flag was set by any one of the descendants.
244 : */
245 0 : if (!dev || (!enable &&
246 0 : device_for_each_child(dev, NULL,
247 : dev_memalloc_noio)))
248 : break;
249 : }
250 0 : mutex_unlock(&dev_hotplug_mutex);
251 0 : }
252 : EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
253 :
254 : /**
255 : * rpm_check_suspend_allowed - Test whether a device may be suspended.
256 : * @dev: Device to test.
257 : */
258 4 : static int rpm_check_suspend_allowed(struct device *dev)
259 : {
260 4 : int retval = 0;
261 :
262 4 : if (dev->power.runtime_error)
263 : retval = -EINVAL;
264 4 : else if (dev->power.disable_depth > 0)
265 : retval = -EACCES;
266 0 : else if (atomic_read(&dev->power.usage_count) > 0)
267 : retval = -EAGAIN;
268 0 : else if (!dev->power.ignore_children &&
269 0 : atomic_read(&dev->power.child_count))
270 : retval = -EBUSY;
271 :
272 : /* Pending resume requests take precedence over suspends. */
273 0 : else if ((dev->power.deferred_resume
274 0 : && dev->power.runtime_status == RPM_SUSPENDING)
275 0 : || (dev->power.request_pending
276 0 : && dev->power.request == RPM_REQ_RESUME))
277 : retval = -EAGAIN;
278 0 : else if (__dev_pm_qos_resume_latency(dev) == 0)
279 : retval = -EPERM;
280 0 : else if (dev->power.runtime_status == RPM_SUSPENDED)
281 0 : retval = 1;
282 :
283 4 : return retval;
284 : }
285 :
286 0 : static int rpm_get_suppliers(struct device *dev)
287 : {
288 : struct device_link *link;
289 :
290 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
291 : device_links_read_lock_held()) {
292 : int retval;
293 :
294 0 : if (!(link->flags & DL_FLAG_PM_RUNTIME))
295 0 : continue;
296 :
297 0 : retval = pm_runtime_get_sync(link->supplier);
298 : /* Ignore suppliers with disabled runtime PM. */
299 0 : if (retval < 0 && retval != -EACCES) {
300 0 : pm_runtime_put_noidle(link->supplier);
301 : return retval;
302 : }
303 0 : refcount_inc(&link->rpm_active);
304 : }
305 : return 0;
306 : }
307 :
308 : /**
309 : * pm_runtime_release_supplier - Drop references to device link's supplier.
310 : * @link: Target device link.
311 : * @check_idle: Whether or not to check if the supplier device is idle.
312 : *
313 : * Drop all runtime PM references associated with @link to its supplier device
314 : * and if @check_idle is set, check if that device is idle (and so it can be
315 : * suspended).
316 : */
317 0 : void pm_runtime_release_supplier(struct device_link *link, bool check_idle)
318 : {
319 0 : struct device *supplier = link->supplier;
320 :
321 : /*
322 : * The additional power.usage_count check is a safety net in case
323 : * the rpm_active refcount becomes saturated, in which case
324 : * refcount_dec_not_one() would return true forever, but it is not
325 : * strictly necessary.
326 : */
327 0 : while (refcount_dec_not_one(&link->rpm_active) &&
328 0 : atomic_read(&supplier->power.usage_count) > 0)
329 : pm_runtime_put_noidle(supplier);
330 :
331 0 : if (check_idle)
332 : pm_request_idle(supplier);
333 0 : }
334 :
335 0 : static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
336 : {
337 : struct device_link *link;
338 :
339 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
340 : device_links_read_lock_held())
341 0 : pm_runtime_release_supplier(link, try_to_suspend);
342 0 : }
343 :
344 0 : static void rpm_put_suppliers(struct device *dev)
345 : {
346 0 : __rpm_put_suppliers(dev, true);
347 0 : }
348 :
349 0 : static void rpm_suspend_suppliers(struct device *dev)
350 : {
351 : struct device_link *link;
352 0 : int idx = device_links_read_lock();
353 :
354 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
355 : device_links_read_lock_held())
356 0 : pm_request_idle(link->supplier);
357 :
358 0 : device_links_read_unlock(idx);
359 0 : }
360 :
361 : /**
362 : * __rpm_callback - Run a given runtime PM callback for a given device.
363 : * @cb: Runtime PM callback to run.
364 : * @dev: Device to run the callback for.
365 : */
366 0 : static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
367 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
368 : {
369 0 : int retval = 0, idx;
370 0 : bool use_links = dev->power.links_count > 0;
371 :
372 0 : if (dev->power.irq_safe) {
373 0 : spin_unlock(&dev->power.lock);
374 : } else {
375 0 : spin_unlock_irq(&dev->power.lock);
376 :
377 : /*
378 : * Resume suppliers if necessary.
379 : *
380 : * The device's runtime PM status cannot change until this
381 : * routine returns, so it is safe to read the status outside of
382 : * the lock.
383 : */
384 0 : if (use_links && dev->power.runtime_status == RPM_RESUMING) {
385 0 : idx = device_links_read_lock();
386 :
387 0 : retval = rpm_get_suppliers(dev);
388 0 : if (retval) {
389 0 : rpm_put_suppliers(dev);
390 0 : goto fail;
391 : }
392 :
393 0 : device_links_read_unlock(idx);
394 : }
395 : }
396 :
397 0 : if (cb)
398 0 : retval = cb(dev);
399 :
400 0 : if (dev->power.irq_safe) {
401 0 : spin_lock(&dev->power.lock);
402 : } else {
403 : /*
404 : * If the device is suspending and the callback has returned
405 : * success, drop the usage counters of the suppliers that have
406 : * been reference counted on its resume.
407 : *
408 : * Do that if resume fails too.
409 : */
410 0 : if (use_links
411 0 : && ((dev->power.runtime_status == RPM_SUSPENDING && !retval)
412 0 : || (dev->power.runtime_status == RPM_RESUMING && retval))) {
413 0 : idx = device_links_read_lock();
414 :
415 0 : __rpm_put_suppliers(dev, false);
416 :
417 : fail:
418 0 : device_links_read_unlock(idx);
419 : }
420 :
421 0 : spin_lock_irq(&dev->power.lock);
422 : }
423 :
424 0 : return retval;
425 : }
426 :
427 : /**
428 : * rpm_idle - Notify device bus type if the device can be suspended.
429 : * @dev: Device to notify the bus type about.
430 : * @rpmflags: Flag bits.
431 : *
432 : * Check if the device's runtime PM status allows it to be suspended. If
433 : * another idle notification has been started earlier, return immediately. If
434 : * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
435 : * run the ->runtime_idle() callback directly. If the ->runtime_idle callback
436 : * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
437 : *
438 : * This function must be called under dev->power.lock with interrupts disabled.
439 : */
440 4 : static int rpm_idle(struct device *dev, int rpmflags)
441 : {
442 : int (*callback)(struct device *);
443 : int retval;
444 :
445 4 : trace_rpm_idle_rcuidle(dev, rpmflags);
446 4 : retval = rpm_check_suspend_allowed(dev);
447 4 : if (retval < 0)
448 : ; /* Conditions are wrong. */
449 :
450 : /* Idle notifications are allowed only in the RPM_ACTIVE state. */
451 0 : else if (dev->power.runtime_status != RPM_ACTIVE)
452 : retval = -EAGAIN;
453 :
454 : /*
455 : * Any pending request other than an idle notification takes
456 : * precedence over us, except that the timer may be running.
