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 : {
131 540 : 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, dev_memalloc_noio)))
247 : break;
248 : }
249 0 : mutex_unlock(&dev_hotplug_mutex);
250 0 : }
251 : EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
252 :
253 : /**
254 : * rpm_check_suspend_allowed - Test whether a device may be suspended.
255 : * @dev: Device to test.
256 : */
257 24 : static int rpm_check_suspend_allowed(struct device *dev)
258 : {
259 24 : int retval = 0;
260 :
261 24 : if (dev->power.runtime_error)
262 : retval = -EINVAL;
263 24 : else if (dev->power.disable_depth > 0)
264 : retval = -EACCES;
265 0 : else if (atomic_read(&dev->power.usage_count))
266 : retval = -EAGAIN;
267 0 : else if (!dev->power.ignore_children && atomic_read(&dev->power.child_count))
268 : retval = -EBUSY;
269 :
270 : /* Pending resume requests take precedence over suspends. */
271 0 : else if ((dev->power.deferred_resume &&
272 0 : dev->power.runtime_status == RPM_SUSPENDING) ||
273 0 : (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME))
274 : retval = -EAGAIN;
275 0 : else if (__dev_pm_qos_resume_latency(dev) == 0)
276 : retval = -EPERM;
277 0 : else if (dev->power.runtime_status == RPM_SUSPENDED)
278 0 : retval = 1;
279 :
280 24 : return retval;
281 : }
282 :
283 0 : static int rpm_get_suppliers(struct device *dev)
284 : {
285 : struct device_link *link;
286 :
287 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
288 : device_links_read_lock_held()) {
289 : int retval;
290 :
291 0 : if (!(link->flags & DL_FLAG_PM_RUNTIME))
292 0 : continue;
293 :
294 0 : retval = pm_runtime_get_sync(link->supplier);
295 : /* Ignore suppliers with disabled runtime PM. */
296 0 : if (retval < 0 && retval != -EACCES) {
297 0 : pm_runtime_put_noidle(link->supplier);
298 : return retval;
299 : }
300 0 : refcount_inc(&link->rpm_active);
301 : }
302 : return 0;
303 : }
304 :
305 : /**
306 : * pm_runtime_release_supplier - Drop references to device link's supplier.
307 : * @link: Target device link.
308 : *
309 : * Drop all runtime PM references associated with @link to its supplier device.
310 : */
311 0 : void pm_runtime_release_supplier(struct device_link *link)
312 : {
313 0 : struct device *supplier = link->supplier;
314 :
315 : /*
316 : * The additional power.usage_count check is a safety net in case
317 : * the rpm_active refcount becomes saturated, in which case
318 : * refcount_dec_not_one() would return true forever, but it is not
319 : * strictly necessary.
320 : */
321 0 : while (refcount_dec_not_one(&link->rpm_active) &&
322 0 : atomic_read(&supplier->power.usage_count) > 0)
323 : pm_runtime_put_noidle(supplier);
324 0 : }
325 :
326 0 : static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
327 : {
328 : struct device_link *link;
329 :
330 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
331 : device_links_read_lock_held()) {
332 0 : pm_runtime_release_supplier(link);
333 0 : if (try_to_suspend)
334 0 : pm_request_idle(link->supplier);
335 : }
336 0 : }
337 :
338 0 : static void rpm_put_suppliers(struct device *dev)
339 : {
340 0 : __rpm_put_suppliers(dev, true);
341 0 : }
342 :
343 0 : static void rpm_suspend_suppliers(struct device *dev)
344 : {
345 : struct device_link *link;
346 0 : int idx = device_links_read_lock();
347 :
348 0 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
349 : device_links_read_lock_held())
350 0 : pm_request_idle(link->supplier);
351 :
352 0 : device_links_read_unlock(idx);
353 0 : }
354 :
355 : /**
356 : * __rpm_callback - Run a given runtime PM callback for a given device.
357 : * @cb: Runtime PM callback to run.
358 : * @dev: Device to run the callback for.
359 : */
360 0 : static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
361 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
362 : {
363 0 : int retval = 0, idx;
364 0 : bool use_links = dev->power.links_count > 0;
365 :
366 0 : if (dev->power.irq_safe) {
367 0 : spin_unlock(&dev->power.lock);
368 : } else {
369 0 : spin_unlock_irq(&dev->power.lock);
370 :
371 : /*
372 : * Resume suppliers if necessary.
373 : *
374 : * The device's runtime PM status cannot change until this
375 : * routine returns, so it is safe to read the status outside of
376 : * the lock.
377 : */
378 0 : if (use_links && dev->power.runtime_status == RPM_RESUMING) {
379 0 : idx = device_links_read_lock();
380 :
381 0 : retval = rpm_get_suppliers(dev);
382 0 : if (retval) {
383 0 : rpm_put_suppliers(dev);
384 0 : goto fail;
385 : }
386 :
387 0 : device_links_read_unlock(idx);
388 : }
389 : }
390 :
391 0 : if (cb)
392 0 : retval = cb(dev);
393 :
394 0 : if (dev->power.irq_safe) {
395 0 : spin_lock(&dev->power.lock);
396 : } else {
397 : /*
398 : * If the device is suspending and the callback has returned
399 : * success, drop the usage counters of the suppliers that have
400 : * been reference counted on its resume.
401 : *
402 : * Do that if resume fails too.
403 : */
404 0 : if (use_links &&
405 0 : ((dev->power.runtime_status == RPM_SUSPENDING && !retval) ||
406 0 : (dev->power.runtime_status == RPM_RESUMING && retval))) {
407 0 : idx = device_links_read_lock();
408 :
409 0 : __rpm_put_suppliers(dev, false);
410 :
411 : fail:
412 0 : device_links_read_unlock(idx);
413 : }
414 :
415 0 : spin_lock_irq(&dev->power.lock);
416 : }
417 :
418 0 : return retval;
419 : }
420 :
421 : /**
422 : * rpm_callback - Run a given runtime PM callback for a given device.
423 : * @cb: Runtime PM callback to run.
424 : * @dev: Device to run the callback for.
425 : */
426 0 : static int rpm_callback(int (*cb)(struct device *), struct device *dev)
427 : {
428 : int retval;
429 :
430 0 : if (dev->power.memalloc_noio) {
431 : unsigned int noio_flag;
432 :
433 : /*
434 : * Deadlock might be caused if memory allocation with
435 : * GFP_KERNEL happens inside runtime_suspend and
436 : * runtime_resume callbacks of one block device's
437 : * ancestor or the block device itself. Network
438 : * device might be thought as part of iSCSI block
439 : * device, so network device and its ancestor should
440 : * be marked as memalloc_noio too.
441 : */
442 0 : noio_flag = memalloc_noio_save();
443 0 : retval = __rpm_callback(cb, dev);
444 : memalloc_noio_restore(noio_flag);
445 : } else {
446 0 : retval = __rpm_callback(cb, dev);
447 : }
448 :
449 0 : dev->power.runtime_error = retval;
450 0 : return retval != -EACCES ? retval : -EIO;
451 : }
452 :
453 : /**
454 : * rpm_idle - Notify device bus type if the device can be suspended.
455 : * @dev: Device to notify the bus type about.
456 : * @rpmflags: Flag bits.
457 : *
458 : * Check if the device's runtime PM status allows it to be suspended. If
459 : * another idle notification has been started earlier, return immediately. If
460 : * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
461 : * run the ->runtime_idle() callback directly. If the ->runtime_idle callback
462 : * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
463 : *
464 : * This function must be called under dev->power.lock with interrupts disabled.
465 : */
466 24 : static int rpm_idle(struct device *dev, int rpmflags)
467 : {
468 : int (*callback)(struct device *);
469 : int retval;
470 :
471 24 : trace_rpm_idle(dev, rpmflags);
472 24 : retval = rpm_check_suspend_allowed(dev);
473 24 : if (retval < 0)
474 : ; /* Conditions are wrong. */
475 :
476 : /* Idle notifications are allowed only in the RPM_ACTIVE state. */
477 0 : else if (dev->power.runtime_status != RPM_ACTIVE)
478 : retval = -EAGAIN;
479 :
480 : /*
481 : * Any pending request other than an idle notification takes
482 : * precedence over us, except that the timer may be running.
