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