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5e928f77 RW |
1 | /* |
2 | * drivers/base/power/runtime.c - Helper functions for device run-time PM | |
3 | * | |
4 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. | |
5 | * | |
6 | * This file is released under the GPLv2. | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/pm_runtime.h> | |
11 | #include <linux/jiffies.h> | |
12 | ||
13 | static int __pm_runtime_resume(struct device *dev, bool from_wq); | |
14 | static int __pm_request_idle(struct device *dev); | |
15 | static int __pm_request_resume(struct device *dev); | |
16 | ||
17 | /** | |
18 | * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. | |
19 | * @dev: Device to handle. | |
20 | */ | |
21 | static void pm_runtime_deactivate_timer(struct device *dev) | |
22 | { | |
23 | if (dev->power.timer_expires > 0) { | |
24 | del_timer(&dev->power.suspend_timer); | |
25 | dev->power.timer_expires = 0; | |
26 | } | |
27 | } | |
28 | ||
29 | /** | |
30 | * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests. | |
31 | * @dev: Device to handle. | |
32 | */ | |
33 | static void pm_runtime_cancel_pending(struct device *dev) | |
34 | { | |
35 | pm_runtime_deactivate_timer(dev); | |
36 | /* | |
37 | * In case there's a request pending, make sure its work function will | |
38 | * return without doing anything. | |
39 | */ | |
40 | dev->power.request = RPM_REQ_NONE; | |
41 | } | |
42 | ||
43 | /** | |
44 | * __pm_runtime_idle - Notify device bus type if the device can be suspended. | |
45 | * @dev: Device to notify the bus type about. | |
46 | * | |
47 | * This function must be called under dev->power.lock with interrupts disabled. | |
48 | */ | |
49 | static int __pm_runtime_idle(struct device *dev) | |
50 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
51 | { | |
52 | int retval = 0; | |
53 | ||
5e928f77 RW |
54 | if (dev->power.runtime_error) |
55 | retval = -EINVAL; | |
56 | else if (dev->power.idle_notification) | |
57 | retval = -EINPROGRESS; | |
58 | else if (atomic_read(&dev->power.usage_count) > 0 | |
59 | || dev->power.disable_depth > 0 | |
60 | || dev->power.runtime_status != RPM_ACTIVE) | |
61 | retval = -EAGAIN; | |
62 | else if (!pm_children_suspended(dev)) | |
63 | retval = -EBUSY; | |
64 | if (retval) | |
65 | goto out; | |
66 | ||
67 | if (dev->power.request_pending) { | |
68 | /* | |
69 | * If an idle notification request is pending, cancel it. Any | |
70 | * other pending request takes precedence over us. | |
71 | */ | |
72 | if (dev->power.request == RPM_REQ_IDLE) { | |
73 | dev->power.request = RPM_REQ_NONE; | |
74 | } else if (dev->power.request != RPM_REQ_NONE) { | |
75 | retval = -EAGAIN; | |
76 | goto out; | |
77 | } | |
78 | } | |
79 | ||
80 | dev->power.idle_notification = true; | |
81 | ||
82 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) { | |
83 | spin_unlock_irq(&dev->power.lock); | |
84 | ||
85 | dev->bus->pm->runtime_idle(dev); | |
86 | ||
87 | spin_lock_irq(&dev->power.lock); | |
88 | } | |
89 | ||
90 | dev->power.idle_notification = false; | |
91 | wake_up_all(&dev->power.wait_queue); | |
92 | ||
93 | out: | |
5e928f77 RW |
94 | return retval; |
95 | } | |
96 | ||
97 | /** | |
98 | * pm_runtime_idle - Notify device bus type if the device can be suspended. | |
99 | * @dev: Device to notify the bus type about. | |
100 | */ | |
101 | int pm_runtime_idle(struct device *dev) | |
102 | { | |
103 | int retval; | |
104 | ||
105 | spin_lock_irq(&dev->power.lock); | |
106 | retval = __pm_runtime_idle(dev); | |
107 | spin_unlock_irq(&dev->power.lock); | |
108 | ||
109 | return retval; | |
110 | } | |
111 | EXPORT_SYMBOL_GPL(pm_runtime_idle); | |
112 | ||
113 | /** | |
114 | * __pm_runtime_suspend - Carry out run-time suspend of given device. | |
115 | * @dev: Device to suspend. | |
116 | * @from_wq: If set, the function has been called via pm_wq. | |
117 | * | |
118 | * Check if the device can be suspended and run the ->runtime_suspend() callback | |
119 | * provided by its bus type. If another suspend has been started earlier, wait | |
120 | * for it to finish. If an idle notification or suspend request is pending or | |
121 | * scheduled, cancel it. | |
122 | * | |
123 | * This function must be called under dev->power.lock with interrupts disabled. | |