483 : */
484 0 : else if (dev->power.request_pending &&
485 0 : dev->power.request > RPM_REQ_IDLE)
486 : retval = -EAGAIN;
487 :
488 : /* Act as though RPM_NOWAIT is always set. */
489 0 : else if (dev->power.idle_notification)
490 0 : retval = -EINPROGRESS;
491 :
492 24 : if (retval)
493 : goto out;
494 :
495 : /* Pending requests need to be canceled. */
496 0 : dev->power.request = RPM_REQ_NONE;
497 :
498 0 : callback = RPM_GET_CALLBACK(dev, runtime_idle);
499 :
500 : /* If no callback assume success. */
501 0 : if (!callback || dev->power.no_callbacks)
502 : goto out;
503 :
504 : /* Carry out an asynchronous or a synchronous idle notification. */
505 0 : if (rpmflags & RPM_ASYNC) {
506 0 : dev->power.request = RPM_REQ_IDLE;
507 0 : if (!dev->power.request_pending) {
508 0 : dev->power.request_pending = true;
509 0 : queue_work(pm_wq, &dev->power.work);
510 : }
511 0 : trace_rpm_return_int(dev, _THIS_IP_, 0);
512 0 : return 0;
513 : }
514 :
515 0 : dev->power.idle_notification = true;
516 :
517 0 : if (dev->power.irq_safe)
518 0 : spin_unlock(&dev->power.lock);
519 : else
520 0 : spin_unlock_irq(&dev->power.lock);
521 :
522 0 : retval = callback(dev);
523 :
524 0 : if (dev->power.irq_safe)
525 0 : spin_lock(&dev->power.lock);
526 : else
527 0 : spin_lock_irq(&dev->power.lock);
528 :
529 0 : dev->power.idle_notification = false;
530 0 : wake_up_all(&dev->power.wait_queue);
531 :
532 : out:
533 24 : trace_rpm_return_int(dev, _THIS_IP_, retval);
534 24 : return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
535 : }
536 :
537 : /**
538 : * rpm_suspend - Carry out runtime suspend of given device.
539 : * @dev: Device to suspend.
540 : * @rpmflags: Flag bits.
541 : *
542 : * Check if the device's runtime PM status allows it to be suspended.
543 : * Cancel a pending idle notification, autosuspend or suspend. If
544 : * another suspend has been started earlier, either return immediately
545 : * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
546 : * flags. If the RPM_ASYNC flag is set then queue a suspend request;
547 : * otherwise run the ->runtime_suspend() callback directly. When
548 : * ->runtime_suspend succeeded, if a deferred resume was requested while
549 : * the callback was running then carry it out, otherwise send an idle
550 : * notification for its parent (if the suspend succeeded and both
551 : * ignore_children of parent->power and irq_safe of dev->power are not set).
552 : * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
553 : * flag is set and the next autosuspend-delay expiration time is in the
554 : * future, schedule another autosuspend attempt.
555 : *
556 : * This function must be called under dev->power.lock with interrupts disabled.
557 : */
558 0 : static int rpm_suspend(struct device *dev, int rpmflags)
559 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
560 : {
561 : int (*callback)(struct device *);
562 0 : struct device *parent = NULL;
563 : int retval;
564 :
565 0 : trace_rpm_suspend(dev, rpmflags);
566 :
567 : repeat:
568 0 : retval = rpm_check_suspend_allowed(dev);
569 0 : if (retval < 0)
570 : goto out; /* Conditions are wrong. */
571 :
572 : /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
573 0 : if (dev->power.runtime_status == RPM_RESUMING && !(rpmflags & RPM_ASYNC))
574 0 : retval = -EAGAIN;
575 :
576 0 : if (retval)
577 : goto out;
578 :
579 : /* If the autosuspend_delay time hasn't expired yet, reschedule. */
580 0 : if ((rpmflags & RPM_AUTO) && dev->power.runtime_status != RPM_SUSPENDING) {
581 0 : u64 expires = pm_runtime_autosuspend_expiration(dev);
582 :
583 0 : if (expires != 0) {
584 : /* Pending requests need to be canceled. */
585 0 : dev->power.request = RPM_REQ_NONE;
586 :
587 : /*
588 : * Optimization: If the timer is already running and is
589 : * set to expire at or before the autosuspend delay,
590 : * avoid the overhead of resetting it. Just let it
591 : * expire; pm_suspend_timer_fn() will take care of the
592 : * rest.
593 : */
594 0 : if (!(dev->power.timer_expires &&
595 : dev->power.timer_expires <= expires)) {
596 : /*
597 : * We add a slack of 25% to gather wakeups
598 : * without sacrificing the granularity.
599 : */
600 0 : u64 slack = (u64)READ_ONCE(dev->power.autosuspend_delay) *
601 : (NSEC_PER_MSEC >> 2);
602 :
603 0 : dev->power.timer_expires = expires;
604 0 : hrtimer_start_range_ns(&dev->power.suspend_timer,
605 : ns_to_ktime(expires),
606 : slack,
607 : HRTIMER_MODE_ABS);
608 : }
609 0 : dev->power.timer_autosuspends = 1;
610 0 : goto out;
611 : }
612 : }
613 :
614 : /* Other scheduled or pending requests need to be canceled. */
615 0 : pm_runtime_cancel_pending(dev);
616 :
617 0 : if (dev->power.runtime_status == RPM_SUSPENDING) {
618 0 : DEFINE_WAIT(wait);
619 :
620 0 : if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
621 0 : retval = -EINPROGRESS;
622 0 : goto out;
623 : }
624 :
625 0 : if (dev->power.irq_safe) {
626 0 : spin_unlock(&dev->power.lock);
627 :
628 : cpu_relax();
629 :
630 0 : spin_lock(&dev->power.lock);
631 0 : goto repeat;
632 : }
633 :
634 : /* Wait for the other suspend running in parallel with us. */
635 : for (;;) {
636 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
637 : TASK_UNINTERRUPTIBLE);
638 0 : if (dev->power.runtime_status != RPM_SUSPENDING)
639 : break;
640 :
641 0 : spin_unlock_irq(&dev->power.lock);
642 :
643 0 : schedule();
644 :
645 0 : spin_lock_irq(&dev->power.lock);
646 : }
647 0 : finish_wait(&dev->power.wait_queue, &wait);
648 0 : goto repeat;
649 : }
650 :
651 0 : if (dev->power.no_callbacks)
652 : goto no_callback; /* Assume success. */
653 :
654 : /* Carry out an asynchronous or a synchronous suspend. */
655 0 : if (rpmflags & RPM_ASYNC) {
656 0 : dev->power.request = (rpmflags & RPM_AUTO) ?
