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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 | ||
54 | dev_dbg(dev, "__pm_runtime_idle()!\n"); | |
55 | ||
56 | if (dev->power.runtime_error) | |
57 | retval = -EINVAL; | |
58 | else if (dev->power.idle_notification) | |
59 | retval = -EINPROGRESS; | |
60 | else if (atomic_read(&dev->power.usage_count) > 0 | |
61 | || dev->power.disable_depth > 0 | |
62 | || dev->power.runtime_status != RPM_ACTIVE) | |
63 | retval = -EAGAIN; | |
64 | else if (!pm_children_suspended(dev)) | |
65 | retval = -EBUSY; | |
66 | if (retval) | |
67 | goto out; | |
68 | ||
69 | if (dev->power.request_pending) { | |
70 | /* | |
71 | * If an idle notification request is pending, cancel it. Any | |
72 | * other pending request takes precedence over us. | |
73 | */ | |
74 | if (dev->power.request == RPM_REQ_IDLE) { | |
75 | dev->power.request = RPM_REQ_NONE; | |
76 | } else if (dev->power.request != RPM_REQ_NONE) { | |
77 | retval = -EAGAIN; | |
78 | goto out; | |
79 | } | |
80 | } | |
81 | ||
82 | dev->power.idle_notification = true; | |
83 | ||
84 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) { | |
85 | spin_unlock_irq(&dev->power.lock); | |
86 | ||
87 | dev->bus->pm->runtime_idle(dev); | |
88 | ||
89 | spin_lock_irq(&dev->power.lock); | |
90 | } | |
91 | ||
92 | dev->power.idle_notification = false; | |
93 | wake_up_all(&dev->power.wait_queue); | |
94 | ||
95 | out: | |
96 | dev_dbg(dev, "__pm_runtime_idle() returns %d!\n", retval); | |
97 | ||
98 | return retval; | |
99 | } | |
100 | ||
101 | /** | |
102 | * pm_runtime_idle - Notify device bus type if the device can be suspended. | |
103 | * @dev: Device to notify the bus type about. | |
104 | */ | |
105 | int pm_runtime_idle(struct device *dev) | |
106 | { | |
107 | int retval; | |
108 | ||
109 | spin_lock_irq(&dev->power.lock); | |
110 | retval = __pm_runtime_idle(dev); | |
111 | spin_unlock_irq(&dev->power.lock); | |
112 | ||
113 | return retval; | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(pm_runtime_idle); | |
116 | ||
117 | /** | |
118 | * __pm_runtime_suspend - Carry out run-time suspend of given device. | |
119 | * @dev: Device to suspend. | |
120 | * @from_wq: If set, the function has been called via pm_wq. | |
121 | * | |
122 | * Check if the device can be suspended and run the ->runtime_suspend() callback | |
123 | * provided by its bus type. If another suspend has been started earlier, wait | |
124 | * for it to finish. If an idle notification or suspend request is pending or | |
125 | * scheduled, cancel it. | |
126 | * | |
127 | * This function must be called under dev->power.lock with interrupts disabled. | |
128 | */ | |
129 | int __pm_runtime_suspend(struct device *dev, bool from_wq) | |
130 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
131 | { | |
132 | struct device *parent = NULL; | |
133 | bool notify = false; | |
134 | int retval = 0; | |
135 | ||
136 | dev_dbg(dev, "__pm_runtime_suspend()%s!\n", | |
137 | from_wq ? " from workqueue" : ""); | |
138 | ||
139 | repeat: | |
140 | if (dev->power.runtime_error) { | |
141 | retval = -EINVAL; | |
142 | goto out; | |
143 | } | |
144 | ||
145 | /* Pending resume requests take precedence over us. */ | |
146 | if (dev->power.request_pending | |
147 | && dev->power.request == RPM_REQ_RESUME) { | |
148 | retval = -EAGAIN; | |
149 | goto out; | |
150 | } | |
151 | ||
152 | /* Other scheduled or pending requests need to be canceled. */ | |
153 | pm_runtime_cancel_pending(dev); | |
154 | ||
155 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
156 | retval = 1; | |
157 | else if (dev->power.runtime_status == RPM_RESUMING | |
158 | || dev->power.disable_depth > 0 | |
159 | || atomic_read(&dev->power.usage_count) > 0) | |
160 | retval = -EAGAIN; | |
161 | else if (!pm_children_suspended(dev)) | |
162 | retval = -EBUSY; | |
163 | if (retval) | |
164 | goto out; | |
165 | ||