457 : */
458 0 : else if (dev->power.request_pending &&
459 0 : dev->power.request > RPM_REQ_IDLE)
460 : retval = -EAGAIN;
461 :
462 : /* Act as though RPM_NOWAIT is always set. */
463 0 : else if (dev->power.idle_notification)
464 0 : retval = -EINPROGRESS;
465 4 : if (retval)
466 : goto out;
467 :
468 : /* Pending requests need to be canceled. */
469 0 : dev->power.request = RPM_REQ_NONE;
470 :
471 0 : callback = RPM_GET_CALLBACK(dev, runtime_idle);
472 :
473 : /* If no callback assume success. */
474 0 : if (!callback || dev->power.no_callbacks)
475 : goto out;
476 :
477 : /* Carry out an asynchronous or a synchronous idle notification. */
478 0 : if (rpmflags & RPM_ASYNC) {
479 0 : dev->power.request = RPM_REQ_IDLE;
480 0 : if (!dev->power.request_pending) {
481 0 : dev->power.request_pending = true;
482 0 : queue_work(pm_wq, &dev->power.work);
483 : }
484 0 : trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
485 0 : return 0;
486 : }
487 :
488 0 : dev->power.idle_notification = true;
489 :
490 0 : retval = __rpm_callback(callback, dev);
491 :
492 0 : dev->power.idle_notification = false;
493 0 : wake_up_all(&dev->power.wait_queue);
494 :
495 : out:
496 4 : trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
497 4 : return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
498 : }
499 :
500 : /**
501 : * rpm_callback - Run a given runtime PM callback for a given device.
502 : * @cb: Runtime PM callback to run.
503 : * @dev: Device to run the callback for.
504 : */
505 0 : static int rpm_callback(int (*cb)(struct device *), struct device *dev)
506 : {
507 : int retval;
508 :
509 0 : if (dev->power.memalloc_noio) {
510 : unsigned int noio_flag;
511 :
512 : /*
513 : * Deadlock might be caused if memory allocation with
514 : * GFP_KERNEL happens inside runtime_suspend and
515 : * runtime_resume callbacks of one block device's
516 : * ancestor or the block device itself. Network
517 : * device might be thought as part of iSCSI block
518 : * device, so network device and its ancestor should
519 : * be marked as memalloc_noio too.
520 : */
521 0 : noio_flag = memalloc_noio_save();
522 0 : retval = __rpm_callback(cb, dev);
523 : memalloc_noio_restore(noio_flag);
524 : } else {
525 0 : retval = __rpm_callback(cb, dev);
526 : }
527 :
528 0 : dev->power.runtime_error = retval;
529 0 : return retval != -EACCES ? retval : -EIO;
530 : }
531 :
532 : /**
533 : * rpm_suspend - Carry out runtime suspend of given device.
534 : * @dev: Device to suspend.
535 : * @rpmflags: Flag bits.
536 : *
537 : * Check if the device's runtime PM status allows it to be suspended.
538 : * Cancel a pending idle notification, autosuspend or suspend. If
539 : * another suspend has been started earlier, either return immediately
540 : * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
541 : * flags. If the RPM_ASYNC flag is set then queue a suspend request;
542 : * otherwise run the ->runtime_suspend() callback directly. When
543 : * ->runtime_suspend succeeded, if a deferred resume was requested while
544 : * the callback was running then carry it out, otherwise send an idle
545 : * notification for its parent (if the suspend succeeded and both
546 : * ignore_children of parent->power and irq_safe of dev->power are not set).
547 : * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
548 : * flag is set and the next autosuspend-delay expiration time is in the
549 : * future, schedule another autosuspend attempt.
550 : *
551 : * This function must be called under dev->power.lock with interrupts disabled.
552 : */
553 0 : static int rpm_suspend(struct device *dev, int rpmflags)
554 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
555 : {
556 : int (*callback)(struct device *);
557 0 : struct device *parent = NULL;
558 : int retval;
559 :
560 0 : trace_rpm_suspend_rcuidle(dev, rpmflags);
561 :
562 : repeat:
563 0 : retval = rpm_check_suspend_allowed(dev);
564 0 : if (retval < 0)
565 : goto out; /* Conditions are wrong. */
566 :
567 : /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
568 0 : if (dev->power.runtime_status == RPM_RESUMING && !(rpmflags & RPM_ASYNC))
569 0 : retval = -EAGAIN;
570 0 : if (retval)
571 : goto out;
572 :
573 : /* If the autosuspend_delay time hasn't expired yet, reschedule. */
574 0 : if ((rpmflags & RPM_AUTO)
575 0 : && dev->power.runtime_status != RPM_SUSPENDING) {
576 0 : u64 expires = pm_runtime_autosuspend_expiration(dev);
577 :
578 0 : if (expires != 0) {
579 : /* Pending requests need to be canceled. */
580 0 : dev->power.request = RPM_REQ_NONE;
581 :
582 : /*
583 : * Optimization: If the timer is already running and is
584 : * set to expire at or before the autosuspend delay,
585 : * avoid the overhead of resetting it. Just let it
586 : * expire; pm_suspend_timer_fn() will take care of the
587 : * rest.
588 : */
589 0 : if (!(dev->power.timer_expires &&
590 : dev->power.timer_expires <= expires)) {
591 : /*
592 : * We add a slack of 25% to gather wakeups
593 : * without sacrificing the granularity.
594 : */
595 0 : u64 slack = (u64)READ_ONCE(dev->power.autosuspend_delay) *
596 : (NSEC_PER_MSEC >> 2);
597 :
598 0 : dev->power.timer_expires = expires;
599 0 : hrtimer_start_range_ns(&dev->power.suspend_timer,
600 : ns_to_ktime(expires),
601 : slack,
602 : HRTIMER_MODE_ABS);
603 : }
604 0 : dev->power.timer_autosuspends = 1;
605 0 : goto out;
606 : }
607 : }
608 :
609 : /* Other scheduled or pending requests need to be canceled. */
610 0 : pm_runtime_cancel_pending(dev);
611 :
612 0 : if (dev->power.runtime_status == RPM_SUSPENDING) {
613 0 : DEFINE_WAIT(wait);
614 :
615 0 : if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
616 0 : retval = -EINPROGRESS;
617 0 : goto out;
618 : }
619 :
620 0 : if (dev->power.irq_safe) {
621 0 : spin_unlock(&dev->power.lock);
622 :
623 : cpu_relax();
624 :
625 0 : spin_lock(&dev->power.lock);
626 0 : goto repeat;
627 : }
628 :
629 : /* Wait for the other suspend running in parallel with us. */
630 : for (;;) {
631 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
632 : TASK_UNINTERRUPTIBLE);
633 0 : if (dev->power.runtime_status != RPM_SUSPENDING)
634 : break;
635 :
636 0 : spin_unlock_irq(&dev->power.lock);
637 :
638 0 : schedule();
639 :
640 0 : spin_lock_irq(&dev->power.lock);
641 : }
642 0 : finish_wait(&dev->power.wait_queue, &wait);
643 0 : goto repeat;
644 : }
645 :
646 0 : if (dev->power.no_callbacks)
647 : goto no_callback; /* Assume success. */
648 :
649 : /* Carry out an asynchronous or a synchronous suspend. */
650 0 : if (rpmflags & RPM_ASYNC) {
651 0 : dev->power.request = (rpmflags & RPM_AUTO) ?