657 0 : RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
658 0 : if (!dev->power.request_pending) {
659 0 : dev->power.request_pending = true;
660 0 : queue_work(pm_wq, &dev->power.work);
661 : }
662 : goto out;
663 : }
664 :
665 0 : __update_runtime_status(dev, RPM_SUSPENDING);
666 :
667 0 : callback = RPM_GET_CALLBACK(dev, runtime_suspend);
668 :
669 0 : dev_pm_enable_wake_irq_check(dev, true);
670 0 : retval = rpm_callback(callback, dev);
671 0 : if (retval)
672 : goto fail;
673 :
674 0 : dev_pm_enable_wake_irq_complete(dev);
675 :
676 : no_callback:
677 0 : __update_runtime_status(dev, RPM_SUSPENDED);
678 0 : pm_runtime_deactivate_timer(dev);
679 :
680 0 : if (dev->parent) {
681 0 : parent = dev->parent;
682 0 : atomic_add_unless(&parent->power.child_count, -1, 0);
683 : }
684 0 : wake_up_all(&dev->power.wait_queue);
685 :
686 0 : if (dev->power.deferred_resume) {
687 0 : dev->power.deferred_resume = false;
688 0 : rpm_resume(dev, 0);
689 0 : retval = -EAGAIN;
690 0 : goto out;
691 : }
692 :
693 0 : if (dev->power.irq_safe)
694 : goto out;
695 :
696 : /* Maybe the parent is now able to suspend. */
697 0 : if (parent && !parent->power.ignore_children) {
698 0 : spin_unlock(&dev->power.lock);
699 :
700 0 : spin_lock(&parent->power.lock);
701 0 : rpm_idle(parent, RPM_ASYNC);
702 0 : spin_unlock(&parent->power.lock);
703 :
704 0 : spin_lock(&dev->power.lock);
705 : }
706 : /* Maybe the suppliers are now able to suspend. */
707 0 : if (dev->power.links_count > 0) {
708 0 : spin_unlock_irq(&dev->power.lock);
709 :
710 0 : rpm_suspend_suppliers(dev);
711 :
712 0 : spin_lock_irq(&dev->power.lock);
713 : }
714 :
715 : out:
716 0 : trace_rpm_return_int(dev, _THIS_IP_, retval);
717 :
718 0 : return retval;
719 :
720 : fail:
721 0 : dev_pm_disable_wake_irq_check(dev, true);
722 0 : __update_runtime_status(dev, RPM_ACTIVE);
723 0 : dev->power.deferred_resume = false;
724 0 : wake_up_all(&dev->power.wait_queue);
725 :
726 0 : if (retval == -EAGAIN || retval == -EBUSY) {
727 0 : dev->power.runtime_error = 0;
728 :
729 : /*
730 : * If the callback routine failed an autosuspend, and
731 : * if the last_busy time has been updated so that there
732 : * is a new autosuspend expiration time, automatically
733 : * reschedule another autosuspend.
734 : */
735 0 : if ((rpmflags & RPM_AUTO) &&
736 0 : pm_runtime_autosuspend_expiration(dev) != 0)
737 : goto repeat;
738 : } else {
739 : pm_runtime_cancel_pending(dev);
740 : }
741 : goto out;
742 : }
743 :
744 : /**
745 : * rpm_resume - Carry out runtime resume of given device.
746 : * @dev: Device to resume.
747 : * @rpmflags: Flag bits.
748 : *
749 : * Check if the device's runtime PM status allows it to be resumed. Cancel
750 : * any scheduled or pending requests. If another resume has been started
751 : * earlier, either return immediately or wait for it to finish, depending on the
752 : * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
753 : * parallel with this function, either tell the other process to resume after
754 : * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
755 : * flag is set then queue a resume request; otherwise run the
756 : * ->runtime_resume() callback directly. Queue an idle notification for the
757 : * device if the resume succeeded.
758 : *
759 : * This function must be called under dev->power.lock with interrupts disabled.
760 : */
761 15 : static int rpm_resume(struct device *dev, int rpmflags)
762 : __releases(&dev->power.lock) __acquires(&dev->power.lock)
763 : {
764 : int (*callback)(struct device *);
765 15 : struct device *parent = NULL;
766 15 : int retval = 0;
767 :
768 15 : trace_rpm_resume(dev, rpmflags);
769 :
770 : repeat:
771 15 : if (dev->power.runtime_error) {
772 : retval = -EINVAL;
773 15 : } else if (dev->power.disable_depth > 0) {
774 15 : if (dev->power.runtime_status == RPM_ACTIVE &&
775 0 : dev->power.last_status == RPM_ACTIVE)
776 : retval = 1;
777 : else
778 15 : retval = -EACCES;
779 : }
780 15 : if (retval)
781 : goto out;
782 :
783 : /*
784 : * Other scheduled or pending requests need to be canceled. Small
785 : * optimization: If an autosuspend timer is running, leave it running
786 : * rather than cancelling it now only to restart it again in the near
787 : * future.
788 : */
789 0 : dev->power.request = RPM_REQ_NONE;
790 0 : if (!dev->power.timer_autosuspends)
791 : pm_runtime_deactivate_timer(dev);
792 :
793 0 : if (dev->power.runtime_status == RPM_ACTIVE) {
794 : retval = 1;
795 : goto out;
796 : }
797 :
798 0 : if (dev->power.runtime_status == RPM_RESUMING ||
799 : dev->power.runtime_status == RPM_SUSPENDING) {
800 0 : DEFINE_WAIT(wait);
801 :
802 0 : if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
803 0 : if (dev->power.runtime_status == RPM_SUSPENDING) {
804 0 : dev->power.deferred_resume = true;
805 0 : if (rpmflags & RPM_NOWAIT)
806 0 : retval = -EINPROGRESS;
807 : } else {
808 : retval = -EINPROGRESS;
809 : }
810 0 : goto out;
811 : }
812 :
813 0 : if (dev->power.irq_safe) {
814 0 : spin_unlock(&dev->power.lock);
815 :
816 : cpu_relax();
817 :
818 0 : spin_lock(&dev->power.lock);
819 0 : goto repeat;
820 : }
821 :
822 : /* Wait for the operation carried out in parallel with us. */
823 : for (;;) {
824 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
825 : TASK_UNINTERRUPTIBLE);
826 0 : if (dev->power.runtime_status != RPM_RESUMING &&
827 : dev->power.runtime_status != RPM_SUSPENDING)
828 : break;
829 :
830 0 : spin_unlock_irq(&dev->power.lock);
831 :
832 0 : schedule();
833 :
834 0 : spin_lock_irq(&dev->power.lock);
835 : }
836 0 : finish_wait(&dev->power.wait_queue, &wait);
837 0 : goto repeat;
838 : }
839 :
840 : /*
841 : * See if we can skip waking up the parent. This is safe only if
842 : * power.no_callbacks is set, because otherwise we don't know whether
843 : * the resume will actually succeed.
844 : */
845 0 : if (dev->power.no_callbacks && !parent && dev->parent) {
846 0 : spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
847 0 : if (dev->parent->power.disable_depth > 0 ||
848 0 : dev->parent->power.ignore_children ||
849 0 : dev->parent->power.runtime_status == RPM_ACTIVE) {
850 0 : atomic_inc(&dev->parent->power.child_count);
851 0 : spin_unlock(&dev->parent->power.lock);
852 0 : retval = 1;
853 0 : goto no_callback; /* Assume success. */
854 : }
855 0 : spin_unlock(&dev->parent->power.lock);
856 : }
857 :
858 : /* Carry out an asynchronous or a synchronous resume. */
859 0 : if (rpmflags & RPM_ASYNC) {
860 0 : dev->power.request = RPM_REQ_RESUME;
861 0 : if (!dev->power.request_pending) {
862 0 : dev->power.request_pending = true;
863 0 : queue_work(pm_wq, &dev->power.work);
864 : }
865 : retval = 0;
866 : goto out;
867 : }
868 :
869 0 : if (!parent && dev->parent) {
870 : /*
871 : * Increment the parent's usage counter and resume it if
872 : * necessary. Not needed if dev is irq-safe; then the
873 : * parent is permanently resumed.
874 : */
875 0 : parent = dev->parent;
876 0 : if (dev->power.irq_safe)
877 : goto skip_parent;
878 :
879 0 : spin_unlock(&dev->power.lock);
880 :
881 0 : pm_runtime_get_noresume(parent);
882 :
883 0 : spin_lock(&parent->power.lock);
884 : /*
885 : * Resume the parent if it has runtime PM enabled and not been
886 : * set to ignore its children.