124 | */ | |
125 | int __pm_runtime_suspend(struct device *dev, bool from_wq) | |
126 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
127 | { | |
128 | struct device *parent = NULL; | |
129 | bool notify = false; | |
130 | int retval = 0; | |
131 | ||
132 | dev_dbg(dev, "__pm_runtime_suspend()%s!\n", | |
133 | from_wq ? " from workqueue" : ""); | |
134 | ||
135 | repeat: | |
136 | if (dev->power.runtime_error) { | |
137 | retval = -EINVAL; | |
138 | goto out; | |
139 | } | |
140 | ||
141 | /* Pending resume requests take precedence over us. */ | |
142 | if (dev->power.request_pending | |
143 | && dev->power.request == RPM_REQ_RESUME) { | |
144 | retval = -EAGAIN; | |
145 | goto out; | |
146 | } | |
147 | ||
148 | /* Other scheduled or pending requests need to be canceled. */ | |
149 | pm_runtime_cancel_pending(dev); | |
150 | ||
151 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
152 | retval = 1; | |
153 | else if (dev->power.runtime_status == RPM_RESUMING | |
154 | || dev->power.disable_depth > 0 | |
155 | || atomic_read(&dev->power.usage_count) > 0) | |
156 | retval = -EAGAIN; | |
157 | else if (!pm_children_suspended(dev)) | |
158 | retval = -EBUSY; | |
159 | if (retval) | |
160 | goto out; | |
161 | ||
162 | if (dev->power.runtime_status == RPM_SUSPENDING) { | |
163 | DEFINE_WAIT(wait); | |
164 | ||
165 | if (from_wq) { | |
166 | retval = -EINPROGRESS; | |
167 | goto out; | |
168 | } | |
169 | ||
170 | /* Wait for the other suspend running in parallel with us. */ | |
171 | for (;;) { | |
172 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
173 | TASK_UNINTERRUPTIBLE); | |
174 | if (dev->power.runtime_status != RPM_SUSPENDING) | |
175 | break; | |
176 | ||
177 | spin_unlock_irq(&dev->power.lock); | |
178 | ||
179 | schedule(); | |
180 | ||
181 | spin_lock_irq(&dev->power.lock); | |
182 | } | |
183 | finish_wait(&dev->power.wait_queue, &wait); | |
184 | goto repeat; | |
185 | } | |
186 | ||
187 | dev->power.runtime_status = RPM_SUSPENDING; | |
188 | ||
189 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) { | |
190 | spin_unlock_irq(&dev->power.lock); | |
191 | ||
192 | retval = dev->bus->pm->runtime_suspend(dev); | |
193 | ||
194 | spin_lock_irq(&dev->power.lock); | |
195 | dev->power.runtime_error = retval; | |
196 | } else { | |
197 | retval = -ENOSYS; | |
198 | } | |
199 | ||
200 | if (retval) { | |
201 | dev->power.runtime_status = RPM_ACTIVE; | |
202 | pm_runtime_cancel_pending(dev); | |
203 | dev->power.deferred_resume = false; | |
204 | ||
205 | if (retval == -EAGAIN || retval == -EBUSY) { | |
206 | notify = true; | |
207 | dev->power.runtime_error = 0; | |
208 | } | |
209 | } else { | |
210 | dev->power.runtime_status = RPM_SUSPENDED; | |
211 | ||
212 | if (dev->parent) { | |
213 | parent = dev->parent; | |
214 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
215 | } | |
216 | } | |
217 | wake_up_all(&dev->power.wait_queue); | |
218 | ||
219 | if (dev->power.deferred_resume) { | |
220 | dev->power.deferred_resume = false; | |
221 | __pm_runtime_resume(dev, false); | |
222 | retval = -EAGAIN; | |
223 | goto out; | |
224 | } | |
225 | ||
226 | if (notify) | |
227 | __pm_runtime_idle(dev); | |
228 | ||
229 | if (parent && !parent->power.ignore_children) { | |
230 | spin_unlock_irq(&dev->power.lock); | |
231 | ||
232 | pm_request_idle(parent); | |
233 | ||
234 | spin_lock_irq(&dev->power.lock); | |
235 | } | |
236 | ||
237 | out: | |
238 | dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval); | |
239 | ||
240 | return retval; | |
241 | } | |
242 | ||
243 | /** | |
244 | * pm_runtime_suspend - Carry out run-time suspend of given device. | |
245 | * @dev: Device to suspend. | |
246 | */ | |
247 | int pm_runtime_suspend(struct device *dev) | |
248 | { | |
249 | int retval; | |
250 | ||
251 | spin_lock_irq(&dev->power.lock); | |
252 | retval = __pm_runtime_suspend(dev, false); | |
253 | spin_unlock_irq(&dev->power.lock); | |
254 | ||
255 | return retval; | |
256 | } | |
257 | EXPORT_SYMBOL_GPL(pm_runtime_suspend); | |
258 | ||
259 | /** | |
260 | * __pm_runtime_resume - Carry out run-time resume of given device. | |
261 | * @dev: Device to resume. | |
262 | * @from_wq: If set, the function has been called via pm_wq. | |
263 | * | |
264 | * Check if the device can be woken up and run the ->runtime_resume() callback | |