652 0 : RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
653 0 : if (!dev->power.request_pending) {
654 0 : dev->power.request_pending = true;
655 0 : queue_work(pm_wq, &dev->power.work);
656 : }
657 : goto out;
658 : }
659 :
660 0 : __update_runtime_status(dev, RPM_SUSPENDING);
661 :
662 0 : callback = RPM_GET_CALLBACK(dev, runtime_suspend);
663 :
664 0 : dev_pm_enable_wake_irq_check(dev, true);
665 0 : retval = rpm_callback(callback, dev);
666 0 : if (retval)
667 : goto fail;
668 :
669 0 : dev_pm_enable_wake_irq_complete(dev);
670 :
671 : no_callback:
672 0 : __update_runtime_status(dev, RPM_SUSPENDED);
673 0 : pm_runtime_deactivate_timer(dev);
674 :
675 0 : if (dev->parent) {
676 0 : parent = dev->parent;
677 0 : atomic_add_unless(&parent->power.child_count, -1, 0);
678 : }
679 0 : wake_up_all(&dev->power.wait_queue);
680 :
681 0 : if (dev->power.deferred_resume) {
682 0 : dev->power.deferred_resume = false;
683 0 : rpm_resume(dev, 0);
684 0 : retval = -EAGAIN;
685 0 : goto out;
686 : }
687 :
688 0 : if (dev->power.irq_safe)
689 : goto out;
690 :
691 : /* Maybe the parent is now able to suspend. */
692 0 : if (parent && !parent->power.ignore_children) {
693 0 : spin_unlock(&dev->power.lock);
694 :
695 0 : spin_lock(&parent->power.lock);
696 0 : rpm_idle(parent, RPM_ASYNC);
697 0 : spin_unlock(&parent->power.lock);
698 :
699 0 : spin_lock(&dev->power.lock);
700 : }
701 : /* Maybe the suppliers are now able to suspend. */
702 0 : if (dev->power.links_count > 0) {
703 0 : spin_unlock_irq(&dev->power.lock);
704 :
705 0 : rpm_suspend_suppliers(dev);
706 :
707 0 : spin_lock_irq(&dev->power.lock);
708 : }
709 :
710 : out:
711 0 : trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
712 :
713 0 : return retval;
714 :
715 : fail:
716 0 : dev_pm_disable_wake_irq_check(dev, true);
717 0 : __update_runtime_status(dev, RPM_ACTIVE);
718 0 : dev->power.deferred_resume = false;
719 0 : wake_up_all(&dev->power.wait_queue);
720 :
721 0 : if (retval == -EAGAIN || retval == -EBUSY) {
722 0 : dev->power.runtime_error = 0;
723 :
724 : /*
725 : * If the callback routine failed an autosuspend, and
726 : * if the last_busy time has been updated so that there
727 : * is a new autosuspend expiration time, automatically
728 : * reschedule another autosuspend.
729 : */
730 0 : if ((rpmflags & RPM_AUTO) &&
731 0 : pm_runtime_autosuspend_expiration(dev) != 0)
732 : goto repeat;
733 : } else {
734 : pm_runtime_cancel_pending(dev);
735 : }
736 : goto out;
737 : }
738 :
739 : /**
740 : * rpm_resume - Carry out runtime resume of given device.
741 : * @dev: Device to resume.
742 : * @rpmflags: Flag bits.
743 : *
744 : * Check if the device's runtime PM status allows it to be resumed. Cancel
745 : * any scheduled or pending requests. If another resume has been started
746 : * earlier, either return immediately or wait for it to finish, depending on the
747 : * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
748 : * parallel with this function, either tell the other process to resume after
749 : * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
750 : * flag is set then queue a resume request; otherwise run the
751 : * ->runtime_resume() callback directly. Queue an idle notification for the
752 : * device if the resume succeeded.
753 : *
754 : * This function must be called under dev->power.lock with interrupts disabled.
755 : */
756 0 : static int rpm_resume(struct device *dev, int rpmflags)
757 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
758 : {
759 : int (*callback)(struct device *);
760 0 : struct device *parent = NULL;
761 0 : int retval = 0;
762 :
763 0 : trace_rpm_resume_rcuidle(dev, rpmflags);
764 :
765 : repeat:
766 0 : if (dev->power.runtime_error) {
767 : retval = -EINVAL;
768 0 : } else if (dev->power.disable_depth > 0) {
769 0 : if (dev->power.runtime_status == RPM_ACTIVE &&
770 0 : dev->power.last_status == RPM_ACTIVE)
771 : retval = 1;
772 : else
773 0 : retval = -EACCES;
774 : }
775 0 : if (retval)
776 : goto out;
777 :
778 : /*
779 : * Other scheduled or pending requests need to be canceled. Small
780 : * optimization: If an autosuspend timer is running, leave it running
781 : * rather than cancelling it now only to restart it again in the near
782 : * future.
783 : */
784 0 : dev->power.request = RPM_REQ_NONE;
785 0 : if (!dev->power.timer_autosuspends)
786 : pm_runtime_deactivate_timer(dev);
787 :
788 0 : if (dev->power.runtime_status == RPM_ACTIVE) {
789 : retval = 1;
790 : goto out;
791 : }
792 :
793 0 : if (dev->power.runtime_status == RPM_RESUMING
794 0 : || dev->power.runtime_status == RPM_SUSPENDING) {
795 0 : DEFINE_WAIT(wait);
796 :
797 0 : if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
798 0 : if (dev->power.runtime_status == RPM_SUSPENDING)
799 0 : dev->power.deferred_resume = true;
800 : else
801 : retval = -EINPROGRESS;
802 0 : goto out;
803 : }
804 :
805 0 : if (dev->power.irq_safe) {
806 0 : spin_unlock(&dev->power.lock);
807 :
808 : cpu_relax();
809 :
810 0 : spin_lock(&dev->power.lock);
811 0 : goto repeat;
812 : }
813 :
814 : /* Wait for the operation carried out in parallel with us. */
815 : for (;;) {
816 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
817 : TASK_UNINTERRUPTIBLE);
818 0 : if (dev->power.runtime_status != RPM_RESUMING
819 0 : && dev->power.runtime_status != RPM_SUSPENDING)
820 : break;
821 :
822 0 : spin_unlock_irq(&dev->power.lock);
823 :
824 0 : schedule();
825 :
826 0 : spin_lock_irq(&dev->power.lock);
827 : }
828 0 : finish_wait(&dev->power.wait_queue, &wait);
829 0 : goto repeat;
830 : }
831 :
832 : /*
833 : * See if we can skip waking up the parent. This is safe only if
834 : * power.no_callbacks is set, because otherwise we don't know whether
835 : * the resume will actually succeed.
836 : */
837 0 : if (dev->power.no_callbacks && !parent && dev->parent) {
838 0 : spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
839 0 : if (dev->parent->power.disable_depth > 0
840 0 : || dev->parent->power.ignore_children
841 0 : || dev->parent->power.runtime_status == RPM_ACTIVE) {
842 0 : atomic_inc(&dev->parent->power.child_count);
843 0 : spin_unlock(&dev->parent->power.lock);
844 0 : retval = 1;
845 0 : goto no_callback; /* Assume success. */
846 : }
847 0 : spin_unlock(&dev->parent->power.lock);
848 : }
849 :
850 : /* Carry out an asynchronous or a synchronous resume. */
851 0 : if (rpmflags & RPM_ASYNC) {
852 0 : dev->power.request = RPM_REQ_RESUME;
853 0 : if (!dev->power.request_pending) {
854 0 : dev->power.request_pending = true;
855 0 : queue_work(pm_wq, &dev->power.work);
856 : }
857 : retval = 0;
858 : goto out;
859 : }
860 :
861 0 : if (!parent && dev->parent) {
862 : /*
863 : * Increment the parent's usage counter and resume it if
864 : * necessary. Not needed if dev is irq-safe; then the
865 : * parent is permanently resumed.
866 : */
867 0 : parent = dev->parent;
868 0 : if (dev->power.irq_safe)
869 : goto skip_parent;
870 0 : spin_unlock(&dev->power.lock);
871 :
872 0 : pm_runtime_get_noresume(parent);
873 :
874 0 : spin_lock(&parent->power.lock);
875 : /*
876 : * Resume the parent if it has runtime PM enabled and not been
877 : * set to ignore its children.