166 | if (dev->power.runtime_status == RPM_SUSPENDING) { | |
167 | DEFINE_WAIT(wait); | |
168 | ||
169 | if (from_wq) { | |
170 | retval = -EINPROGRESS; | |
171 | goto out; | |
172 | } | |
173 | ||
174 | /* Wait for the other suspend running in parallel with us. */ | |
175 | for (;;) { | |
176 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
177 | TASK_UNINTERRUPTIBLE); | |
178 | if (dev->power.runtime_status != RPM_SUSPENDING) | |
179 | break; | |
180 | ||
181 | spin_unlock_irq(&dev->power.lock); | |
182 | ||
183 | schedule(); | |
184 | ||
185 | spin_lock_irq(&dev->power.lock); | |
186 | } | |
187 | finish_wait(&dev->power.wait_queue, &wait); | |
188 | goto repeat; | |
189 | } | |
190 | ||
191 | dev->power.runtime_status = RPM_SUSPENDING; | |
192 | ||
193 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) { | |
194 | spin_unlock_irq(&dev->power.lock); | |
195 | ||
196 | retval = dev->bus->pm->runtime_suspend(dev); | |
197 | ||
198 | spin_lock_irq(&dev->power.lock); | |
199 | dev->power.runtime_error = retval; | |
200 | } else { | |
201 | retval = -ENOSYS; | |
202 | } | |
203 | ||
204 | if (retval) { | |
205 | dev->power.runtime_status = RPM_ACTIVE; | |
206 | pm_runtime_cancel_pending(dev); | |
207 | dev->power.deferred_resume = false; | |
208 | ||
209 | if (retval == -EAGAIN || retval == -EBUSY) { | |
210 | notify = true; | |
211 | dev->power.runtime_error = 0; | |
212 | } | |
213 | } else { | |
214 | dev->power.runtime_status = RPM_SUSPENDED; | |
215 | ||
216 | if (dev->parent) { | |
217 | parent = dev->parent; | |
218 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
219 | } | |
220 | } | |
221 | wake_up_all(&dev->power.wait_queue); | |
222 | ||
223 | if (dev->power.deferred_resume) { | |
224 | dev->power.deferred_resume = false; | |
225 | __pm_runtime_resume(dev, false); | |
226 | retval = -EAGAIN; | |
227 | goto out; | |
228 | } | |
229 | ||
230 | if (notify) | |
231 | __pm_runtime_idle(dev); | |
232 | ||
233 | if (parent && !parent->power.ignore_children) { | |
234 | spin_unlock_irq(&dev->power.lock); | |
235 | ||
236 | pm_request_idle(parent); | |
237 | ||
238 | spin_lock_irq(&dev->power.lock); | |
239 | } | |
240 | ||
241 | out: | |
242 | dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval); | |
243 | ||
244 | return retval; | |
245 | } | |
246 | ||
247 | /** | |
248 | * pm_runtime_suspend - Carry out run-time suspend of given device. | |
249 | * @dev: Device to suspend. | |
250 | */ | |
251 | int pm_runtime_suspend(struct device *dev) | |
252 | { | |
253 | int retval; | |
254 | ||
255 | spin_lock_irq(&dev->power.lock); | |
256 | retval = __pm_runtime_suspend(dev, false); | |
257 | spin_unlock_irq(&dev->power.lock); | |
258 | ||
259 | return retval; | |
260 | } | |
261 | EXPORT_SYMBOL_GPL(pm_runtime_suspend); | |
262 | ||
263 | /** | |
264 | * __pm_runtime_resume - Carry out run-time resume of given device. | |
265 | * @dev: Device to resume. | |
266 | * @from_wq: If set, the function has been called via pm_wq. | |
267 | * | |
268 | * Check if the device can be woken up and run the ->runtime_resume() callback | |
269 | * provided by its bus type. If another resume has been started earlier, wait | |
270 | * for it to finish. If there's a suspend running in parallel with this | |
271 | * function, wait for it to finish and resume the device. Cancel any scheduled | |
272 | * or pending requests. | |
273 | * | |
274 | * This function must be called under dev->power.lock with interrupts disabled. | |
275 | */ | |
276 | int __pm_runtime_resume(struct device *dev, bool from_wq) | |
277 | __releases(&dev->power.lock) __acquires(&dev->power.lock) | |
278 | { | |
279 | struct device *parent = NULL; | |
280 | int retval = 0; | |
281 | ||
282 | dev_dbg(dev, "__pm_runtime_resume()%s!\n", | |
283 | from_wq ? " from workqueue" : ""); | |
284 | ||
285 | repeat: | |
286 | if (dev->power.runtime_error) { | |
287 | retval = -EINVAL; | |
288 | goto out; | |
289 | } | |
290 | ||