265 | * provided by its bus type. If another resume has been started earlier, wait | |
266 | * for it to finish. If there's a suspend running in parallel with this | |
267 | * function, wait for it to finish and resume the device. Cancel any scheduled | |
268 | * or pending requests. | |
269 | * | |
270 | * This function must be called under dev->power.lock with interrupts disabled. | |
271 | */ | |
272 | int __pm_runtime_resume(struct device *dev, bool from_wq) | |
273 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
274 | { | |
275 | struct device *parent = NULL; | |
276 | int retval = 0; | |
277 | ||
278 | dev_dbg(dev, "__pm_runtime_resume()%s!\n", | |
279 | from_wq ? " from workqueue" : ""); | |
280 | ||
281 | repeat: | |
282 | if (dev->power.runtime_error) { | |
283 | retval = -EINVAL; | |
284 | goto out; | |
285 | } | |
286 | ||
287 | pm_runtime_cancel_pending(dev); | |
288 | ||
289 | if (dev->power.runtime_status == RPM_ACTIVE) | |
290 | retval = 1; | |
291 | else if (dev->power.disable_depth > 0) | |
292 | retval = -EAGAIN; | |
293 | if (retval) | |
294 | goto out; | |
295 | ||
296 | if (dev->power.runtime_status == RPM_RESUMING | |
297 | || dev->power.runtime_status == RPM_SUSPENDING) { | |
298 | DEFINE_WAIT(wait); | |
299 | ||
300 | if (from_wq) { | |
301 | if (dev->power.runtime_status == RPM_SUSPENDING) | |
302 | dev->power.deferred_resume = true; | |
303 | retval = -EINPROGRESS; | |
304 | goto out; | |
305 | } | |
306 | ||
307 | /* Wait for the operation carried out in parallel with us. */ | |
308 | for (;;) { | |
309 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
310 | TASK_UNINTERRUPTIBLE); | |
311 | if (dev->power.runtime_status != RPM_RESUMING | |
312 | && dev->power.runtime_status != RPM_SUSPENDING) | |
313 | break; | |
314 | ||
315 | spin_unlock_irq(&dev->power.lock); | |
316 | ||
317 | schedule(); | |
318 | ||
319 | spin_lock_irq(&dev->power.lock); | |
320 | } | |
321 | finish_wait(&dev->power.wait_queue, &wait); | |
322 | goto repeat; | |
323 | } | |
324 | ||
325 | if (!parent && dev->parent) { | |
326 | /* | |
327 | * Increment the parent's resume counter and resume it if | |
328 | * necessary. | |
329 | */ | |
330 | parent = dev->parent; | |
862f89b3 | 331 | spin_unlock(&dev->power.lock); |
5e928f77 RW |
332 | |
333 | pm_runtime_get_noresume(parent); | |
334 | ||
862f89b3 | 335 | spin_lock(&parent->power.lock); |
5e928f77 RW |
336 | /* |
337 | * We can resume if the parent's run-time PM is disabled or it | |
338 | * is set to ignore children. | |
339 | */ | |
340 | if (!parent->power.disable_depth | |
341 | && !parent->power.ignore_children) { | |
342 | __pm_runtime_resume(parent, false); | |
343 | if (parent->power.runtime_status != RPM_ACTIVE) | |
344 | retval = -EBUSY; | |
345 | } | |
862f89b3 | 346 | spin_unlock(&parent->power.lock); |
5e928f77 | 347 | |
862f89b3 | 348 | spin_lock(&dev->power.lock); |
5e928f77 RW |
349 | if (retval) |
350 | goto out; | |
351 | goto repeat; | |
352 | } | |
353 | ||
354 | dev->power.runtime_status = RPM_RESUMING; | |
355 | ||
356 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) { | |
357 | spin_unlock_irq(&dev->power.lock); | |
358 | ||
359 | retval = dev->bus->pm->runtime_resume(dev); | |
360 | ||
361 | spin_lock_irq(&dev->power.lock); | |
362 | dev->power.runtime_error = retval; | |
363 | } else { | |
364 | retval = -ENOSYS; | |
365 | } | |
366 | ||
367 | if (retval) { | |
368 | dev->power.runtime_status = RPM_SUSPENDED; | |
369 | pm_runtime_cancel_pending(dev); | |
370 | } else { | |
371 | dev->power.runtime_status = RPM_ACTIVE; | |
372 | if (parent) | |
373 | atomic_inc(&parent->power.child_count); | |
374 | } | |
375 | wake_up_all(&dev->power.wait_queue); | |
376 | ||
377 | if (!retval) | |
378 | __pm_request_idle(dev); | |
379 | ||
380 | out: | |
381 | if (parent) { | |
382 | spin_unlock_irq(&dev->power.lock); | |
383 | ||
384 | pm_runtime_put(parent); | |
385 | ||
386 | spin_lock_irq(&dev->power.lock); | |
387 | } | |
388 | ||
389 | dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval); | |
390 | ||
391 | return retval; | |
392 | } | |
393 | ||
394 | /** | |
395 | * pm_runtime_resume - Carry out run-time resume of given device. | |
396 | * @dev: Device to suspend. | |
397 | */ | |