887 : */
888 0 : if (!parent->power.disable_depth &&
889 0 : !parent->power.ignore_children) {
890 0 : rpm_resume(parent, 0);
891 0 : if (parent->power.runtime_status != RPM_ACTIVE)
892 0 : retval = -EBUSY;
893 : }
894 0 : spin_unlock(&parent->power.lock);
895 :
896 0 : spin_lock(&dev->power.lock);
897 0 : if (retval)
898 : goto out;
899 :
900 : goto repeat;
901 : }
902 : skip_parent:
903 :
904 0 : if (dev->power.no_callbacks)
905 : goto no_callback; /* Assume success. */
906 :
907 0 : __update_runtime_status(dev, RPM_RESUMING);
908 :
909 0 : callback = RPM_GET_CALLBACK(dev, runtime_resume);
910 :
911 0 : dev_pm_disable_wake_irq_check(dev, false);
912 0 : retval = rpm_callback(callback, dev);
913 0 : if (retval) {
914 0 : __update_runtime_status(dev, RPM_SUSPENDED);
915 0 : pm_runtime_cancel_pending(dev);
916 0 : dev_pm_enable_wake_irq_check(dev, false);
917 : } else {
918 : no_callback:
919 0 : __update_runtime_status(dev, RPM_ACTIVE);
920 0 : pm_runtime_mark_last_busy(dev);
921 0 : if (parent)
922 0 : atomic_inc(&parent->power.child_count);
923 : }
924 0 : wake_up_all(&dev->power.wait_queue);
925 :
926 0 : if (retval >= 0)
927 0 : rpm_idle(dev, RPM_ASYNC);
928 :
929 : out:
930 15 : if (parent && !dev->power.irq_safe) {
931 0 : spin_unlock_irq(&dev->power.lock);
932 :
933 0 : pm_runtime_put(parent);
934 :
935 0 : spin_lock_irq(&dev->power.lock);
936 : }
937 :
938 15 : trace_rpm_return_int(dev, _THIS_IP_, retval);
939 :
940 15 : return retval;
941 : }
942 :
943 : /**
944 : * pm_runtime_work - Universal runtime PM work function.
945 : * @work: Work structure used for scheduling the execution of this function.
946 : *
947 : * Use @work to get the device object the work is to be done for, determine what
948 : * is to be done and execute the appropriate runtime PM function.
949 : */
950 0 : static void pm_runtime_work(struct work_struct *work)
951 : {
952 0 : struct device *dev = container_of(work, struct device, power.work);
953 : enum rpm_request req;
954 :
955 0 : spin_lock_irq(&dev->power.lock);
956 :
957 0 : if (!dev->power.request_pending)
958 : goto out;
959 :
960 0 : req = dev->power.request;
961 0 : dev->power.request = RPM_REQ_NONE;
962 0 : dev->power.request_pending = false;
963 :
964 0 : switch (req) {
965 : case RPM_REQ_NONE:
966 : break;
967 : case RPM_REQ_IDLE:
968 0 : rpm_idle(dev, RPM_NOWAIT);
969 0 : break;
970 : case RPM_REQ_SUSPEND:
971 0 : rpm_suspend(dev, RPM_NOWAIT);
972 0 : break;
973 : case RPM_REQ_AUTOSUSPEND:
974 0 : rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
975 0 : break;
976 : case RPM_REQ_RESUME:
977 0 : rpm_resume(dev, RPM_NOWAIT);
978 0 : break;
979 : }
980 :
981 : out:
982 0 : spin_unlock_irq(&dev->power.lock);
983 0 : }
984 :
985 : /**
986 : * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
987 : * @timer: hrtimer used by pm_schedule_suspend().
988 : *
989 : * Check if the time is right and queue a suspend request.
990 : */
991 0 : static enum hrtimer_restart pm_suspend_timer_fn(struct hrtimer *timer)
992 : {
993 0 : struct device *dev = container_of(timer, struct device, power.suspend_timer);
994 : unsigned long flags;
995 : u64 expires;
996 :
997 0 : spin_lock_irqsave(&dev->power.lock, flags);
998 :
999 0 : expires = dev->power.timer_expires;
1000 : /*
1001 : * If 'expires' is after the current time, we've been called
1002 : * too early.
1003 : */
1004 0 : if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
1005 0 : dev->power.timer_expires = 0;
1006 0 : rpm_suspend(dev, dev->power.timer_autosuspends ?
1007 : (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
1008 : }
1009 :
1010 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1011 :
1012 0 : return HRTIMER_NORESTART;
1013 : }
1014 :
1015 : /**
1016 : * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
1017 : * @dev: Device to suspend.
1018 : * @delay: Time to wait before submitting a suspend request, in milliseconds.
1019 : */
1020 0 : int pm_schedule_suspend(struct device *dev, unsigned int delay)
1021 : {
1022 : unsigned long flags;
1023 : u64 expires;
1024 : int retval;
1025 :
1026 0 : spin_lock_irqsave(&dev->power.lock, flags);
1027 :
1028 0 : if (!delay) {
1029 0 : retval = rpm_suspend(dev, RPM_ASYNC);
1030 0 : goto out;
1031 : }
1032 :
1033 0 : retval = rpm_check_suspend_allowed(dev);
1034 0 : if (retval)
1035 : goto out;
1036 :
1037 : /* Other scheduled or pending requests need to be canceled. */
1038 0 : pm_runtime_cancel_pending(dev);
1039 :
1040 0 : expires = ktime_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC;
1041 0 : dev->power.timer_expires = expires;
1042 0 : dev->power.timer_autosuspends = 0;
1043 0 : hrtimer_start(&dev->power.suspend_timer, expires, HRTIMER_MODE_ABS);
1044 :
1045 : out:
1046 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1047 :
1048 0 : return retval;
1049 : }
1050 : EXPORT_SYMBOL_GPL(pm_schedule_suspend);
1051 :
1052 : static int rpm_drop_usage_count(struct device *dev)
1053 : {
1054 : int ret;
1055 :
1056 30 : ret = atomic_sub_return(1, &dev->power.usage_count);
1057 15 : if (ret >= 0)
1058 : return ret;
1059 :
1060 : /*
1061 : * Because rpm_resume() does not check the usage counter, it will resume
1062 : * the device even if the usage counter is 0 or negative, so it is
1063 : * sufficient to increment the usage counter here to reverse the change
1064 : * made above.
1065 : */
1066 0 : atomic_inc(&dev->power.usage_count);
1067 0 : dev_warn(dev, "Runtime PM usage count underflow!\n");
1068 : return -EINVAL;
1069 : }
1070 :
1071 : /**
1072 : * __pm_runtime_idle - Entry point for runtime idle operations.
1073 : * @dev: Device to send idle notification for.
1074 : * @rpmflags: Flag bits.
1075 : *
1076 : * If the RPM_GET_PUT flag is set, decrement the device's usage count and
1077 : * return immediately if it is larger than zero (if it becomes negative, log a
1078 : * warning, increment it, and return an error). Then carry out an idle
1079 : * notification, either synchronous or asynchronous.
1080 : *
1081 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1082 : * or if pm_runtime_irq_safe() has been called.
1083 : */
1084 29 : int __pm_runtime_idle(struct device *dev, int rpmflags)
1085 : {
1086 : unsigned long flags;
1087 : int retval;
1088 :
1089 29 : if (rpmflags & RPM_GET_PUT) {
1090 15 : retval = rpm_drop_usage_count(dev);
1091 15 : if (retval < 0) {
1092 : return retval;
1093 15 : } else if (retval > 0) {
1094 : trace_rpm_usage(dev, rpmflags);
1095 : return 0;
1096 : }
1097 : }
1098 :
1099 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
1100 :
1101 24 : spin_lock_irqsave(&dev->power.lock, flags);
1102 24 : retval = rpm_idle(dev, rpmflags);
1103 48 : spin_unlock_irqrestore(&dev->power.lock, flags);
1104 :
1105 24 : return retval;
1106 : }
1107 : EXPORT_SYMBOL_GPL(__pm_runtime_idle);
1108 :
1109 : /**
1110 : * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
1111 : * @dev: Device to suspend.
1112 : * @rpmflags: Flag bits.
1113 : *
1114 : * If the RPM_GET_PUT flag is set, decrement the device's usage count and
1115 : * return immediately if it is larger than zero (if it becomes negative, log a
1116 : * warning, increment it, and return an error). Then carry out a suspend,
1117 : * either synchronous or asynchronous.
1118 : *
1119 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1120 : * or if pm_runtime_irq_safe() has been called.
1121 : */
1122 0 : int __pm_runtime_suspend(struct device *dev, int rpmflags)
1123 : {
1124 : unsigned long flags;
1125 : int retval;
1126 :
1127 0 : if (rpmflags & RPM_GET_PUT) {
1128 0 : retval = rpm_drop_usage_count(dev);
1129 0 : if (retval < 0) {
1130 : return retval;
1131 0 : } else if (retval > 0) {
1132 : trace_rpm_usage(dev, rpmflags);
1133 : return 0;
1134 : }
1135 : }
1136 :
1137 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
1138 :
1139 0 : spin_lock_irqsave(&dev->power.lock, flags);
1140 0 : retval = rpm_suspend(dev, rpmflags);
1141 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1142 :
1143 0 : return retval;
1144 : }
1145 : EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
1146 :
1147 : /**
1148 : * __pm_runtime_resume - Entry point for runtime resume operations.