291 | pm_runtime_cancel_pending(dev); | |
292 | ||
293 | if (dev->power.runtime_status == RPM_ACTIVE) | |
294 | retval = 1; | |
295 | else if (dev->power.disable_depth > 0) | |
296 | retval = -EAGAIN; | |
297 | if (retval) | |
298 | goto out; | |
299 | ||
300 | if (dev->power.runtime_status == RPM_RESUMING | |
301 | || dev->power.runtime_status == RPM_SUSPENDING) { | |
302 | DEFINE_WAIT(wait); | |
303 | ||
304 | if (from_wq) { | |
305 | if (dev->power.runtime_status == RPM_SUSPENDING) | |
306 | dev->power.deferred_resume = true; | |
307 | retval = -EINPROGRESS; | |
308 | goto out; | |
309 | } | |
310 | ||
311 | /* Wait for the operation carried out in parallel with us. */ | |
312 | for (;;) { | |
313 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
314 | TASK_UNINTERRUPTIBLE); | |
315 | if (dev->power.runtime_status != RPM_RESUMING | |
316 | && dev->power.runtime_status != RPM_SUSPENDING) | |
317 | break; | |
318 | ||
319 | spin_unlock_irq(&dev->power.lock); | |
320 | ||
321 | schedule(); | |
322 | ||
323 | spin_lock_irq(&dev->power.lock); | |
324 | } | |
325 | finish_wait(&dev->power.wait_queue, &wait); | |
326 | goto repeat; | |
327 | } | |
328 | ||
329 | if (!parent && dev->parent) { | |
330 | /* | |
331 | * Increment the parent's resume counter and resume it if | |
332 | * necessary. | |
333 | */ | |
334 | parent = dev->parent; | |
335 | spin_unlock_irq(&dev->power.lock); | |
336 | ||
337 | pm_runtime_get_noresume(parent); | |
338 | ||
339 | spin_lock_irq(&parent->power.lock); | |
340 | /* | |
341 | * We can resume if the parent's run-time PM is disabled or it | |
342 | * is set to ignore children. | |
343 | */ | |
344 | if (!parent->power.disable_depth | |
345 | && !parent->power.ignore_children) { | |
346 | __pm_runtime_resume(parent, false); | |
347 | if (parent->power.runtime_status != RPM_ACTIVE) | |
348 | retval = -EBUSY; | |
349 | } | |
350 | spin_unlock_irq(&parent->power.lock); | |
351 | ||
352 | spin_lock_irq(&dev->power.lock); | |
353 | if (retval) | |
354 | goto out; | |
355 | goto repeat; | |
356 | } | |
357 | ||
358 | dev->power.runtime_status = RPM_RESUMING; | |
359 | ||
360 | if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) { | |
361 | spin_unlock_irq(&dev->power.lock); | |
362 | ||
363 | retval = dev->bus->pm->runtime_resume(dev); | |
364 | ||
365 | spin_lock_irq(&dev->power.lock); | |
366 | dev->power.runtime_error = retval; | |
367 | } else { | |
368 | retval = -ENOSYS; | |
369 | } | |
370 | ||
371 | if (retval) { | |
372 | dev->power.runtime_status = RPM_SUSPENDED; | |
373 | pm_runtime_cancel_pending(dev); | |
374 | } else { | |
375 | dev->power.runtime_status = RPM_ACTIVE; | |
376 | if (parent) | |
377 | atomic_inc(&parent->power.child_count); | |
378 | } | |
379 | wake_up_all(&dev->power.wait_queue); | |
380 | ||
381 | if (!retval) | |
382 | __pm_request_idle(dev); | |
383 | ||
384 | out: | |
385 | if (parent) { | |
386 | spin_unlock_irq(&dev->power.lock); | |
387 | ||
388 | pm_runtime_put(parent); | |
389 | ||
390 | spin_lock_irq(&dev->power.lock); | |
391 | } | |
392 | ||
393 | dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval); | |
394 | ||
395 | return retval; | |
396 | } | |
397 | ||
398 | /** | |
399 | * pm_runtime_resume - Carry out run-time resume of given device. | |
400 | * @dev: Device to suspend. | |
401 | */ | |
402 | int pm_runtime_resume(struct device *dev) | |
403 | { | |
404 | int retval; | |
405 | ||
406 | spin_lock_irq(&dev->power.lock); | |
407 | retval = __pm_runtime_resume(dev, false); | |
408 | spin_unlock_irq(&dev->power.lock); | |
409 | ||
410 | return retval; | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(pm_runtime_resume); | |
413 | ||
414 | /** | |
415 | * pm_runtime_work - Universal run-time PM work function. | |
416 | * @work: Work structure used for scheduling the execution of this function. | |
417 | * | |
418 | * Use @work to get the device object the work is to be done for, determine what | |