398 | int pm_runtime_resume(struct device *dev) | |
399 | { | |
400 | int retval; | |
401 | ||
402 | spin_lock_irq(&dev->power.lock); | |
403 | retval = __pm_runtime_resume(dev, false); | |
404 | spin_unlock_irq(&dev->power.lock); | |
405 | ||
406 | return retval; | |
407 | } | |
408 | EXPORT_SYMBOL_GPL(pm_runtime_resume); | |
409 | ||
410 | /** | |
411 | * pm_runtime_work - Universal run-time PM work function. | |
412 | * @work: Work structure used for scheduling the execution of this function. | |
413 | * | |
414 | * Use @work to get the device object the work is to be done for, determine what | |
415 | * is to be done and execute the appropriate run-time PM function. | |
416 | */ | |
417 | static void pm_runtime_work(struct work_struct *work) | |
418 | { | |
419 | struct device *dev = container_of(work, struct device, power.work); | |
420 | enum rpm_request req; | |
421 | ||
422 | spin_lock_irq(&dev->power.lock); | |
423 | ||
424 | if (!dev->power.request_pending) | |
425 | goto out; | |
426 | ||
427 | req = dev->power.request; | |
428 | dev->power.request = RPM_REQ_NONE; | |
429 | dev->power.request_pending = false; | |
430 | ||
431 | switch (req) { | |
432 | case RPM_REQ_NONE: | |
433 | break; | |
434 | case RPM_REQ_IDLE: | |
435 | __pm_runtime_idle(dev); | |
436 | break; | |
437 | case RPM_REQ_SUSPEND: | |
438 | __pm_runtime_suspend(dev, true); | |
439 | break; | |
440 | case RPM_REQ_RESUME: | |
441 | __pm_runtime_resume(dev, true); | |
442 | break; | |
443 | } | |
444 | ||
445 | out: | |
446 | spin_unlock_irq(&dev->power.lock); | |
447 | } | |
448 | ||
449 | /** | |
450 | * __pm_request_idle - Submit an idle notification request for given device. | |
451 | * @dev: Device to handle. | |
452 | * | |
453 | * Check if the device's run-time PM status is correct for suspending the device | |
454 | * and queue up a request to run __pm_runtime_idle() for it. | |
455 | * | |
456 | * This function must be called under dev->power.lock with interrupts disabled. | |
457 | */ | |
458 | static int __pm_request_idle(struct device *dev) | |
459 | { | |
460 | int retval = 0; | |
461 | ||
462 | if (dev->power.runtime_error) | |
463 | retval = -EINVAL; | |
464 | else if (atomic_read(&dev->power.usage_count) > 0 | |
465 | || dev->power.disable_depth > 0 | |
466 | || dev->power.runtime_status == RPM_SUSPENDED | |
467 | || dev->power.runtime_status == RPM_SUSPENDING) | |
468 | retval = -EAGAIN; | |
469 | else if (!pm_children_suspended(dev)) | |
470 | retval = -EBUSY; | |
471 | if (retval) | |
472 | return retval; | |
473 | ||
474 | if (dev->power.request_pending) { | |
475 | /* Any requests other then RPM_REQ_IDLE take precedence. */ | |
476 | if (dev->power.request == RPM_REQ_NONE) | |
477 | dev->power.request = RPM_REQ_IDLE; | |
478 | else if (dev->power.request != RPM_REQ_IDLE) | |
479 | retval = -EAGAIN; | |
480 | return retval; | |
481 | } | |
482 | ||
483 | dev->power.request = RPM_REQ_IDLE; | |
484 | dev->power.request_pending = true; | |
485 | queue_work(pm_wq, &dev->power.work); | |
486 | ||
487 | return retval; | |
488 | } | |
489 | ||
490 | /** | |
491 | * pm_request_idle - Submit an idle notification request for given device. | |
492 | * @dev: Device to handle. | |
493 | */ | |
494 | int pm_request_idle(struct device *dev) | |
495 | { | |
496 | unsigned long flags; | |
497 | int retval; | |
498 | ||
499 | spin_lock_irqsave(&dev->power.lock, flags); | |
500 | retval = __pm_request_idle(dev); | |
501 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
502 | ||
503 | return retval; | |
504 | } | |
505 | EXPORT_SYMBOL_GPL(pm_request_idle); | |
506 | ||
507 | /** | |
508 | * __pm_request_suspend - Submit a suspend request for given device. | |
509 | * @dev: Device to suspend. | |
510 | * | |
511 | * This function must be called under dev->power.lock with interrupts disabled. | |
512 | */ | |
513 | static int __pm_request_suspend(struct device *dev) | |
514 | { | |
515 | int retval = 0; | |
516 | ||
517 | if (dev->power.runtime_error) | |
518 | return -EINVAL; | |
519 | ||
520 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
521 | retval = 1; | |
522 | else if (atomic_read(&dev->power.usage_count) > 0 | |
523 | || dev->power.disable_depth > 0) | |
524 | retval = -EAGAIN; | |
525 | else if (dev->power.runtime_status == RPM_SUSPENDING) | |