878 : */
879 0 : if (!parent->power.disable_depth
880 0 : && !parent->power.ignore_children) {
881 0 : rpm_resume(parent, 0);
882 0 : if (parent->power.runtime_status != RPM_ACTIVE)
883 0 : retval = -EBUSY;
884 : }
885 0 : spin_unlock(&parent->power.lock);
886 :
887 0 : spin_lock(&dev->power.lock);
888 0 : if (retval)
889 : goto out;
890 : goto repeat;
891 : }
892 : skip_parent:
893 :
894 0 : if (dev->power.no_callbacks)
895 : goto no_callback; /* Assume success. */
896 :
897 0 : __update_runtime_status(dev, RPM_RESUMING);
898 :
899 0 : callback = RPM_GET_CALLBACK(dev, runtime_resume);
900 :
901 0 : dev_pm_disable_wake_irq_check(dev, false);
902 0 : retval = rpm_callback(callback, dev);
903 0 : if (retval) {
904 0 : __update_runtime_status(dev, RPM_SUSPENDED);
905 0 : pm_runtime_cancel_pending(dev);
906 0 : dev_pm_enable_wake_irq_check(dev, false);
907 : } else {
908 : no_callback:
909 0 : __update_runtime_status(dev, RPM_ACTIVE);
910 0 : pm_runtime_mark_last_busy(dev);
911 0 : if (parent)
912 0 : atomic_inc(&parent->power.child_count);
913 : }
914 0 : wake_up_all(&dev->power.wait_queue);
915 :
916 0 : if (retval >= 0)
917 0 : rpm_idle(dev, RPM_ASYNC);
918 :
919 : out:
920 0 : if (parent && !dev->power.irq_safe) {
921 0 : spin_unlock_irq(&dev->power.lock);
922 :
923 0 : pm_runtime_put(parent);
924 :
925 0 : spin_lock_irq(&dev->power.lock);
926 : }
927 :
928 0 : trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
929 :
930 0 : return retval;
931 : }
932 :
933 : /**
934 : * pm_runtime_work - Universal runtime PM work function.
935 : * @work: Work structure used for scheduling the execution of this function.
936 : *
937 : * Use @work to get the device object the work is to be done for, determine what
938 : * is to be done and execute the appropriate runtime PM function.
939 : */
940 0 : static void pm_runtime_work(struct work_struct *work)
941 : {
942 0 : struct device *dev = container_of(work, struct device, power.work);
943 : enum rpm_request req;
944 :
945 0 : spin_lock_irq(&dev->power.lock);
946 :
947 0 : if (!dev->power.request_pending)
948 : goto out;
949 :
950 0 : req = dev->power.request;
951 0 : dev->power.request = RPM_REQ_NONE;
952 0 : dev->power.request_pending = false;
953 :
954 0 : switch (req) {
955 : case RPM_REQ_NONE:
956 : break;
957 : case RPM_REQ_IDLE:
958 0 : rpm_idle(dev, RPM_NOWAIT);
959 0 : break;
960 : case RPM_REQ_SUSPEND:
961 0 : rpm_suspend(dev, RPM_NOWAIT);
962 0 : break;
963 : case RPM_REQ_AUTOSUSPEND:
964 0 : rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
965 0 : break;
966 : case RPM_REQ_RESUME:
967 0 : rpm_resume(dev, RPM_NOWAIT);
968 0 : break;
969 : }
970 :
971 : out:
972 0 : spin_unlock_irq(&dev->power.lock);
973 0 : }
974 :
975 : /**
976 : * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
977 : * @timer: hrtimer used by pm_schedule_suspend().
978 : *
979 : * Check if the time is right and queue a suspend request.
980 : */
981 0 : static enum hrtimer_restart pm_suspend_timer_fn(struct hrtimer *timer)
982 : {
983 0 : struct device *dev = container_of(timer, struct device, power.suspend_timer);
984 : unsigned long flags;
985 : u64 expires;
986 :
987 0 : spin_lock_irqsave(&dev->power.lock, flags);
988 :
989 0 : expires = dev->power.timer_expires;
990 : /*
991 : * If 'expires' is after the current time, we've been called
992 : * too early.
993 : */
994 0 : if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
995 0 : dev->power.timer_expires = 0;
996 0 : rpm_suspend(dev, dev->power.timer_autosuspends ?
997 : (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
998 : }
999 :
1000 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1001 :
1002 0 : return HRTIMER_NORESTART;
1003 : }
1004 :
1005 : /**
1006 : * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
1007 : * @dev: Device to suspend.
1008 : * @delay: Time to wait before submitting a suspend request, in milliseconds.
1009 : */
1010 0 : int pm_schedule_suspend(struct device *dev, unsigned int delay)
1011 : {
1012 : unsigned long flags;
1013 : u64 expires;
1014 : int retval;
1015 :
1016 0 : spin_lock_irqsave(&dev->power.lock, flags);
1017 :
1018 0 : if (!delay) {
1019 0 : retval = rpm_suspend(dev, RPM_ASYNC);
1020 0 : goto out;
1021 : }
1022 :
1023 0 : retval = rpm_check_suspend_allowed(dev);
1024 0 : if (retval)
1025 : goto out;
1026 :
1027 : /* Other scheduled or pending requests need to be canceled. */
1028 0 : pm_runtime_cancel_pending(dev);
1029 :
1030 0 : expires = ktime_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC;
1031 0 : dev->power.timer_expires = expires;
1032 0 : dev->power.timer_autosuspends = 0;
1033 0 : hrtimer_start(&dev->power.suspend_timer, expires, HRTIMER_MODE_ABS);
1034 :
1035 : out:
1036 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1037 :
1038 0 : return retval;
1039 : }
1040 : EXPORT_SYMBOL_GPL(pm_schedule_suspend);
1041 :
1042 : /**
1043 : * __pm_runtime_idle - Entry point for runtime idle operations.
1044 : * @dev: Device to send idle notification for.
1045 : * @rpmflags: Flag bits.
1046 : *
1047 : * If the RPM_GET_PUT flag is set, decrement the device's usage count and
1048 : * return immediately if it is larger than zero. Then carry out an idle
1049 : * notification, either synchronous or asynchronous.
1050 : *
1051 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1052 : * or if pm_runtime_irq_safe() has been called.
1053 : */
1054 4 : int __pm_runtime_idle(struct device *dev, int rpmflags)
1055 : {
1056 : unsigned long flags;
1057 : int retval;
1058 :
1059 4 : if (rpmflags & RPM_GET_PUT) {
1060 0 : if (!atomic_dec_and_test(&dev->power.usage_count)) {
1061 : trace_rpm_usage_rcuidle(dev, rpmflags);
1062 : return 0;
1063 : }
1064 : }
1065 :
1066 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
1067 :
1068 4 : spin_lock_irqsave(&dev->power.lock, flags);
1069 4 : retval = rpm_idle(dev, rpmflags);
1070 8 : spin_unlock_irqrestore(&dev->power.lock, flags);
1071 :
1072 4 : return retval;
1073 : }
1074 : EXPORT_SYMBOL_GPL(__pm_runtime_idle);
1075 :
1076 : /**
1077 : * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
1078 : * @dev: Device to suspend.
1079 : * @rpmflags: Flag bits.
1080 : *
1081 : * If the RPM_GET_PUT flag is set, decrement the device's usage count and
1082 : * return immediately if it is larger than zero. Then carry out a suspend,
1083 : * either synchronous or asynchronous.
1084 : *
1085 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1086 : * or if pm_runtime_irq_safe() has been called.
1087 : */
1088 0 : int __pm_runtime_suspend(struct device *dev, int rpmflags)
1089 : {
1090 : unsigned long flags;
1091 : int retval;
1092 :
1093 0 : if (rpmflags & RPM_GET_PUT) {
1094 0 : if (!atomic_dec_and_test(&dev->power.usage_count)) {
1095 : trace_rpm_usage_rcuidle(dev, rpmflags);
1096 : return 0;
1097 : }
1098 : }
1099 :
1100 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
1101 :
1102 0 : spin_lock_irqsave(&dev->power.lock, flags);
1103 0 : retval = rpm_suspend(dev, rpmflags);
1104 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1105 :
1106 0 : return retval;
1107 : }
1108 : EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
1109 :
1110 : /**
1111 : * __pm_runtime_resume - Entry point for runtime resume operations.