419 | * is to be done and execute the appropriate run-time PM function. | |
420 | */ | |
421 | static void pm_runtime_work(struct work_struct *work) | |
422 | { | |
423 | struct device *dev = container_of(work, struct device, power.work); | |
424 | enum rpm_request req; | |
425 | ||
426 | spin_lock_irq(&dev->power.lock); | |
427 | ||
428 | if (!dev->power.request_pending) | |
429 | goto out; | |
430 | ||
431 | req = dev->power.request; | |
432 | dev->power.request = RPM_REQ_NONE; | |
433 | dev->power.request_pending = false; | |
434 | ||
435 | switch (req) { | |
436 | case RPM_REQ_NONE: | |
437 | break; | |
438 | case RPM_REQ_IDLE: | |
439 | __pm_runtime_idle(dev); | |
440 | break; | |
441 | case RPM_REQ_SUSPEND: | |
442 | __pm_runtime_suspend(dev, true); | |
443 | break; | |
444 | case RPM_REQ_RESUME: | |
445 | __pm_runtime_resume(dev, true); | |
446 | break; | |
447 | } | |
448 | ||
449 | out: | |
450 | spin_unlock_irq(&dev->power.lock); | |
451 | } | |
452 | ||
453 | /** | |
454 | * __pm_request_idle - Submit an idle notification request for given device. | |
455 | * @dev: Device to handle. | |
456 | * | |
457 | * Check if the device's run-time PM status is correct for suspending the device | |
458 | * and queue up a request to run __pm_runtime_idle() for it. | |
459 | * | |
460 | * This function must be called under dev->power.lock with interrupts disabled. | |
461 | */ | |
462 | static int __pm_request_idle(struct device *dev) | |
463 | { | |
464 | int retval = 0; | |
465 | ||
466 | if (dev->power.runtime_error) | |
467 | retval = -EINVAL; | |
468 | else if (atomic_read(&dev->power.usage_count) > 0 | |
469 | || dev->power.disable_depth > 0 | |
470 | || dev->power.runtime_status == RPM_SUSPENDED | |
471 | || dev->power.runtime_status == RPM_SUSPENDING) | |
472 | retval = -EAGAIN; | |
473 | else if (!pm_children_suspended(dev)) | |
474 | retval = -EBUSY; | |
475 | if (retval) | |
476 | return retval; | |
477 | ||
478 | if (dev->power.request_pending) { | |
479 | /* Any requests other then RPM_REQ_IDLE take precedence. */ | |
480 | if (dev->power.request == RPM_REQ_NONE) | |
481 | dev->power.request = RPM_REQ_IDLE; | |
482 | else if (dev->power.request != RPM_REQ_IDLE) | |
483 | retval = -EAGAIN; | |
484 | return retval; | |
485 | } | |
486 | ||
487 | dev->power.request = RPM_REQ_IDLE; | |
488 | dev->power.request_pending = true; | |
489 | queue_work(pm_wq, &dev->power.work); | |
490 | ||
491 | return retval; | |
492 | } | |
493 | ||
494 | /** | |
495 | * pm_request_idle - Submit an idle notification request for given device. | |
496 | * @dev: Device to handle. | |
497 | */ | |
498 | int pm_request_idle(struct device *dev) | |
499 | { | |
500 | unsigned long flags; | |
501 | int retval; | |
502 | ||
503 | spin_lock_irqsave(&dev->power.lock, flags); | |
504 | retval = __pm_request_idle(dev); | |
505 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
506 | ||
507 | return retval; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(pm_request_idle); | |
510 | ||
511 | /** | |
512 | * __pm_request_suspend - Submit a suspend request for given device. | |
513 | * @dev: Device to suspend. | |
514 | * | |
515 | * This function must be called under dev->power.lock with interrupts disabled. | |
516 | */ | |
517 | static int __pm_request_suspend(struct device *dev) | |
518 | { | |
519 | int retval = 0; | |
520 | ||
521 | if (dev->power.runtime_error) | |
522 | return -EINVAL; | |
523 | ||
524 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
525 | retval = 1; | |
526 | else if (atomic_read(&dev->power.usage_count) > 0 | |
527 | || dev->power.disable_depth > 0) | |
528 | retval = -EAGAIN; | |
529 | else if (dev->power.runtime_status == RPM_SUSPENDING) | |
530 | retval = -EINPROGRESS; | |
531 | else if (!pm_children_suspended(dev)) | |
532 | retval = -EBUSY; | |
533 | if (retval < 0) | |
534 | return retval; | |
535 | ||