1149 : * @dev: Device to resume.
1150 : * @rpmflags: Flag bits.
1151 : *
1152 : * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
1153 : * carry out a resume, either synchronous or asynchronous.
1154 : *
1155 : * This routine may be called in atomic context if the RPM_ASYNC flag is set,
1156 : * or if pm_runtime_irq_safe() has been called.
1157 : */
1158 15 : int __pm_runtime_resume(struct device *dev, int rpmflags)
1159 : {
1160 : unsigned long flags;
1161 : int retval;
1162 :
1163 : might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
1164 : dev->power.runtime_status != RPM_ACTIVE);
1165 :
1166 15 : if (rpmflags & RPM_GET_PUT)
1167 15 : atomic_inc(&dev->power.usage_count);
1168 :
1169 15 : spin_lock_irqsave(&dev->power.lock, flags);
1170 15 : retval = rpm_resume(dev, rpmflags);
1171 30 : spin_unlock_irqrestore(&dev->power.lock, flags);
1172 :
1173 15 : return retval;
1174 : }
1175 : EXPORT_SYMBOL_GPL(__pm_runtime_resume);
1176 :
1177 : /**
1178 : * pm_runtime_get_if_active - Conditionally bump up device usage counter.
1179 : * @dev: Device to handle.
1180 : * @ign_usage_count: Whether or not to look at the current usage counter value.
1181 : *
1182 : * Return -EINVAL if runtime PM is disabled for @dev.
1183 : *
1184 : * Otherwise, if the runtime PM status of @dev is %RPM_ACTIVE and either
1185 : * @ign_usage_count is %true or the runtime PM usage counter of @dev is not
1186 : * zero, increment the usage counter of @dev and return 1. Otherwise, return 0
1187 : * without changing the usage counter.
1188 : *
1189 : * If @ign_usage_count is %true, this function can be used to prevent suspending
1190 : * the device when its runtime PM status is %RPM_ACTIVE.
1191 : *
1192 : * If @ign_usage_count is %false, this function can be used to prevent
1193 : * suspending the device when both its runtime PM status is %RPM_ACTIVE and its
1194 : * runtime PM usage counter is not zero.
1195 : *
1196 : * The caller is responsible for decrementing the runtime PM usage counter of
1197 : * @dev after this function has returned a positive value for it.
1198 : */
1199 0 : int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
1200 : {
1201 : unsigned long flags;
1202 : int retval;
1203 :
1204 0 : spin_lock_irqsave(&dev->power.lock, flags);
1205 0 : if (dev->power.disable_depth > 0) {
1206 : retval = -EINVAL;
1207 0 : } else if (dev->power.runtime_status != RPM_ACTIVE) {
1208 : retval = 0;
1209 0 : } else if (ign_usage_count) {
1210 0 : retval = 1;
1211 0 : atomic_inc(&dev->power.usage_count);
1212 : } else {
1213 0 : retval = atomic_inc_not_zero(&dev->power.usage_count);
1214 : }
1215 0 : trace_rpm_usage(dev, 0);
1216 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1217 :
1218 0 : return retval;
1219 : }
1220 : EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);
1221 :
1222 : /**
1223 : * __pm_runtime_set_status - Set runtime PM status of a device.
1224 : * @dev: Device to handle.
1225 : * @status: New runtime PM status of the device.
1226 : *
1227 : * If runtime PM of the device is disabled or its power.runtime_error field is
1228 : * different from zero, the status may be changed either to RPM_ACTIVE, or to
1229 : * RPM_SUSPENDED, as long as that reflects the actual state of the device.
1230 : * However, if the device has a parent and the parent is not active, and the
1231 : * parent's power.ignore_children flag is unset, the device's status cannot be
1232 : * set to RPM_ACTIVE, so -EBUSY is returned in that case.
1233 : *
1234 : * If successful, __pm_runtime_set_status() clears the power.runtime_error field
1235 : * and the device parent's counter of unsuspended children is modified to
1236 : * reflect the new status. If the new status is RPM_SUSPENDED, an idle
1237 : * notification request for the parent is submitted.
1238 : *
1239 : * If @dev has any suppliers (as reflected by device links to them), and @status
1240 : * is RPM_ACTIVE, they will be activated upfront and if the activation of one
1241 : * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead
1242 : * of the @status value) and the suppliers will be deacticated on exit. The
1243 : * error returned by the failing supplier activation will be returned in that
1244 : * case.
1245 : */
1246 0 : int __pm_runtime_set_status(struct device *dev, unsigned int status)
1247 : {
1248 0 : struct device *parent = dev->parent;
1249 0 : bool notify_parent = false;
1250 : unsigned long flags;
1251 0 : int error = 0;
1252 :
1253 0 : if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
1254 : return -EINVAL;
1255 :
1256 0 : spin_lock_irqsave(&dev->power.lock, flags);
1257 :
1258 : /*
1259 : * Prevent PM-runtime from being enabled for the device or return an
1260 : * error if it is enabled already and working.
1261 : */
1262 0 : if (dev->power.runtime_error || dev->power.disable_depth)
1263 0 : dev->power.disable_depth++;
1264 : else
1265 : error = -EAGAIN;
1266 :
1267 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1268 :
1269 0 : if (error)
1270 : return error;
1271 :
1272 : /*
1273 : * If the new status is RPM_ACTIVE, the suppliers can be activated
1274 : * upfront regardless of the current status, because next time
1275 : * rpm_put_suppliers() runs, the rpm_active refcounts of the links
1276 : * involved will be dropped down to one anyway.
1277 : */
1278 0 : if (status == RPM_ACTIVE) {
1279 0 : int idx = device_links_read_lock();
1280 :
1281 0 : error = rpm_get_suppliers(dev);
1282 0 : if (error)
1283 0 : status = RPM_SUSPENDED;
1284 :
1285 0 : device_links_read_unlock(idx);
1286 : }
1287 :
1288 0 : spin_lock_irqsave(&dev->power.lock, flags);
1289 :
1290 0 : if (dev->power.runtime_status == status || !parent)
1291 : goto out_set;
1292 :
1293 0 : if (status == RPM_SUSPENDED) {
1294 0 : atomic_add_unless(&parent->power.child_count, -1, 0);
1295 0 : notify_parent = !parent->power.ignore_children;
1296 : } else {
1297 0 : spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
1298 :
1299 : /*
1300 : * It is invalid to put an active child under a parent that is
1301 : * not active, has runtime PM enabled and the
1302 : * 'power.ignore_children' flag unset.
1303 : */
1304 0 : if (!parent->power.disable_depth &&
1305 0 : !parent->power.ignore_children &&
1306 0 : parent->power.runtime_status != RPM_ACTIVE) {
1307 0 : dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
1308 : dev_name(dev),
1309 : dev_name(parent));
1310 0 : error = -EBUSY;
1311 0 : } else if (dev->power.runtime_status == RPM_SUSPENDED) {
1312 0 : atomic_inc(&parent->power.child_count);
1313 : }
1314 :
1315 0 : spin_unlock(&parent->power.lock);
1316 :
1317 0 : if (error) {
1318 : status = RPM_SUSPENDED;
1319 : goto out;
1320 : }
1321 : }
1322 :
1323 : out_set:
1324 0 : __update_runtime_status(dev, status);
1325 0 : if (!error)
1326 0 : dev->power.runtime_error = 0;
1327 :
1328 : out:
1329 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1330 :
1331 0 : if (notify_parent)
1332 : pm_request_idle(parent);
1333 :
1334 0 : if (status == RPM_SUSPENDED) {
1335 0 : int idx = device_links_read_lock();
1336 :
1337 0 : rpm_put_suppliers(dev);
1338 :
1339 0 : device_links_read_unlock(idx);
1340 : }
1341 :
1342 0 : pm_runtime_enable(dev);
1343 :
1344 0 : return error;
1345 : }
1346 : EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
1347 :
1348 : /**
1349 : * __pm_runtime_barrier - Cancel pending requests and wait for completions.