1112 : * @dev: Device to resume.
1113 : * @rpmflags: Flag bits.
1114 : *
1115 : * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
1116 : * carry out a resume, either synchronous or asynchronous.
1117 : *
1118 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1119 : * or if pm_runtime_irq_safe() has been called.
1120 : */
1121 0 : int __pm_runtime_resume(struct device *dev, int rpmflags)
1122 : {
1123 : unsigned long flags;
1124 : int retval;
1125 :
1126 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
1127 : dev->power.runtime_status != RPM_ACTIVE);
1128 :
1129 0 : if (rpmflags & RPM_GET_PUT)
1130 0 : atomic_inc(&dev->power.usage_count);
1131 :
1132 0 : spin_lock_irqsave(&dev->power.lock, flags);
1133 0 : retval = rpm_resume(dev, rpmflags);
1134 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1135 :
1136 0 : return retval;
1137 : }
1138 : EXPORT_SYMBOL_GPL(__pm_runtime_resume);
1139 :
1140 : /**
1141 : * pm_runtime_get_if_active - Conditionally bump up device usage counter.
1142 : * @dev: Device to handle.
1143 : * @ign_usage_count: Whether or not to look at the current usage counter value.
1144 : *
1145 : * Return -EINVAL if runtime PM is disabled for @dev.
1146 : *
1147 : * Otherwise, if the runtime PM status of @dev is %RPM_ACTIVE and either
1148 : * @ign_usage_count is %true or the runtime PM usage counter of @dev is not
1149 : * zero, increment the usage counter of @dev and return 1. Otherwise, return 0
1150 : * without changing the usage counter.
1151 : *
1152 : * If @ign_usage_count is %true, this function can be used to prevent suspending
1153 : * the device when its runtime PM status is %RPM_ACTIVE.
1154 : *
1155 : * If @ign_usage_count is %false, this function can be used to prevent
1156 : * suspending the device when both its runtime PM status is %RPM_ACTIVE and its
1157 : * runtime PM usage counter is not zero.
1158 : *
1159 : * The caller is responsible for decrementing the runtime PM usage counter of
1160 : * @dev after this function has returned a positive value for it.
1161 : */
1162 0 : int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
1163 : {
1164 : unsigned long flags;
1165 : int retval;
1166 :
1167 0 : spin_lock_irqsave(&dev->power.lock, flags);
1168 0 : if (dev->power.disable_depth > 0) {
1169 : retval = -EINVAL;
1170 0 : } else if (dev->power.runtime_status != RPM_ACTIVE) {
1171 : retval = 0;
1172 0 : } else if (ign_usage_count) {
1173 0 : retval = 1;
1174 0 : atomic_inc(&dev->power.usage_count);
1175 : } else {
1176 0 : retval = atomic_inc_not_zero(&dev->power.usage_count);
1177 : }
1178 0 : trace_rpm_usage_rcuidle(dev, 0);
1179 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1180 :
1181 0 : return retval;
1182 : }
1183 : EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);
1184 :
1185 : /**
1186 : * __pm_runtime_set_status - Set runtime PM status of a device.
1187 : * @dev: Device to handle.
1188 : * @status: New runtime PM status of the device.
1189 : *
1190 : * If runtime PM of the device is disabled or its power.runtime_error field is
1191 : * different from zero, the status may be changed either to RPM_ACTIVE, or to
1192 : * RPM_SUSPENDED, as long as that reflects the actual state of the device.
1193 : * However, if the device has a parent and the parent is not active, and the
1194 : * parent's power.ignore_children flag is unset, the device's status cannot be
1195 : * set to RPM_ACTIVE, so -EBUSY is returned in that case.
1196 : *
1197 : * If successful, __pm_runtime_set_status() clears the power.runtime_error field
1198 : * and the device parent's counter of unsuspended children is modified to
1199 : * reflect the new status. If the new status is RPM_SUSPENDED, an idle
1200 : * notification request for the parent is submitted.
1201 : *
1202 : * If @dev has any suppliers (as reflected by device links to them), and @status
1203 : * is RPM_ACTIVE, they will be activated upfront and if the activation of one
1204 : * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead
1205 : * of the @status value) and the suppliers will be deacticated on exit. The
1206 : * error returned by the failing supplier activation will be returned in that
1207 : * case.
1208 : */
1209 0 : int __pm_runtime_set_status(struct device *dev, unsigned int status)
1210 : {
1211 0 : struct device *parent = dev->parent;
1212 0 : bool notify_parent = false;
1213 0 : int error = 0;
1214 :
1215 0 : if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
1216 : return -EINVAL;
1217 :
1218 0 : spin_lock_irq(&dev->power.lock);
1219 :
1220 : /*
1221 : * Prevent PM-runtime from being enabled for the device or return an
1222 : * error if it is enabled already and working.
1223 : */
1224 0 : if (dev->power.runtime_error || dev->power.disable_depth)
1225 0 : dev->power.disable_depth++;
1226 : else
1227 : error = -EAGAIN;
1228 :
1229 0 : spin_unlock_irq(&dev->power.lock);
1230 :
1231 0 : if (error)
1232 : return error;
1233 :
1234 : /*
1235 : * If the new status is RPM_ACTIVE, the suppliers can be activated
1236 : * upfront regardless of the current status, because next time
1237 : * rpm_put_suppliers() runs, the rpm_active refcounts of the links
1238 : * involved will be dropped down to one anyway.
1239 : */
1240 0 : if (status == RPM_ACTIVE) {
1241 0 : int idx = device_links_read_lock();
1242 :
1243 0 : error = rpm_get_suppliers(dev);
1244 0 : if (error)
1245 0 : status = RPM_SUSPENDED;
1246 :
1247 0 : device_links_read_unlock(idx);
1248 : }
1249 :
1250 0 : spin_lock_irq(&dev->power.lock);
1251 :
1252 0 : if (dev->power.runtime_status == status || !parent)
1253 : goto out_set;
1254 :
1255 0 : if (status == RPM_SUSPENDED) {
1256 0 : atomic_add_unless(&parent->power.child_count, -1, 0);
1257 0 : notify_parent = !parent->power.ignore_children;
1258 : } else {
1259 0 : spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
1260 :
1261 : /*
1262 : * It is invalid to put an active child under a parent that is
1263 : * not active, has runtime PM enabled and the
1264 : * 'power.ignore_children' flag unset.
1265 : */
1266 0 : if (!parent->power.disable_depth
1267 0 : && !parent->power.ignore_children
1268 0 : && parent->power.runtime_status != RPM_ACTIVE) {
1269 0 : dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
1270 : dev_name(dev),
1271 : dev_name(parent));
1272 0 : error = -EBUSY;
1273 0 : } else if (dev->power.runtime_status == RPM_SUSPENDED) {
1274 0 : atomic_inc(&parent->power.child_count);
1275 : }
1276 :
1277 0 : spin_unlock(&parent->power.lock);
1278 :
1279 0 : if (error) {
1280 : status = RPM_SUSPENDED;
1281 : goto out;
1282 : }
1283 : }
1284 :
1285 : out_set:
1286 0 : __update_runtime_status(dev, status);
1287 0 : if (!error)
1288 0 : dev->power.runtime_error = 0;
1289 :
1290 : out:
1291 0 : spin_unlock_irq(&dev->power.lock);
1292 :
1293 0 : if (notify_parent)
1294 : pm_request_idle(parent);
1295 :
1296 0 : if (status == RPM_SUSPENDED) {
1297 0 : int idx = device_links_read_lock();
1298 :
1299 0 : rpm_put_suppliers(dev);
1300 :
1301 0 : device_links_read_unlock(idx);
1302 : }
1303 :
1304 0 : pm_runtime_enable(dev);
1305 :
1306 0 : return error;
1307 : }
1308 : EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
1309 :
1310 : /**
1311 : * __pm_runtime_barrier - Cancel pending requests and wait for completions.