536 | pm_runtime_deactivate_timer(dev); | |
537 | ||
538 | if (dev->power.request_pending) { | |
539 | /* | |
540 | * Pending resume requests take precedence over us, but we can | |
541 | * overtake any other pending request. | |
542 | */ | |
543 | if (dev->power.request == RPM_REQ_RESUME) | |
544 | retval = -EAGAIN; | |
545 | else if (dev->power.request != RPM_REQ_SUSPEND) | |
546 | dev->power.request = retval ? | |
547 | RPM_REQ_NONE : RPM_REQ_SUSPEND; | |
548 | return retval; | |
549 | } else if (retval) { | |
550 | return retval; | |
551 | } | |
552 | ||
553 | dev->power.request = RPM_REQ_SUSPEND; | |
554 | dev->power.request_pending = true; | |
555 | queue_work(pm_wq, &dev->power.work); | |
556 | ||
557 | return 0; | |
558 | } | |
559 | ||
560 | /** | |
561 | * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). | |
562 | * @data: Device pointer passed by pm_schedule_suspend(). | |
563 | * | |
564 | * Check if the time is right and execute __pm_request_suspend() in that case. | |
565 | */ | |
566 | static void pm_suspend_timer_fn(unsigned long data) | |
567 | { | |
568 | struct device *dev = (struct device *)data; | |
569 | unsigned long flags; | |
570 | unsigned long expires; | |
571 | ||
572 | spin_lock_irqsave(&dev->power.lock, flags); | |
573 | ||
574 | expires = dev->power.timer_expires; | |
575 | /* If 'expire' is after 'jiffies' we've been called too early. */ | |
576 | if (expires > 0 && !time_after(expires, jiffies)) { | |
577 | dev->power.timer_expires = 0; | |
578 | __pm_request_suspend(dev); | |
579 | } | |
580 | ||
581 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
582 | } | |
583 | ||
584 | /** | |
585 | * pm_schedule_suspend - Set up a timer to submit a suspend request in future. | |
586 | * @dev: Device to suspend. | |
587 | * @delay: Time to wait before submitting a suspend request, in milliseconds. | |
588 | */ | |
589 | int pm_schedule_suspend(struct device *dev, unsigned int delay) | |
590 | { | |
591 | unsigned long flags; | |
592 | int retval = 0; | |
593 | ||
594 | spin_lock_irqsave(&dev->power.lock, flags); | |
595 | ||
596 | if (dev->power.runtime_error) { | |
597 | retval = -EINVAL; | |
598 | goto out; | |
599 | } | |
600 | ||
601 | if (!delay) { | |
602 | retval = __pm_request_suspend(dev); | |
603 | goto out; | |
604 | } | |
605 | ||
606 | pm_runtime_deactivate_timer(dev); | |
607 | ||
608 | if (dev->power.request_pending) { | |
609 | /* | |
610 | * Pending resume requests take precedence over us, but any | |
611 | * other pending requests have to be canceled. | |
612 | */ | |
613 | if (dev->power.request == RPM_REQ_RESUME) { | |
614 | retval = -EAGAIN; | |
615 | goto out; | |
616 | } | |
617 | dev->power.request = RPM_REQ_NONE; | |
618 | } | |
619 | ||
620 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
621 | retval = 1; | |
622 | else if (dev->power.runtime_status == RPM_SUSPENDING) | |
623 | retval = -EINPROGRESS; | |
624 | else if (atomic_read(&dev->power.usage_count) > 0 | |
625 | || dev->power.disable_depth > 0) | |
626 | retval = -EAGAIN; | |
627 | else if (!pm_children_suspended(dev)) | |
628 | retval = -EBUSY; | |
629 | if (retval) | |
630 | goto out; | |
631 | ||
632 | dev->power.timer_expires = jiffies + msecs_to_jiffies(delay); | |
633 | mod_timer(&dev->power.suspend_timer, dev->power.timer_expires); | |
634 | ||
635 | out: | |
636 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
637 | ||
638 | return retval; | |
639 | } | |
640 | EXPORT_SYMBOL_GPL(pm_schedule_suspend); | |
641 | ||
642 | /** | |
643 | * pm_request_resume - Submit a resume request for given device. | |
644 | * @dev: Device to resume. | |
645 | * | |
646 | * This function must be called under dev->power.lock with interrupts disabled. | |
647 | */ | |
648 | static int __pm_request_resume(struct device *dev) | |
649 | { | |
650 | int retval = 0; | |
651 | ||
652 | if (dev->power.runtime_error) | |
653 | return -EINVAL; | |
654 | ||