526 | retval = -EINPROGRESS; | |
527 | else if (!pm_children_suspended(dev)) | |
528 | retval = -EBUSY; | |
529 | if (retval < 0) | |
530 | return retval; | |
531 | ||
532 | pm_runtime_deactivate_timer(dev); | |
533 | ||
534 | if (dev->power.request_pending) { | |
535 | /* | |
536 | * Pending resume requests take precedence over us, but we can | |
537 | * overtake any other pending request. | |
538 | */ | |
539 | if (dev->power.request == RPM_REQ_RESUME) | |
540 | retval = -EAGAIN; | |
541 | else if (dev->power.request != RPM_REQ_SUSPEND) | |
542 | dev->power.request = retval ? | |
543 | RPM_REQ_NONE : RPM_REQ_SUSPEND; | |
544 | return retval; | |
545 | } else if (retval) { | |
546 | return retval; | |
547 | } | |
548 | ||
549 | dev->power.request = RPM_REQ_SUSPEND; | |
550 | dev->power.request_pending = true; | |
551 | queue_work(pm_wq, &dev->power.work); | |
552 | ||
553 | return 0; | |
554 | } | |
555 | ||
556 | /** | |
557 | * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). | |
558 | * @data: Device pointer passed by pm_schedule_suspend(). | |
559 | * | |
560 | * Check if the time is right and execute __pm_request_suspend() in that case. | |
561 | */ | |
562 | static void pm_suspend_timer_fn(unsigned long data) | |
563 | { | |
564 | struct device *dev = (struct device *)data; | |
565 | unsigned long flags; | |
566 | unsigned long expires; | |
567 | ||
568 | spin_lock_irqsave(&dev->power.lock, flags); | |
569 | ||
570 | expires = dev->power.timer_expires; | |
571 | /* If 'expire' is after 'jiffies' we've been called too early. */ | |
572 | if (expires > 0 && !time_after(expires, jiffies)) { | |
573 | dev->power.timer_expires = 0; | |
574 | __pm_request_suspend(dev); | |
575 | } | |
576 | ||
577 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
578 | } | |
579 | ||
580 | /** | |
581 | * pm_schedule_suspend - Set up a timer to submit a suspend request in future. | |
582 | * @dev: Device to suspend. | |
583 | * @delay: Time to wait before submitting a suspend request, in milliseconds. | |
584 | */ | |
585 | int pm_schedule_suspend(struct device *dev, unsigned int delay) | |
586 | { | |
587 | unsigned long flags; | |
588 | int retval = 0; | |
589 | ||
590 | spin_lock_irqsave(&dev->power.lock, flags); | |
591 | ||
592 | if (dev->power.runtime_error) { | |
593 | retval = -EINVAL; | |
594 | goto out; | |
595 | } | |
596 | ||
597 | if (!delay) { | |
598 | retval = __pm_request_suspend(dev); | |
599 | goto out; | |
600 | } | |
601 | ||
602 | pm_runtime_deactivate_timer(dev); | |
603 | ||
604 | if (dev->power.request_pending) { | |
605 | /* | |
606 | * Pending resume requests take precedence over us, but any | |
607 | * other pending requests have to be canceled. | |
608 | */ | |
609 | if (dev->power.request == RPM_REQ_RESUME) { | |
610 | retval = -EAGAIN; | |
611 | goto out; | |
612 | } | |
613 | dev->power.request = RPM_REQ_NONE; | |
614 | } | |
615 | ||
616 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
617 | retval = 1; | |
618 | else if (dev->power.runtime_status == RPM_SUSPENDING) | |
619 | retval = -EINPROGRESS; | |
620 | else if (atomic_read(&dev->power.usage_count) > 0 | |
621 | || dev->power.disable_depth > 0) | |
622 | retval = -EAGAIN; | |
623 | else if (!pm_children_suspended(dev)) | |
624 | retval = -EBUSY; | |
625 | if (retval) | |
626 | goto out; | |
627 | ||
628 | dev->power.timer_expires = jiffies + msecs_to_jiffies(delay); | |
629 | mod_timer(&dev->power.suspend_timer, dev->power.timer_expires); | |
630 | ||
631 | out: | |
632 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
633 | ||
634 | return retval; | |
635 | } | |
636 | EXPORT_SYMBOL_GPL(pm_schedule_suspend); | |
637 | ||
638 | /** | |
639 | * pm_request_resume - Submit a resume request for given device. | |
640 | * @dev: Device to resume. | |
641 | * | |
642 | * This function must be called under dev->power.lock with interrupts disabled. | |
643 | */ | |
644 | static int __pm_request_resume(struct device *dev) | |
645 | { | |
646 | int retval = 0; | |
647 | ||
648 | if (dev->power.runtime_error) | |
649 | return -EINVAL; | |
650 | ||
651 | if (dev->power.runtime_status == RPM_ACTIVE) | |
652 | retval = 1; | |
653 | else if (dev->power.runtime_status == RPM_RESUMING) | |
654 | retval = -EINPROGRESS; | |