1312 : * @dev: Device to handle.
1313 : *
1314 : * Flush all pending requests for the device from pm_wq and wait for all
1315 : * runtime PM operations involving the device in progress to complete.
1316 : *
1317 : * Should be called under dev->power.lock with interrupts disabled.
1318 : */
1319 536 : static void __pm_runtime_barrier(struct device *dev)
1320 : {
1321 536 : pm_runtime_deactivate_timer(dev);
1322 :
1323 536 : if (dev->power.request_pending) {
1324 0 : dev->power.request = RPM_REQ_NONE;
1325 0 : spin_unlock_irq(&dev->power.lock);
1326 :
1327 0 : cancel_work_sync(&dev->power.work);
1328 :
1329 0 : spin_lock_irq(&dev->power.lock);
1330 0 : dev->power.request_pending = false;
1331 : }
1332 :
1333 1072 : if (dev->power.runtime_status == RPM_SUSPENDING
1334 536 : || dev->power.runtime_status == RPM_RESUMING
1335 536 : || dev->power.idle_notification) {
1336 0 : DEFINE_WAIT(wait);
1337 :
1338 : /* Suspend, wake-up or idle notification in progress. */
1339 : for (;;) {
1340 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
1341 : TASK_UNINTERRUPTIBLE);
1342 0 : if (dev->power.runtime_status != RPM_SUSPENDING
1343 0 : && dev->power.runtime_status != RPM_RESUMING
1344 0 : && !dev->power.idle_notification)
1345 : break;
1346 0 : spin_unlock_irq(&dev->power.lock);
1347 :
1348 0 : schedule();
1349 :
1350 0 : spin_lock_irq(&dev->power.lock);
1351 : }
1352 0 : finish_wait(&dev->power.wait_queue, &wait);
1353 : }
1354 536 : }
1355 :
1356 : /**
1357 : * pm_runtime_barrier - Flush pending requests and wait for completions.
1358 : * @dev: Device to handle.
1359 : *
1360 : * Prevent the device from being suspended by incrementing its usage counter and
1361 : * if there's a pending resume request for the device, wake the device up.
1362 : * Next, make sure that all pending requests for the device have been flushed
1363 : * from pm_wq and wait for all runtime PM operations involving the device in
1364 : * progress to complete.
1365 : *
1366 : * Return value:
1367 : * 1, if there was a resume request pending and the device had to be woken up,
1368 : * 0, otherwise
1369 : */
1370 536 : int pm_runtime_barrier(struct device *dev)
1371 : {
1372 536 : int retval = 0;
1373 :
1374 536 : pm_runtime_get_noresume(dev);
1375 1072 : spin_lock_irq(&dev->power.lock);
1376 :
1377 536 : if (dev->power.request_pending
1378 0 : && dev->power.request == RPM_REQ_RESUME) {
1379 0 : rpm_resume(dev, 0);
1380 0 : retval = 1;
1381 : }
1382 :
1383 536 : __pm_runtime_barrier(dev);
1384 :
1385 1072 : spin_unlock_irq(&dev->power.lock);
1386 536 : pm_runtime_put_noidle(dev);
1387 :
1388 536 : return retval;
1389 : }
1390 : EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1391 :
1392 : /**
1393 : * __pm_runtime_disable - Disable runtime PM of a device.
1394 : * @dev: Device to handle.
1395 : * @check_resume: If set, check if there's a resume request for the device.
1396 : *
1397 : * Increment power.disable_depth for the device and if it was zero previously,
1398 : * cancel all pending runtime PM requests for the device and wait for all
1399 : * operations in progress to complete. The device can be either active or
1400 : * suspended after its runtime PM has been disabled.
1401 : *
1402 : * If @check_resume is set and there's a resume request pending when
1403 : * __pm_runtime_disable() is called and power.disable_depth is zero, the
1404 : * function will wake up the device before disabling its runtime PM.
1405 : */
1406 0 : void __pm_runtime_disable(struct device *dev, bool check_resume)
1407 : {
1408 0 : spin_lock_irq(&dev->power.lock);
1409 :
1410 0 : if (dev->power.disable_depth > 0) {
1411 0 : dev->power.disable_depth++;
1412 0 : goto out;
1413 : }
1414 :
1415 : /*
1416 : * Wake up the device if there's a resume request pending, because that
1417 : * means there probably is some I/O to process and disabling runtime PM
1418 : * shouldn't prevent the device from processing the I/O.
1419 : */
1420 0 : if (check_resume && dev->power.request_pending
1421 0 : && dev->power.request == RPM_REQ_RESUME) {
1422 : /*
1423 : * Prevent suspends and idle notifications from being carried
1424 : * out after we have woken up the device.
1425 : */
1426 0 : pm_runtime_get_noresume(dev);
1427 :
1428 0 : rpm_resume(dev, 0);
1429 :
1430 : pm_runtime_put_noidle(dev);
1431 : }
1432 :
1433 : /* Update time accounting before disabling PM-runtime. */
1434 0 : update_pm_runtime_accounting(dev);
1435 :
1436 0 : if (!dev->power.disable_depth++) {
1437 0 : __pm_runtime_barrier(dev);
1438 0 : dev->power.last_status = dev->power.runtime_status;
1439 : }
1440 :
1441 : out:
1442 0 : spin_unlock_irq(&dev->power.lock);
1443 0 : }
1444 : EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1445 :
1446 : /**
1447 : * pm_runtime_enable - Enable runtime PM of a device.
1448 : * @dev: Device to handle.
1449 : */
1450 0 : void pm_runtime_enable(struct device *dev)
1451 : {
1452 : unsigned long flags;
1453 :
1454 0 : spin_lock_irqsave(&dev->power.lock, flags);
1455 :
1456 0 : if (!dev->power.disable_depth) {
1457 0 : dev_warn(dev, "Unbalanced %s!\n", __func__);
1458 0 : goto out;
1459 : }
1460 :
1461 0 : if (--dev->power.disable_depth > 0)
1462 : goto out;
1463 :
1464 0 : dev->power.last_status = RPM_INVALID;
1465 0 : dev->power.accounting_timestamp = ktime_get_mono_fast_ns();
1466 :
1467 0 : if (dev->power.runtime_status == RPM_SUSPENDED &&
1468 0 : !dev->power.ignore_children &&
1469 0 : atomic_read(&dev->power.child_count) > 0)
1470 0 : dev_warn(dev, "Enabling runtime PM for inactive device with active children\n");
1471 :
1472 : out:
1473 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1474 0 : }
1475 : EXPORT_SYMBOL_GPL(pm_runtime_enable);
1476 :
1477 0 : static void pm_runtime_disable_action(void *data)
1478 : {
1479 0 : pm_runtime_dont_use_autosuspend(data);
1480 0 : pm_runtime_disable(data);
1481 0 : }
1482 :
1483 : /**
1484 : * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.
1485 : *
1486 : * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for
1487 : * you at driver exit time if needed.
1488 : *
1489 : * @dev: Device to handle.
1490 : */
1491 0 : int devm_pm_runtime_enable(struct device *dev)
1492 : {
1493 0 : pm_runtime_enable(dev);
1494 :
1495 0 : return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);
1496 : }
1497 : EXPORT_SYMBOL_GPL(devm_pm_runtime_enable);
1498 :
1499 : /**
1500 : * pm_runtime_forbid - Block runtime PM of a device.
1501 : * @dev: Device to handle.
1502 : *
1503 : * Increase the device's usage count and clear its power.runtime_auto flag,
1504 : * so that it cannot be suspended at run time until pm_runtime_allow() is called
1505 : * for it.