1350 : * @dev: Device to handle.
1351 : *
1352 : * Flush all pending requests for the device from pm_wq and wait for all
1353 : * runtime PM operations involving the device in progress to complete.
1354 : *
1355 : * Should be called under dev->power.lock with interrupts disabled.
1356 : */
1357 540 : static void __pm_runtime_barrier(struct device *dev)
1358 : {
1359 540 : pm_runtime_deactivate_timer(dev);
1360 :
1361 540 : if (dev->power.request_pending) {
1362 0 : dev->power.request = RPM_REQ_NONE;
1363 0 : spin_unlock_irq(&dev->power.lock);
1364 :
1365 0 : cancel_work_sync(&dev->power.work);
1366 :
1367 0 : spin_lock_irq(&dev->power.lock);
1368 0 : dev->power.request_pending = false;
1369 : }
1370 :
1371 540 : if (dev->power.runtime_status == RPM_SUSPENDING ||
1372 540 : dev->power.runtime_status == RPM_RESUMING ||
1373 : dev->power.idle_notification) {
1374 0 : DEFINE_WAIT(wait);
1375 :
1376 : /* Suspend, wake-up or idle notification in progress. */
1377 : for (;;) {
1378 0 : prepare_to_wait(&dev->power.wait_queue, &wait,
1379 : TASK_UNINTERRUPTIBLE);
1380 0 : if (dev->power.runtime_status != RPM_SUSPENDING
1381 0 : && dev->power.runtime_status != RPM_RESUMING
1382 0 : && !dev->power.idle_notification)
1383 : break;
1384 0 : spin_unlock_irq(&dev->power.lock);
1385 :
1386 0 : schedule();
1387 :
1388 0 : spin_lock_irq(&dev->power.lock);
1389 : }
1390 0 : finish_wait(&dev->power.wait_queue, &wait);
1391 : }
1392 540 : }
1393 :
1394 : /**
1395 : * pm_runtime_barrier - Flush pending requests and wait for completions.
1396 : * @dev: Device to handle.
1397 : *
1398 : * Prevent the device from being suspended by incrementing its usage counter and
1399 : * if there's a pending resume request for the device, wake the device up.
1400 : * Next, make sure that all pending requests for the device have been flushed
1401 : * from pm_wq and wait for all runtime PM operations involving the device in
1402 : * progress to complete.
1403 : *
1404 : * Return value:
1405 : * 1, if there was a resume request pending and the device had to be woken up,
1406 : * 0, otherwise
1407 : */
1408 540 : int pm_runtime_barrier(struct device *dev)
1409 : {
1410 540 : int retval = 0;
1411 :
1412 540 : pm_runtime_get_noresume(dev);
1413 1080 : spin_lock_irq(&dev->power.lock);
1414 :
1415 540 : if (dev->power.request_pending
1416 0 : && dev->power.request == RPM_REQ_RESUME) {
1417 0 : rpm_resume(dev, 0);
1418 0 : retval = 1;
1419 : }
1420 :
1421 540 : __pm_runtime_barrier(dev);
1422 :
1423 1080 : spin_unlock_irq(&dev->power.lock);
1424 540 : pm_runtime_put_noidle(dev);
1425 :
1426 540 : return retval;
1427 : }
1428 : EXPORT_SYMBOL_GPL(pm_runtime_barrier);
1429 :
1430 : /**
1431 : * __pm_runtime_disable - Disable runtime PM of a device.
1432 : * @dev: Device to handle.
1433 : * @check_resume: If set, check if there's a resume request for the device.
1434 : *
1435 : * Increment power.disable_depth for the device and if it was zero previously,
1436 : * cancel all pending runtime PM requests for the device and wait for all
1437 : * operations in progress to complete. The device can be either active or
1438 : * suspended after its runtime PM has been disabled.
1439 : *
1440 : * If @check_resume is set and there's a resume request pending when
1441 : * __pm_runtime_disable() is called and power.disable_depth is zero, the
1442 : * function will wake up the device before disabling its runtime PM.
1443 : */
1444 5 : void __pm_runtime_disable(struct device *dev, bool check_resume)
1445 : {
1446 10 : spin_lock_irq(&dev->power.lock);
1447 :
1448 5 : if (dev->power.disable_depth > 0) {
1449 5 : dev->power.disable_depth++;
1450 5 : goto out;
1451 : }
1452 :
1453 : /*
1454 : * Wake up the device if there's a resume request pending, because that
1455 : * means there probably is some I/O to process and disabling runtime PM
1456 : * shouldn't prevent the device from processing the I/O.
1457 : */
1458 0 : if (check_resume && dev->power.request_pending &&
1459 0 : dev->power.request == RPM_REQ_RESUME) {
1460 : /*
1461 : * Prevent suspends and idle notifications from being carried
1462 : * out after we have woken up the device.
1463 : */
1464 0 : pm_runtime_get_noresume(dev);
1465 :
1466 0 : rpm_resume(dev, 0);
1467 :
1468 : pm_runtime_put_noidle(dev);
1469 : }
1470 :
1471 : /* Update time accounting before disabling PM-runtime. */
1472 0 : update_pm_runtime_accounting(dev);
1473 :
1474 0 : if (!dev->power.disable_depth++) {
1475 0 : __pm_runtime_barrier(dev);
1476 0 : dev->power.last_status = dev->power.runtime_status;
1477 : }
1478 :
1479 : out:
1480 10 : spin_unlock_irq(&dev->power.lock);
1481 5 : }
1482 : EXPORT_SYMBOL_GPL(__pm_runtime_disable);
1483 :
1484 : /**
1485 : * pm_runtime_enable - Enable runtime PM of a device.
1486 : * @dev: Device to handle.
1487 : */
1488 0 : void pm_runtime_enable(struct device *dev)
1489 : {
1490 : unsigned long flags;
1491 :
1492 0 : spin_lock_irqsave(&dev->power.lock, flags);
1493 :
1494 0 : if (!dev->power.disable_depth) {
1495 0 : dev_warn(dev, "Unbalanced %s!\n", __func__);
1496 0 : goto out;
1497 : }
1498 :
1499 0 : if (--dev->power.disable_depth > 0)
1500 : goto out;
1501 :
1502 0 : dev->power.last_status = RPM_INVALID;
1503 0 : dev->power.accounting_timestamp = ktime_get_mono_fast_ns();
1504 :
1505 0 : if (dev->power.runtime_status == RPM_SUSPENDED &&
1506 0 : !dev->power.ignore_children &&
1507 0 : atomic_read(&dev->power.child_count) > 0)
1508 0 : dev_warn(dev, "Enabling runtime PM for inactive device with active children\n");
1509 :
1510 : out:
1511 0 : spin_unlock_irqrestore(&dev->power.lock, flags);
1512 0 : }
1513 : EXPORT_SYMBOL_GPL(pm_runtime_enable);
1514 :
1515 0 : static void pm_runtime_disable_action(void *data)
1516 : {
1517 0 : pm_runtime_dont_use_autosuspend(data);
1518 0 : pm_runtime_disable(data);
1519 0 : }
1520 :
1521 : /**
1522 : * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.
1523 : *
1524 : * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for
1525 : * you at driver exit time if needed.
1526 : *
1527 : * @dev: Device to handle.
1528 : */
1529 0 : int devm_pm_runtime_enable(struct device *dev)
1530 : {
1531 0 : pm_runtime_enable(dev);
1532 :
1533 0 : return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);
1534 : }
1535 : EXPORT_SYMBOL_GPL(devm_pm_runtime_enable);
1536 :
1537 : /**
1538 : * pm_runtime_forbid - Block runtime PM of a device.
1539 : * @dev: Device to handle.
1540 : *
1541 : * Increase the device's usage count and clear its power.runtime_auto flag,
1542 : * so that it cannot be suspended at run time until pm_runtime_allow() is called
1543 : * for it.