655 | else if (dev->power.disable_depth > 0) | |
656 | retval = -EAGAIN; | |
657 | if (retval < 0) | |
658 | return retval; | |
659 | ||
660 | pm_runtime_deactivate_timer(dev); | |
661 | ||
662 | if (dev->power.request_pending) { | |
663 | /* If non-resume request is pending, we can overtake it. */ | |
664 | dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME; | |
665 | return retval; | |
666 | } else if (retval) { | |
667 | return retval; | |
668 | } | |
669 | ||
670 | dev->power.request = RPM_REQ_RESUME; | |
671 | dev->power.request_pending = true; | |
672 | queue_work(pm_wq, &dev->power.work); | |
673 | ||
674 | return retval; | |
675 | } | |
676 | ||
677 | /** | |
678 | * pm_request_resume - Submit a resume request for given device. | |
679 | * @dev: Device to resume. | |
680 | */ | |
681 | int pm_request_resume(struct device *dev) | |
682 | { | |
683 | unsigned long flags; | |
684 | int retval; | |
685 | ||
686 | spin_lock_irqsave(&dev->power.lock, flags); | |
687 | retval = __pm_request_resume(dev); | |
688 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
689 | ||
690 | return retval; | |
691 | } | |
692 | EXPORT_SYMBOL_GPL(pm_request_resume); | |
693 | ||
694 | /** | |
695 | * __pm_runtime_get - Reference count a device and wake it up, if necessary. | |
696 | * @dev: Device to handle. | |
697 | * @sync: If set and the device is suspended, resume it synchronously. | |
698 | * | |
699 | * Increment the usage count of the device and if it was zero previously, | |
700 | * resume it or submit a resume request for it, depending on the value of @sync. | |
701 | */ | |
702 | int __pm_runtime_get(struct device *dev, bool sync) | |
703 | { | |
704 | int retval = 1; | |
705 | ||
706 | if (atomic_add_return(1, &dev->power.usage_count) == 1) | |
707 | retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); | |
708 | ||
709 | return retval; | |
710 | } | |
711 | EXPORT_SYMBOL_GPL(__pm_runtime_get); | |
712 | ||
713 | /** | |
714 | * __pm_runtime_put - Decrement the device's usage counter and notify its bus. | |
715 | * @dev: Device to handle. | |
716 | * @sync: If the device's bus type is to be notified, do that synchronously. | |
717 | * | |
718 | * Decrement the usage count of the device and if it reaches zero, carry out a | |
719 | * synchronous idle notification or submit an idle notification request for it, | |
720 | * depending on the value of @sync. | |
721 | */ | |
722 | int __pm_runtime_put(struct device *dev, bool sync) | |
723 | { | |
724 | int retval = 0; | |
725 | ||
726 | if (atomic_dec_and_test(&dev->power.usage_count)) | |
727 | retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev); | |
728 | ||
729 | return retval; | |
730 | } | |
731 | EXPORT_SYMBOL_GPL(__pm_runtime_put); | |
732 | ||
733 | /** | |
734 | * __pm_runtime_set_status - Set run-time PM status of a device. | |
735 | * @dev: Device to handle. | |
736 | * @status: New run-time PM status of the device. | |
737 | * | |
738 | * If run-time PM of the device is disabled or its power.runtime_error field is | |
739 | * different from zero, the status may be changed either to RPM_ACTIVE, or to | |
740 | * RPM_SUSPENDED, as long as that reflects the actual state of the device. | |
741 | * However, if the device has a parent and the parent is not active, and the | |
742 | * parent's power.ignore_children flag is unset, the device's status cannot be | |
743 | * set to RPM_ACTIVE, so -EBUSY is returned in that case. | |
744 | * | |
745 | * If successful, __pm_runtime_set_status() clears the power.runtime_error field | |
746 | * and the device parent's counter of unsuspended children is modified to | |
747 | * reflect the new status. If the new status is RPM_SUSPENDED, an idle | |
748 | * notification request for the parent is submitted. | |
749 | */ | |
750 | int __pm_runtime_set_status(struct device *dev, unsigned int status) | |
751 | { | |
752 | struct device *parent = dev->parent; | |
753 | unsigned long flags; | |
754 | bool notify_parent = false; | |
755 | int error = 0; | |
756 | ||
757 | if (status != RPM_ACTIVE && status != RPM_SUSPENDED) | |
758 | return -EINVAL; | |
759 | ||
760 | spin_lock_irqsave(&dev->power.lock, flags); | |
761 | ||
762 | if (!dev->power.runtime_error && !dev->power.disable_depth) { | |