1506 : */
1507 0 : void pm_runtime_forbid(struct device *dev)
1508 : {
1509 0 : spin_lock_irq(&dev->power.lock);
1510 0 : if (!dev->power.runtime_auto)
1511 : goto out;
1512 :
1513 0 : dev->power.runtime_auto = false;
1514 0 : atomic_inc(&dev->power.usage_count);
1515 0 : rpm_resume(dev, 0);
1516 :
1517 : out:
1518 0 : spin_unlock_irq(&dev->power.lock);
1519 0 : }
1520 : EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1521 :
1522 : /**
1523 : * pm_runtime_allow - Unblock runtime PM of a device.
1524 : * @dev: Device to handle.
1525 : *
1526 : * Decrease the device's usage count and set its power.runtime_auto flag.
1527 : */
1528 0 : void pm_runtime_allow(struct device *dev)
1529 : {
1530 0 : spin_lock_irq(&dev->power.lock);
1531 0 : if (dev->power.runtime_auto)
1532 : goto out;
1533 :
1534 0 : dev->power.runtime_auto = true;
1535 0 : if (atomic_dec_and_test(&dev->power.usage_count))
1536 0 : rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
1537 : else
1538 : trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
1539 :
1540 : out:
1541 0 : spin_unlock_irq(&dev->power.lock);
1542 0 : }
1543 : EXPORT_SYMBOL_GPL(pm_runtime_allow);
1544 :
1545 : /**
1546 : * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1547 : * @dev: Device to handle.
1548 : *
1549 : * Set the power.no_callbacks flag, which tells the PM core that this
1550 : * device is power-managed through its parent and has no runtime PM
1551 : * callbacks of its own. The runtime sysfs attributes will be removed.
1552 : */
1553 0 : void pm_runtime_no_callbacks(struct device *dev)
1554 : {
1555 0 : spin_lock_irq(&dev->power.lock);
1556 0 : dev->power.no_callbacks = 1;
1557 0 : spin_unlock_irq(&dev->power.lock);
1558 0 : if (device_is_registered(dev))
1559 0 : rpm_sysfs_remove(dev);
1560 0 : }
1561 : EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1562 :
1563 : /**
1564 : * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1565 : * @dev: Device to handle
1566 : *
1567 : * Set the power.irq_safe flag, which tells the PM core that the
1568 : * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1569 : * always be invoked with the spinlock held and interrupts disabled. It also
1570 : * causes the parent's usage counter to be permanently incremented, preventing
1571 : * the parent from runtime suspending -- otherwise an irq-safe child might have
1572 : * to wait for a non-irq-safe parent.
1573 : */
1574 0 : void pm_runtime_irq_safe(struct device *dev)
1575 : {
1576 0 : if (dev->parent)
1577 0 : pm_runtime_get_sync(dev->parent);
1578 0 : spin_lock_irq(&dev->power.lock);
1579 0 : dev->power.irq_safe = 1;
1580 0 : spin_unlock_irq(&dev->power.lock);
1581 0 : }
1582 : EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1583 :
1584 : /**
1585 : * update_autosuspend - Handle a change to a device's autosuspend settings.
1586 : * @dev: Device to handle.
1587 : * @old_delay: The former autosuspend_delay value.
1588 : * @old_use: The former use_autosuspend value.
1589 : *
1590 : * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1591 : * set; otherwise allow it. Send an idle notification if suspends are allowed.
1592 : *
1593 : * This function must be called under dev->power.lock with interrupts disabled.
1594 : */
1595 0 : static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1596 : {
1597 0 : int delay = dev->power.autosuspend_delay;
1598 :
1599 : /* Should runtime suspend be prevented now? */
1600 0 : if (dev->power.use_autosuspend && delay < 0) {
1601 :
1602 : /* If it used to be allowed then prevent it. */
1603 0 : if (!old_use || old_delay >= 0) {
1604 0 : atomic_inc(&dev->power.usage_count);
1605 0 : rpm_resume(dev, 0);
1606 : } else {
1607 : trace_rpm_usage_rcuidle(dev, 0);
1608 : }
1609 : }
1610 :
1611 : /* Runtime suspend should be allowed now. */
1612 : else {
1613 :
1614 : /* If it used to be prevented then allow it. */
1615 0 : if (old_use && old_delay < 0)
1616 0 : atomic_dec(&dev->power.usage_count);
1617 :
1618 : /* Maybe we can autosuspend now. */
1619 0 : rpm_idle(dev, RPM_AUTO);
1620 : }
1621 0 : }
1622 :
1623 : /**
1624 : * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1625 : * @dev: Device to handle.
1626 : * @delay: Value of the new delay in milliseconds.
1627 : *
1628 : * Set the device's power.autosuspend_delay value. If it changes to negative
1629 : * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1630 : * changes the other way, allow runtime suspends.
1631 : */
1632 0 : void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1633 : {
1634 : int old_delay, old_use;
1635 :
1636 0 : spin_lock_irq(&dev->power.lock);
1637 0 : old_delay = dev->power.autosuspend_delay;
1638 0 : old_use = dev->power.use_autosuspend;
1639 0 : dev->power.autosuspend_delay = delay;
1640 0 : update_autosuspend(dev, old_delay, old_use);
1641 0 : spin_unlock_irq(&dev->power.lock);
1642 0 : }
1643 : EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1644 :
1645 : /**
1646 : * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1647 : * @dev: Device to handle.
1648 : * @use: New value for use_autosuspend.
1649 : *
1650 : * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1651 : * suspends as needed.
1652 : */
1653 0 : void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1654 : {
1655 : int old_delay, old_use;
1656 :
1657 0 : spin_lock_irq(&dev->power.lock);
1658 0 : old_delay = dev->power.autosuspend_delay;
1659 0 : old_use = dev->power.use_autosuspend;
1660 0 : dev->power.use_autosuspend = use;
1661 0 : update_autosuspend(dev, old_delay, old_use);
1662 0 : spin_unlock_irq(&dev->power.lock);
1663 0 : }
1664 : EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1665 :
1666 : /**
1667 : * pm_runtime_init - Initialize runtime PM fields in given device object.
1668 : * @dev: Device object to initialize.
1669 : */
1670 536 : void pm_runtime_init(struct device *dev)
1671 : {
1672 536 : dev->power.runtime_status = RPM_SUSPENDED;
1673 536 : dev->power.last_status = RPM_INVALID;
1674 536 : dev->power.idle_notification = false;
1675 :
1676 536 : dev->power.disable_depth = 1;
1677 1072 : atomic_set(&dev->power.usage_count, 0);
1678 :
1679 536 : dev->power.runtime_error = 0;
1680 :
1681 1072 : atomic_set(&dev->power.child_count, 0);
1682 536 : pm_suspend_ignore_children(dev, false);
1683 536 : dev->power.runtime_auto = true;
1684 :
1685 536 : dev->power.request_pending = false;
1686 536 : dev->power.request = RPM_REQ_NONE;
1687 536 : dev->power.deferred_resume = false;
1688 536 : dev->power.needs_force_resume = 0;
1689 1072 : INIT_WORK(&dev->power.work, pm_runtime_work);
1690 :
1691 536 : dev->power.timer_expires = 0;
1692 536 : hrtimer_init(&dev->power.suspend_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1693 536 : dev->power.suspend_timer.function = pm_suspend_timer_fn;
1694 :
1695 536 : init_waitqueue_head(&dev->power.wait_queue);
1696 536 : }
1697 :
1698 : /**
1699 : * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
1700 : * @dev: Device object to re-initialize.
1701 : */
1702 0 : void pm_runtime_reinit(struct device *dev)
1703 : {
1704 0 : if (!pm_runtime_enabled(dev)) {
1705 0 : if (dev->power.runtime_status == RPM_ACTIVE)
1706 : pm_runtime_set_suspended(dev);
1707 0 : if (dev->power.irq_safe) {
1708 0 : spin_lock_irq(&dev->power.lock);
1709 0 : dev->power.irq_safe = 0;
1710 0 : spin_unlock_irq(&dev->power.lock);
1711 0 : if (dev->parent)
1712 0 : pm_runtime_put(dev->parent);
1713 : }
1714 : }
1715 0 : }
1716 :
1717 : /**
1718 : * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1719 : * @dev: Device object being removed from device hierarchy.