1544 : */
1545 0 : void pm_runtime_forbid(struct device *dev)
1546 : {
1547 0 : spin_lock_irq(&dev->power.lock);
1548 0 : if (!dev->power.runtime_auto)
1549 : goto out;
1550 :
1551 0 : dev->power.runtime_auto = false;
1552 0 : atomic_inc(&dev->power.usage_count);
1553 0 : rpm_resume(dev, 0);
1554 :
1555 : out:
1556 0 : spin_unlock_irq(&dev->power.lock);
1557 0 : }
1558 : EXPORT_SYMBOL_GPL(pm_runtime_forbid);
1559 :
1560 : /**
1561 : * pm_runtime_allow - Unblock runtime PM of a device.
1562 : * @dev: Device to handle.
1563 : *
1564 : * Decrease the device's usage count and set its power.runtime_auto flag.
1565 : */
1566 0 : void pm_runtime_allow(struct device *dev)
1567 : {
1568 : int ret;
1569 :
1570 0 : spin_lock_irq(&dev->power.lock);
1571 0 : if (dev->power.runtime_auto)
1572 : goto out;
1573 :
1574 0 : dev->power.runtime_auto = true;
1575 0 : ret = rpm_drop_usage_count(dev);
1576 0 : if (ret == 0)
1577 0 : rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
1578 : else if (ret > 0)
1579 : trace_rpm_usage(dev, RPM_AUTO | RPM_ASYNC);
1580 :
1581 : out:
1582 0 : spin_unlock_irq(&dev->power.lock);
1583 0 : }
1584 : EXPORT_SYMBOL_GPL(pm_runtime_allow);
1585 :
1586 : /**
1587 : * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
1588 : * @dev: Device to handle.
1589 : *
1590 : * Set the power.no_callbacks flag, which tells the PM core that this
1591 : * device is power-managed through its parent and has no runtime PM
1592 : * callbacks of its own. The runtime sysfs attributes will be removed.
1593 : */
1594 0 : void pm_runtime_no_callbacks(struct device *dev)
1595 : {
1596 0 : spin_lock_irq(&dev->power.lock);
1597 0 : dev->power.no_callbacks = 1;
1598 0 : spin_unlock_irq(&dev->power.lock);
1599 0 : if (device_is_registered(dev))
1600 0 : rpm_sysfs_remove(dev);
1601 0 : }
1602 : EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
1603 :
1604 : /**
1605 : * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
1606 : * @dev: Device to handle
1607 : *
1608 : * Set the power.irq_safe flag, which tells the PM core that the
1609 : * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
1610 : * always be invoked with the spinlock held and interrupts disabled. It also
1611 : * causes the parent's usage counter to be permanently incremented, preventing
1612 : * the parent from runtime suspending -- otherwise an irq-safe child might have
1613 : * to wait for a non-irq-safe parent.
1614 : */
1615 0 : void pm_runtime_irq_safe(struct device *dev)
1616 : {
1617 0 : if (dev->parent)
1618 0 : pm_runtime_get_sync(dev->parent);
1619 :
1620 0 : spin_lock_irq(&dev->power.lock);
1621 0 : dev->power.irq_safe = 1;
1622 0 : spin_unlock_irq(&dev->power.lock);
1623 0 : }
1624 : EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
1625 :
1626 : /**
1627 : * update_autosuspend - Handle a change to a device's autosuspend settings.
1628 : * @dev: Device to handle.
1629 : * @old_delay: The former autosuspend_delay value.
1630 : * @old_use: The former use_autosuspend value.
1631 : *
1632 : * Prevent runtime suspend if the new delay is negative and use_autosuspend is
1633 : * set; otherwise allow it. Send an idle notification if suspends are allowed.
1634 : *
1635 : * This function must be called under dev->power.lock with interrupts disabled.
1636 : */
1637 0 : static void update_autosuspend(struct device *dev, int old_delay, int old_use)
1638 : {
1639 0 : int delay = dev->power.autosuspend_delay;
1640 :
1641 : /* Should runtime suspend be prevented now? */
1642 0 : if (dev->power.use_autosuspend && delay < 0) {
1643 :
1644 : /* If it used to be allowed then prevent it. */
1645 0 : if (!old_use || old_delay >= 0) {
1646 0 : atomic_inc(&dev->power.usage_count);
1647 0 : rpm_resume(dev, 0);
1648 : } else {
1649 : trace_rpm_usage(dev, 0);
1650 : }
1651 : }
1652 :
1653 : /* Runtime suspend should be allowed now. */
1654 : else {
1655 :
1656 : /* If it used to be prevented then allow it. */
1657 0 : if (old_use && old_delay < 0)
1658 0 : atomic_dec(&dev->power.usage_count);
1659 :
1660 : /* Maybe we can autosuspend now. */
1661 0 : rpm_idle(dev, RPM_AUTO);
1662 : }
1663 0 : }
1664 :
1665 : /**
1666 : * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
1667 : * @dev: Device to handle.
1668 : * @delay: Value of the new delay in milliseconds.
1669 : *
1670 : * Set the device's power.autosuspend_delay value. If it changes to negative
1671 : * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
1672 : * changes the other way, allow runtime suspends.
1673 : */
1674 0 : void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
1675 : {
1676 : int old_delay, old_use;
1677 :
1678 0 : spin_lock_irq(&dev->power.lock);
1679 0 : old_delay = dev->power.autosuspend_delay;
1680 0 : old_use = dev->power.use_autosuspend;
1681 0 : dev->power.autosuspend_delay = delay;
1682 0 : update_autosuspend(dev, old_delay, old_use);
1683 0 : spin_unlock_irq(&dev->power.lock);
1684 0 : }
1685 : EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
1686 :
1687 : /**
1688 : * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
1689 : * @dev: Device to handle.
1690 : * @use: New value for use_autosuspend.
1691 : *
1692 : * Set the device's power.use_autosuspend flag, and allow or prevent runtime
1693 : * suspends as needed.
1694 : */
1695 0 : void __pm_runtime_use_autosuspend(struct device *dev, bool use)
1696 : {
1697 : int old_delay, old_use;
1698 :
1699 0 : spin_lock_irq(&dev->power.lock);
1700 0 : old_delay = dev->power.autosuspend_delay;
1701 0 : old_use = dev->power.use_autosuspend;
1702 0 : dev->power.use_autosuspend = use;
1703 0 : update_autosuspend(dev, old_delay, old_use);
1704 0 : spin_unlock_irq(&dev->power.lock);
1705 0 : }
1706 : EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
1707 :
1708 : /**
1709 : * pm_runtime_init - Initialize runtime PM fields in given device object.
1710 : * @dev: Device object to initialize.
1711 : */
1712 545 : void pm_runtime_init(struct device *dev)
1713 : {
1714 545 : dev->power.runtime_status = RPM_SUSPENDED;
1715 545 : dev->power.last_status = RPM_INVALID;
1716 545 : dev->power.idle_notification = false;
1717 :
1718 545 : dev->power.disable_depth = 1;
1719 1090 : atomic_set(&dev->power.usage_count, 0);
1720 :
1721 545 : dev->power.runtime_error = 0;
1722 :
1723 1090 : atomic_set(&dev->power.child_count, 0);
1724 545 : pm_suspend_ignore_children(dev, false);
1725 545 : dev->power.runtime_auto = true;
1726 :
1727 545 : dev->power.request_pending = false;
1728 545 : dev->power.request = RPM_REQ_NONE;
1729 545 : dev->power.deferred_resume = false;
1730 545 : dev->power.needs_force_resume = 0;
1731 1090 : INIT_WORK(&dev->power.work, pm_runtime_work);
1732 :
1733 545 : dev->power.timer_expires = 0;
1734 545 : hrtimer_init(&dev->power.suspend_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1735 545 : dev->power.suspend_timer.function = pm_suspend_timer_fn;
1736 :
1737 545 : init_waitqueue_head(&dev->power.wait_queue);
1738 545 : }
1739 :
1740 : /**
1741 : * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
1742 : * @dev: Device object to re-initialize.
1743 : */
1744 10 : void pm_runtime_reinit(struct device *dev)
1745 : {
1746 10 : if (!pm_runtime_enabled(dev)) {
1747 10 : if (dev->power.runtime_status == RPM_ACTIVE)
1748 : pm_runtime_set_suspended(dev);
1749 10 : if (dev->power.irq_safe) {
1750 0 : spin_lock_irq(&dev->power.lock);
1751 0 : dev->power.irq_safe = 0;
1752 0 : spin_unlock_irq(&dev->power.lock);
1753 0 : if (dev->parent)
1754 0 : pm_runtime_put(dev->parent);
1755 : }
1756 : }
1757 10 : }
1758 :
1759 : /**
1760 : * pm_runtime_remove - Prepare for removing a device from device hierarchy.