655 | if (dev->power.runtime_status == RPM_ACTIVE) | |
656 | retval = 1; | |
657 | else if (dev->power.runtime_status == RPM_RESUMING) | |
658 | retval = -EINPROGRESS; | |
659 | else if (dev->power.disable_depth > 0) | |
660 | retval = -EAGAIN; | |
661 | if (retval < 0) | |
662 | return retval; | |
663 | ||
664 | pm_runtime_deactivate_timer(dev); | |
665 | ||
666 | if (dev->power.request_pending) { | |
667 | /* If non-resume request is pending, we can overtake it. */ | |
668 | dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME; | |
669 | return retval; | |
670 | } else if (retval) { | |
671 | return retval; | |
672 | } | |
673 | ||
674 | dev->power.request = RPM_REQ_RESUME; | |
675 | dev->power.request_pending = true; | |
676 | queue_work(pm_wq, &dev->power.work); | |
677 | ||
678 | return retval; | |
679 | } | |
680 | ||
681 | /** | |
682 | * pm_request_resume - Submit a resume request for given device. | |
683 | * @dev: Device to resume. | |
684 | */ | |
685 | int pm_request_resume(struct device *dev) | |
686 | { | |
687 | unsigned long flags; | |
688 | int retval; | |
689 | ||
690 | spin_lock_irqsave(&dev->power.lock, flags); | |
691 | retval = __pm_request_resume(dev); | |
692 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
693 | ||
694 | return retval; | |
695 | } | |
696 | EXPORT_SYMBOL_GPL(pm_request_resume); | |
697 | ||
698 | /** | |
699 | * __pm_runtime_get - Reference count a device and wake it up, if necessary. | |
700 | * @dev: Device to handle. | |
701 | * @sync: If set and the device is suspended, resume it synchronously. | |
702 | * | |
703 | * Increment the usage count of the device and if it was zero previously, | |
704 | * resume it or submit a resume request for it, depending on the value of @sync. | |
705 | */ | |
706 | int __pm_runtime_get(struct device *dev, bool sync) | |
707 | { | |
708 | int retval = 1; | |
709 | ||
710 | if (atomic_add_return(1, &dev->power.usage_count) == 1) | |
711 | retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); | |
712 | ||
713 | return retval; | |
714 | } | |
715 | EXPORT_SYMBOL_GPL(__pm_runtime_get); | |
716 | ||
717 | /** | |
718 | * __pm_runtime_put - Decrement the device's usage counter and notify its bus. | |
719 | * @dev: Device to handle. | |
720 | * @sync: If the device's bus type is to be notified, do that synchronously. | |
721 | * | |
722 | * Decrement the usage count of the device and if it reaches zero, carry out a | |
723 | * synchronous idle notification or submit an idle notification request for it, | |
724 | * depending on the value of @sync. | |
725 | */ | |
726 | int __pm_runtime_put(struct device *dev, bool sync) | |
727 | { | |
728 | int retval = 0; | |
729 | ||
730 | if (atomic_dec_and_test(&dev->power.usage_count)) | |
731 | retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev); | |
732 | ||
733 | return retval; | |
734 | } | |
735 | EXPORT_SYMBOL_GPL(__pm_runtime_put); | |
736 | ||
737 | /** | |
738 | * __pm_runtime_set_status - Set run-time PM status of a device. | |
739 | * @dev: Device to handle. | |
740 | * @status: New run-time PM status of the device. | |
741 | * | |
742 | * If run-time PM of the device is disabled or its power.runtime_error field is | |
743 | * different from zero, the status may be changed either to RPM_ACTIVE, or to | |
744 | * RPM_SUSPENDED, as long as that reflects the actual state of the device. | |
745 | * However, if the device has a parent and the parent is not active, and the | |
746 | * parent's power.ignore_children flag is unset, the device's status cannot be | |
747 | * set to RPM_ACTIVE, so -EBUSY is returned in that case. | |
748 | * | |
749 | * If successful, __pm_runtime_set_status() clears the power.runtime_error field | |
750 | * and the device parent's counter of unsuspended children is modified to | |
751 | * reflect the new status. If the new status is RPM_SUSPENDED, an idle | |
752 | * notification request for the parent is submitted. | |