763 | error = -EAGAIN; | |
764 | goto out; | |
765 | } | |
766 | ||
767 | if (dev->power.runtime_status == status) | |
768 | goto out_set; | |
769 | ||
770 | if (status == RPM_SUSPENDED) { | |
771 | /* It always is possible to set the status to 'suspended'. */ | |
772 | if (parent) { | |
773 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
774 | notify_parent = !parent->power.ignore_children; | |
775 | } | |
776 | goto out_set; | |
777 | } | |
778 | ||
779 | if (parent) { | |
862f89b3 | 780 | spin_lock(&parent->power.lock); |
5e928f77 RW |
781 | |
782 | /* | |
783 | * It is invalid to put an active child under a parent that is | |
784 | * not active, has run-time PM enabled and the | |
785 | * 'power.ignore_children' flag unset. | |
786 | */ | |
787 | if (!parent->power.disable_depth | |
788 | && !parent->power.ignore_children | |
789 | && parent->power.runtime_status != RPM_ACTIVE) { | |
790 | error = -EBUSY; | |
791 | } else { | |
792 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
793 | atomic_inc(&parent->power.child_count); | |
794 | } | |
795 | ||
862f89b3 | 796 | spin_unlock(&parent->power.lock); |
5e928f77 RW |
797 | |
798 | if (error) | |
799 | goto out; | |
800 | } | |
801 | ||
802 | out_set: | |
803 | dev->power.runtime_status = status; | |
804 | dev->power.runtime_error = 0; | |
805 | out: | |
806 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
807 | ||
808 | if (notify_parent) | |
809 | pm_request_idle(parent); | |
810 | ||
811 | return error; | |
812 | } | |
813 | EXPORT_SYMBOL_GPL(__pm_runtime_set_status); | |
814 | ||
815 | /** | |
816 | * __pm_runtime_barrier - Cancel pending requests and wait for completions. | |
817 | * @dev: Device to handle. | |
818 | * | |
819 | * Flush all pending requests for the device from pm_wq and wait for all | |
820 | * run-time PM operations involving the device in progress to complete. | |
821 | * | |
822 | * Should be called under dev->power.lock with interrupts disabled. | |
823 | */ | |
824 | static void __pm_runtime_barrier(struct device *dev) | |
825 | { | |
826 | pm_runtime_deactivate_timer(dev); | |
827 | ||
828 | if (dev->power.request_pending) { | |
829 | dev->power.request = RPM_REQ_NONE; | |
830 | spin_unlock_irq(&dev->power.lock); | |
831 | ||
832 | cancel_work_sync(&dev->power.work); | |
833 | ||
834 | spin_lock_irq(&dev->power.lock); | |
835 | dev->power.request_pending = false; | |
836 | } | |
837 | ||
838 | if (dev->power.runtime_status == RPM_SUSPENDING | |
839 | || dev->power.runtime_status == RPM_RESUMING | |
840 | || dev->power.idle_notification) { | |
841 | DEFINE_WAIT(wait); | |
842 | ||
843 | /* Suspend, wake-up or idle notification in progress. */ | |
844 | for (;;) { | |
845 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
846 | TASK_UNINTERRUPTIBLE); | |
847 | if (dev->power.runtime_status != RPM_SUSPENDING | |
848 | && dev->power.runtime_status != RPM_RESUMING | |
849 | && !dev->power.idle_notification) | |
850 | break; | |
851 | spin_unlock_irq(&dev->power.lock); | |
852 | ||
853 | schedule(); | |
854 | ||
855 | spin_lock_irq(&dev->power.lock); | |
856 | } | |
857 | finish_wait(&dev->power.wait_queue, &wait); | |
858 | } | |
859 | } | |
860 | ||
861 | /** | |
862 | * pm_runtime_barrier - Flush pending requests and wait for completions. | |
863 | * @dev: Device to handle. | |
864 | * | |
865 | * Prevent the device from being suspended by incrementing its usage counter and | |
866 | * if there's a pending resume request for the device, wake the device up. | |
867 | * Next, make sure that all pending requests for the device have been flushed | |
868 | * from pm_wq and wait for all run-time PM operations involving the device in | |
869 | * progress to complete. | |
870 | * | |
871 | * Return value: | |
872 | * 1, if there was a resume request pending and the device had to be woken up, | |
873 | * 0, otherwise | |
874 | */ | |
875 | int pm_runtime_barrier(struct device *dev) | |
876 | { | |
877 | int retval = 0; | |
878 | ||
879 | pm_runtime_get_noresume(dev); | |
880 | spin_lock_irq(&dev->power.lock); | |
881 | ||
882 | if (dev->power.request_pending | |
883 | && dev->power.request == RPM_REQ_RESUME) { | |
884 | __pm_runtime_resume(dev, false); | |
885 | retval = 1; | |
886 | } | |
887 | ||
888 | __pm_runtime_barrier(dev); | |