1761 : * @dev: Device object being removed from device hierarchy.
1762 : */
1763 5 : void pm_runtime_remove(struct device *dev)
1764 : {
1765 5 : __pm_runtime_disable(dev, false);
1766 5 : pm_runtime_reinit(dev);
1767 5 : }
1768 :
1769 : /**
1770 : * pm_runtime_get_suppliers - Resume and reference-count supplier devices.
1771 : * @dev: Consumer device.
1772 : */
1773 5 : void pm_runtime_get_suppliers(struct device *dev)
1774 : {
1775 : struct device_link *link;
1776 : int idx;
1777 :
1778 5 : idx = device_links_read_lock();
1779 :
1780 5 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
1781 : device_links_read_lock_held())
1782 0 : if (link->flags & DL_FLAG_PM_RUNTIME) {
1783 0 : link->supplier_preactivated = true;
1784 0 : pm_runtime_get_sync(link->supplier);
1785 : }
1786 :
1787 5 : device_links_read_unlock(idx);
1788 5 : }
1789 :
1790 : /**
1791 : * pm_runtime_put_suppliers - Drop references to supplier devices.
1792 : * @dev: Consumer device.
1793 : */
1794 5 : void pm_runtime_put_suppliers(struct device *dev)
1795 : {
1796 : struct device_link *link;
1797 : int idx;
1798 :
1799 5 : idx = device_links_read_lock();
1800 :
1801 5 : list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
1802 : device_links_read_lock_held())
1803 0 : if (link->supplier_preactivated) {
1804 0 : link->supplier_preactivated = false;
1805 0 : pm_runtime_put(link->supplier);
1806 : }
1807 :
1808 5 : device_links_read_unlock(idx);
1809 5 : }
1810 :
1811 0 : void pm_runtime_new_link(struct device *dev)
1812 : {
1813 0 : spin_lock_irq(&dev->power.lock);
1814 0 : dev->power.links_count++;
1815 0 : spin_unlock_irq(&dev->power.lock);
1816 0 : }
1817 :
1818 0 : static void pm_runtime_drop_link_count(struct device *dev)
1819 : {
1820 0 : spin_lock_irq(&dev->power.lock);
1821 0 : WARN_ON(dev->power.links_count == 0);
1822 0 : dev->power.links_count--;
1823 0 : spin_unlock_irq(&dev->power.lock);
1824 0 : }
1825 :
1826 : /**
1827 : * pm_runtime_drop_link - Prepare for device link removal.
1828 : * @link: Device link going away.
1829 : *
1830 : * Drop the link count of the consumer end of @link and decrement the supplier
1831 : * device's runtime PM usage counter as many times as needed to drop all of the
1832 : * PM runtime reference to it from the consumer.
1833 : */
1834 0 : void pm_runtime_drop_link(struct device_link *link)
1835 : {
1836 0 : if (!(link->flags & DL_FLAG_PM_RUNTIME))
1837 : return;
1838 :
1839 0 : pm_runtime_drop_link_count(link->consumer);
1840 0 : pm_runtime_release_supplier(link);
1841 0 : pm_request_idle(link->supplier);
1842 : }
1843 :
1844 : static bool pm_runtime_need_not_resume(struct device *dev)
1845 : {
1846 0 : return atomic_read(&dev->power.usage_count) <= 1 &&
1847 0 : (atomic_read(&dev->power.child_count) == 0 ||
1848 : dev->power.ignore_children);
1849 : }
1850 :
1851 : /**
1852 : * pm_runtime_force_suspend - Force a device into suspend state if needed.
1853 : * @dev: Device to suspend.
1854 : *
1855 : * Disable runtime PM so we safely can check the device's runtime PM status and
1856 : * if it is active, invoke its ->runtime_suspend callback to suspend it and
1857 : * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's
1858 : * usage and children counters don't indicate that the device was in use before
1859 : * the system-wide transition under way, decrement its parent's children counter
1860 : * (if there is a parent). Keep runtime PM disabled to preserve the state
1861 : * unless we encounter errors.
1862 : *
1863 : * Typically this function may be invoked from a system suspend callback to make
1864 : * sure the device is put into low power state and it should only be used during
1865 : * system-wide PM transitions to sleep states. It assumes that the analogous
1866 : * pm_runtime_force_resume() will be used to resume the device.
1867 : *
1868 : * Do not use with DPM_FLAG_SMART_SUSPEND as this can lead to an inconsistent
1869 : * state where this function has called the ->runtime_suspend callback but the
1870 : * PM core marks the driver as runtime active.
1871 : */
1872 0 : int pm_runtime_force_suspend(struct device *dev)
1873 : {
1874 : int (*callback)(struct device *);
1875 : int ret;
1876 :
1877 0 : pm_runtime_disable(dev);
1878 0 : if (pm_runtime_status_suspended(dev))
1879 : return 0;
1880 :
1881 0 : callback = RPM_GET_CALLBACK(dev, runtime_suspend);
1882 :
1883 0 : dev_pm_enable_wake_irq_check(dev, true);
1884 0 : ret = callback ? callback(dev) : 0;
1885 0 : if (ret)
1886 : goto err;
1887 :
1888 0 : dev_pm_enable_wake_irq_complete(dev);
1889 :
1890 : /*
1891 : * If the device can stay in suspend after the system-wide transition
1892 : * to the working state that will follow, drop the children counter of
1893 : * its parent, but set its status to RPM_SUSPENDED anyway in case this
1894 : * function will be called again for it in the meantime.
1895 : */
1896 0 : if (pm_runtime_need_not_resume(dev)) {
1897 : pm_runtime_set_suspended(dev);
1898 : } else {
1899 0 : __update_runtime_status(dev, RPM_SUSPENDED);
1900 0 : dev->power.needs_force_resume = 1;
1901 : }
1902 :
1903 : return 0;
1904 :
1905 : err:
1906 0 : dev_pm_disable_wake_irq_check(dev, true);
1907 0 : pm_runtime_enable(dev);
1908 0 : return ret;
1909 : }
1910 : EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
1911 :
1912 : /**
1913 : * pm_runtime_force_resume - Force a device into resume state if needed.
1914 : * @dev: Device to resume.
1915 : *
1916 : * Prior invoking this function we expect the user to have brought the device
1917 : * into low power state by a call to pm_runtime_force_suspend(). Here we reverse
1918 : * those actions and bring the device into full power, if it is expected to be
1919 : * used on system resume. In the other case, we defer the resume to be managed
1920 : * via runtime PM.
1921 : *
1922 : * Typically this function may be invoked from a system resume callback.
1923 : */
1924 0 : int pm_runtime_force_resume(struct device *dev)
1925 : {
1926 : int (*callback)(struct device *);
1927 0 : int ret = 0;
1928 :
1929 0 : if (!pm_runtime_status_suspended(dev) || !dev->power.needs_force_resume)
1930 : goto out;
1931 :
1932 : /*
1933 : * The value of the parent's children counter is correct already, so
1934 : * just update the status of the device.
1935 : */
1936 0 : __update_runtime_status(dev, RPM_ACTIVE);
1937 :
1938 0 : callback = RPM_GET_CALLBACK(dev, runtime_resume);
1939 :
1940 0 : dev_pm_disable_wake_irq_check(dev, false);
1941 0 : ret = callback ? callback(dev) : 0;
1942 0 : if (ret) {
1943 0 : pm_runtime_set_suspended(dev);
1944 0 : dev_pm_enable_wake_irq_check(dev, false);
1945 0 : goto out;
1946 : }
1947 :
1948 : pm_runtime_mark_last_busy(dev);
1949 : out:
1950 0 : dev->power.needs_force_resume = 0;
1951 0 : pm_runtime_enable(dev);
1952 0 : return ret;
1953 : }
1954 : EXPORT_SYMBOL_GPL(pm_runtime_force_resume);
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