753 | */ | |
754 | int __pm_runtime_set_status(struct device *dev, unsigned int status) | |
755 | { | |
756 | struct device *parent = dev->parent; | |
757 | unsigned long flags; | |
758 | bool notify_parent = false; | |
759 | int error = 0; | |
760 | ||
761 | if (status != RPM_ACTIVE && status != RPM_SUSPENDED) | |
762 | return -EINVAL; | |
763 | ||
764 | spin_lock_irqsave(&dev->power.lock, flags); | |
765 | ||
766 | if (!dev->power.runtime_error && !dev->power.disable_depth) { | |
767 | error = -EAGAIN; | |
768 | goto out; | |
769 | } | |
770 | ||
771 | if (dev->power.runtime_status == status) | |
772 | goto out_set; | |
773 | ||
774 | if (status == RPM_SUSPENDED) { | |
775 | /* It always is possible to set the status to 'suspended'. */ | |
776 | if (parent) { | |
777 | atomic_add_unless(&parent->power.child_count, -1, 0); | |
778 | notify_parent = !parent->power.ignore_children; | |
779 | } | |
780 | goto out_set; | |
781 | } | |
782 | ||
783 | if (parent) { | |
784 | spin_lock_irq(&parent->power.lock); | |
785 | ||
786 | /* | |
787 | * It is invalid to put an active child under a parent that is | |
788 | * not active, has run-time PM enabled and the | |
789 | * 'power.ignore_children' flag unset. | |
790 | */ | |
791 | if (!parent->power.disable_depth | |
792 | && !parent->power.ignore_children | |
793 | && parent->power.runtime_status != RPM_ACTIVE) { | |
794 | error = -EBUSY; | |
795 | } else { | |
796 | if (dev->power.runtime_status == RPM_SUSPENDED) | |
797 | atomic_inc(&parent->power.child_count); | |
798 | } | |
799 | ||
800 | spin_unlock_irq(&parent->power.lock); | |
801 | ||
802 | if (error) | |
803 | goto out; | |
804 | } | |
805 | ||
806 | out_set: | |
807 | dev->power.runtime_status = status; | |
808 | dev->power.runtime_error = 0; | |
809 | out: | |
810 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
811 | ||
812 | if (notify_parent) | |
813 | pm_request_idle(parent); | |
814 | ||
815 | return error; | |
816 | } | |
817 | EXPORT_SYMBOL_GPL(__pm_runtime_set_status); | |
818 | ||
819 | /** | |
820 | * __pm_runtime_barrier - Cancel pending requests and wait for completions. | |
821 | * @dev: Device to handle. | |
822 | * | |
823 | * Flush all pending requests for the device from pm_wq and wait for all | |
824 | * run-time PM operations involving the device in progress to complete. | |
825 | * | |
826 | * Should be called under dev->power.lock with interrupts disabled. | |
827 | */ | |
828 | static void __pm_runtime_barrier(struct device *dev) | |
829 | { | |
830 | pm_runtime_deactivate_timer(dev); | |
831 | ||
832 | if (dev->power.request_pending) { | |
833 | dev->power.request = RPM_REQ_NONE; | |
834 | spin_unlock_irq(&dev->power.lock); | |
835 | ||
836 | cancel_work_sync(&dev->power.work); | |
837 | ||
838 | spin_lock_irq(&dev->power.lock); | |
839 | dev->power.request_pending = false; | |
840 | } | |
841 | ||
842 | if (dev->power.runtime_status == RPM_SUSPENDING | |
843 | || dev->power.runtime_status == RPM_RESUMING | |
844 | || dev->power.idle_notification) { | |
845 | DEFINE_WAIT(wait); | |
846 | ||
847 | /* Suspend, wake-up or idle notification in progress. */ | |
848 | for (;;) { | |
849 | prepare_to_wait(&dev->power.wait_queue, &wait, | |
850 | TASK_UNINTERRUPTIBLE); | |
851 | if (dev->power.runtime_status != RPM_SUSPENDING | |
852 | && dev->power.runtime_status != RPM_RESUMING | |
853 | && !dev->power.idle_notification) | |
854 | break; | |
855 | spin_unlock_irq(&dev->power.lock); | |
856 | ||
857 | schedule(); | |
858 | ||
859 | spin_lock_irq(&dev->power.lock); | |
860 | } | |
861 | finish_wait(&dev->power.wait_queue, &wait); | |
862 | } | |
863 | } | |
864 | ||
865 | /** | |
866 | * pm_runtime_barrier - Flush pending requests and wait for completions. | |
867 | * @dev: Device to handle. | |
868 | * | |
869 | * Prevent the device from being suspended by incrementing its usage counter and | |