889 | ||
890 | spin_unlock_irq(&dev->power.lock); | |
891 | pm_runtime_put_noidle(dev); | |
892 | ||
893 | return retval; | |
894 | } | |
895 | EXPORT_SYMBOL_GPL(pm_runtime_barrier); | |
896 | ||
897 | /** | |
898 | * __pm_runtime_disable - Disable run-time PM of a device. | |
899 | * @dev: Device to handle. | |
900 | * @check_resume: If set, check if there's a resume request for the device. | |
901 | * | |
902 | * Increment power.disable_depth for the device and if was zero previously, | |
903 | * cancel all pending run-time PM requests for the device and wait for all | |
904 | * operations in progress to complete. The device can be either active or | |
905 | * suspended after its run-time PM has been disabled. | |
906 | * | |
907 | * If @check_resume is set and there's a resume request pending when | |
908 | * __pm_runtime_disable() is called and power.disable_depth is zero, the | |
909 | * function will wake up the device before disabling its run-time PM. | |
910 | */ | |
911 | void __pm_runtime_disable(struct device *dev, bool check_resume) | |
912 | { | |
913 | spin_lock_irq(&dev->power.lock); | |
914 | ||
915 | if (dev->power.disable_depth > 0) { | |
916 | dev->power.disable_depth++; | |
917 | goto out; | |
918 | } | |
919 | ||
920 | /* | |
921 | * Wake up the device if there's a resume request pending, because that | |
922 | * means there probably is some I/O to process and disabling run-time PM | |
923 | * shouldn't prevent the device from processing the I/O. | |
924 | */ | |
925 | if (check_resume && dev->power.request_pending | |
926 | && dev->power.request == RPM_REQ_RESUME) { | |
927 | /* | |
928 | * Prevent suspends and idle notifications from being carried | |
929 | * out after we have woken up the device. | |
930 | */ | |
931 | pm_runtime_get_noresume(dev); | |
932 | ||
933 | __pm_runtime_resume(dev, false); | |
934 | ||
935 | pm_runtime_put_noidle(dev); | |
936 | } | |
937 | ||
938 | if (!dev->power.disable_depth++) | |
939 | __pm_runtime_barrier(dev); | |
940 | ||
941 | out: | |
942 | spin_unlock_irq(&dev->power.lock); | |
943 | } | |
944 | EXPORT_SYMBOL_GPL(__pm_runtime_disable); | |
945 | ||
946 | /** | |
947 | * pm_runtime_enable - Enable run-time PM of a device. | |
948 | * @dev: Device to handle. | |
949 | */ | |
950 | void pm_runtime_enable(struct device *dev) | |
951 | { | |
952 | unsigned long flags; | |
953 | ||
954 | spin_lock_irqsave(&dev->power.lock, flags); | |
955 | ||
956 | if (dev->power.disable_depth > 0) | |
957 | dev->power.disable_depth--; | |
958 | else | |
959 | dev_warn(dev, "Unbalanced %s!\n", __func__); | |
960 | ||
961 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
962 | } | |
963 | EXPORT_SYMBOL_GPL(pm_runtime_enable); | |
964 | ||
965 | /** | |
966 | * pm_runtime_init - Initialize run-time PM fields in given device object. | |
967 | * @dev: Device object to initialize. | |
968 | */ | |
969 | void pm_runtime_init(struct device *dev) | |
970 | { | |
971 | spin_lock_init(&dev->power.lock); | |
972 | ||
973 | dev->power.runtime_status = RPM_SUSPENDED; | |
974 | dev->power.idle_notification = false; | |
975 | ||
976 | dev->power.disable_depth = 1; | |
977 | atomic_set(&dev->power.usage_count, 0); | |
978 | ||
979 | dev->power.runtime_error = 0; | |
980 | ||
981 | atomic_set(&dev->power.child_count, 0); | |
982 | pm_suspend_ignore_children(dev, false); | |
983 | ||
984 | dev->power.request_pending = false; | |
985 | dev->power.request = RPM_REQ_NONE; | |
986 | dev->power.deferred_resume = false; | |
987 | INIT_WORK(&dev->power.work, pm_runtime_work); | |
988 | ||
989 | dev->power.timer_expires = 0; | |
990 | setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn, | |
991 | (unsigned long)dev); | |
992 | ||
993 | init_waitqueue_head(&dev->power.wait_queue); | |
994 | } | |
995 | ||
996 | /** | |
997 | * pm_runtime_remove - Prepare for removing a device from device hierarchy. | |
998 | * @dev: Device object being removed from device hierarchy. | |
999 | */ | |
1000 | void pm_runtime_remove(struct device *dev) | |
1001 | { | |
1002 | __pm_runtime_disable(dev, false); | |
1003 | ||
1004 | /* Change the status back to 'suspended' to match the initial status. */ | |
1005 | if (dev->power.runtime_status == RPM_ACTIVE) | |
1006 | pm_runtime_set_suspended(dev); | |
1007 | } |