1720 : */
1721 0 : void pm_runtime_remove(struct device *dev)
1722 : {
1723 0 : __pm_runtime_disable(dev, false);
1724 0 : pm_runtime_reinit(dev);
1725 0 : }
1726 :
1727 : /**
1728 : * pm_runtime_get_suppliers - Resume and reference-count supplier devices.
1729 : * @dev: Consumer device.
1730 : */
1731 0 : void pm_runtime_get_suppliers(struct device *dev)
1732 : {
1733 : struct device_link *link;
1734 : int idx;
1735 :
1736 0 : idx = device_links_read_lock();
1737 :
1738 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
1739 : device_links_read_lock_held())
1740 0 : if (link->flags & DL_FLAG_PM_RUNTIME) {
1741 0 : link->supplier_preactivated = true;
1742 0 : pm_runtime_get_sync(link->supplier);
1743 0 : refcount_inc(&link->rpm_active);
1744 : }
1745 :
1746 0 : device_links_read_unlock(idx);
1747 0 : }
1748 :
1749 : /**
1750 : * pm_runtime_put_suppliers - Drop references to supplier devices.
1751 : * @dev: Consumer device.
1752 : */
1753 0 : void pm_runtime_put_suppliers(struct device *dev)
1754 : {
1755 : struct device_link *link;
1756 : int idx;
1757 :
1758 0 : idx = device_links_read_lock();
1759 :
1760 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
1761 : device_links_read_lock_held())
1762 0 : if (link->supplier_preactivated) {
1763 : bool put;
1764 :
1765 0 : link->supplier_preactivated = false;
1766 :
1767 0 : spin_lock_irq(&dev->power.lock);
1768 :
1769 0 : put = pm_runtime_status_suspended(dev) &&
1770 0 : refcount_dec_not_one(&link->rpm_active);
1771 :
1772 0 : spin_unlock_irq(&dev->power.lock);
1773 :
1774 0 : if (put)
1775 0 : pm_runtime_put(link->supplier);
1776 : }
1777 :
1778 0 : device_links_read_unlock(idx);
1779 0 : }
1780 :
1781 0 : void pm_runtime_new_link(struct device *dev)
1782 : {
1783 0 : spin_lock_irq(&dev->power.lock);
1784 0 : dev->power.links_count++;
1785 0 : spin_unlock_irq(&dev->power.lock);
1786 0 : }
1787 :
1788 0 : static void pm_runtime_drop_link_count(struct device *dev)
1789 : {
1790 0 : spin_lock_irq(&dev->power.lock);
1791 0 : WARN_ON(dev->power.links_count == 0);
1792 0 : dev->power.links_count--;
1793 0 : spin_unlock_irq(&dev->power.lock);
1794 0 : }
1795 :
1796 : /**
1797 : * pm_runtime_drop_link - Prepare for device link removal.
1798 : * @link: Device link going away.
1799 : *
1800 : * Drop the link count of the consumer end of @link and decrement the supplier
1801 : * device's runtime PM usage counter as many times as needed to drop all of the
1802 : * PM runtime reference to it from the consumer.
1803 : */
1804 0 : void pm_runtime_drop_link(struct device_link *link)
1805 : {
1806 0 : if (!(link->flags & DL_FLAG_PM_RUNTIME))
1807 : return;
1808 :
1809 0 : pm_runtime_drop_link_count(link->consumer);
1810 0 : pm_runtime_release_supplier(link, true);
1811 : }
1812 :
1813 : static bool pm_runtime_need_not_resume(struct device *dev)
1814 : {
1815 0 : return atomic_read(&dev->power.usage_count) <= 1 &&
1816 0 : (atomic_read(&dev->power.child_count) == 0 ||
1817 : dev->power.ignore_children);
1818 : }
1819 :
1820 : /**
1821 : * pm_runtime_force_suspend - Force a device into suspend state if needed.
1822 : * @dev: Device to suspend.
1823 : *
1824 : * Disable runtime PM so we safely can check the device's runtime PM status and
1825 : * if it is active, invoke its ->runtime_suspend callback to suspend it and
1826 : * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's
1827 : * usage and children counters don't indicate that the device was in use before
1828 : * the system-wide transition under way, decrement its parent's children counter
1829 : * (if there is a parent). Keep runtime PM disabled to preserve the state
1830 : * unless we encounter errors.
1831 : *
1832 : * Typically this function may be invoked from a system suspend callback to make
1833 : * sure the device is put into low power state and it should only be used during
1834 : * system-wide PM transitions to sleep states. It assumes that the analogous
1835 : * pm_runtime_force_resume() will be used to resume the device.
1836 : */
1837 0 : int pm_runtime_force_suspend(struct device *dev)
1838 : {
1839 : int (*callback)(struct device *);
1840 : int ret;
1841 :
1842 0 : pm_runtime_disable(dev);
1843 0 : if (pm_runtime_status_suspended(dev))
1844 : return 0;
1845 :
1846 0 : callback = RPM_GET_CALLBACK(dev, runtime_suspend);
1847 :
1848 0 : ret = callback ? callback(dev) : 0;
1849 0 : if (ret)
1850 : goto err;
1851 :
1852 : /*
1853 : * If the device can stay in suspend after the system-wide transition
1854 : * to the working state that will follow, drop the children counter of
1855 : * its parent, but set its status to RPM_SUSPENDED anyway in case this
1856 : * function will be called again for it in the meantime.
1857 : */
1858 0 : if (pm_runtime_need_not_resume(dev)) {
1859 : pm_runtime_set_suspended(dev);
1860 : } else {
1861 0 : __update_runtime_status(dev, RPM_SUSPENDED);
1862 0 : dev->power.needs_force_resume = 1;
1863 : }
1864 :
1865 : return 0;
1866 :
1867 : err:
1868 0 : pm_runtime_enable(dev);
1869 0 : return ret;
1870 : }
1871 : EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
1872 :
1873 : /**
1874 : * pm_runtime_force_resume - Force a device into resume state if needed.
1875 : * @dev: Device to resume.
1876 : *
1877 : * Prior invoking this function we expect the user to have brought the device
1878 : * into low power state by a call to pm_runtime_force_suspend(). Here we reverse
1879 : * those actions and bring the device into full power, if it is expected to be
1880 : * used on system resume. In the other case, we defer the resume to be managed
1881 : * via runtime PM.
1882 : *
1883 : * Typically this function may be invoked from a system resume callback.
1884 : */
1885 0 : int pm_runtime_force_resume(struct device *dev)
1886 : {
1887 : int (*callback)(struct device *);
1888 0 : int ret = 0;
1889 :
1890 0 : if (!pm_runtime_status_suspended(dev) || !dev->power.needs_force_resume)
1891 : goto out;
1892 :
1893 : /*
1894 : * The value of the parent's children counter is correct already, so
1895 : * just update the status of the device.
1896 : */
1897 0 : __update_runtime_status(dev, RPM_ACTIVE);
1898 :
1899 0 : callback = RPM_GET_CALLBACK(dev, runtime_resume);
1900 :
1901 0 : ret = callback ? callback(dev) : 0;
1902 0 : if (ret) {
1903 : pm_runtime_set_suspended(dev);
1904 : goto out;
1905 : }
1906 :
1907 : pm_runtime_mark_last_busy(dev);
1908 : out:
1909 0 : dev->power.needs_force_resume = 0;
1910 0 : pm_runtime_enable(dev);
1911 0 : return ret;
1912 : }
1913 : EXPORT_SYMBOL_GPL(pm_runtime_force_resume);
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