870 | * if there's a pending resume request for the device, wake the device up. | |
871 | * Next, make sure that all pending requests for the device have been flushed | |
872 | * from pm_wq and wait for all run-time PM operations involving the device in | |
873 | * progress to complete. | |
874 | * | |
875 | * Return value: | |
876 | * 1, if there was a resume request pending and the device had to be woken up, | |
877 | * 0, otherwise | |
878 | */ | |
879 | int pm_runtime_barrier(struct device *dev) | |
880 | { | |
881 | int retval = 0; | |
882 | ||
883 | pm_runtime_get_noresume(dev); | |
884 | spin_lock_irq(&dev->power.lock); | |
885 | ||
886 | if (dev->power.request_pending | |
887 | && dev->power.request == RPM_REQ_RESUME) { | |
888 | __pm_runtime_resume(dev, false); | |
889 | retval = 1; | |
890 | } | |
891 | ||
892 | __pm_runtime_barrier(dev); | |
893 | ||
894 | spin_unlock_irq(&dev->power.lock); | |
895 | pm_runtime_put_noidle(dev); | |
896 | ||
897 | return retval; | |
898 | } | |
899 | EXPORT_SYMBOL_GPL(pm_runtime_barrier); | |
900 | ||
901 | /** | |
902 | * __pm_runtime_disable - Disable run-time PM of a device. | |
903 | * @dev: Device to handle. | |
904 | * @check_resume: If set, check if there's a resume request for the device. | |
905 | * | |
906 | * Increment power.disable_depth for the device and if was zero previously, | |
907 | * cancel all pending run-time PM requests for the device and wait for all | |
908 | * operations in progress to complete. The device can be either active or | |
909 | * suspended after its run-time PM has been disabled. | |
910 | * | |
911 | * If @check_resume is set and there's a resume request pending when | |
912 | * __pm_runtime_disable() is called and power.disable_depth is zero, the | |
913 | * function will wake up the device before disabling its run-time PM. | |
914 | */ | |
915 | void __pm_runtime_disable(struct device *dev, bool check_resume) | |
916 | { | |
917 | spin_lock_irq(&dev->power.lock); | |
918 | ||
919 | if (dev->power.disable_depth > 0) { | |
920 | dev->power.disable_depth++; | |
921 | goto out; | |
922 | } | |
923 | ||
924 | /* | |
925 | * Wake up the device if there's a resume request pending, because that | |
926 | * means there probably is some I/O to process and disabling run-time PM | |
927 | * shouldn't prevent the device from processing the I/O. | |
928 | */ | |
929 | if (check_resume && dev->power.request_pending | |
930 | && dev->power.request == RPM_REQ_RESUME) { | |
931 | /* | |
932 | * Prevent suspends and idle notifications from being carried | |
933 | * out after we have woken up the device. | |
934 | */ | |
935 | pm_runtime_get_noresume(dev); | |
936 | ||
937 | __pm_runtime_resume(dev, false); | |
938 | ||
939 | pm_runtime_put_noidle(dev); | |
940 | } | |
941 | ||
942 | if (!dev->power.disable_depth++) | |
943 | __pm_runtime_barrier(dev); | |
944 | ||
945 | out: | |
946 | spin_unlock_irq(&dev->power.lock); | |
947 | } | |
948 | EXPORT_SYMBOL_GPL(__pm_runtime_disable); | |
949 | ||
950 | /** | |
951 | * pm_runtime_enable - Enable run-time PM of a device. | |
952 | * @dev: Device to handle. | |
953 | */ | |
954 | void pm_runtime_enable(struct device *dev) | |
955 | { | |
956 | unsigned long flags; | |
957 | ||
958 | spin_lock_irqsave(&dev->power.lock, flags); | |
959 | ||
960 | if (dev->power.disable_depth > 0) | |
961 | dev->power.disable_depth--; | |
962 | else | |
963 | dev_warn(dev, "Unbalanced %s!\n", __func__); | |
964 | ||
965 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
966 | } | |
967 | EXPORT_SYMBOL_GPL(pm_runtime_enable); | |
968 | ||
969 | /** | |
970 | * pm_runtime_init - Initialize run-time PM fields in given device object. | |
971 | * @dev: Device object to initialize. | |
972 | */ | |
973 | void pm_runtime_init(struct device *dev) | |
974 | { | |
975 | spin_lock_init(&dev->power.lock); | |
976 | ||
977 | dev->power.runtime_status = RPM_SUSPENDED; | |
978 | dev->power.idle_notification = false; | |
979 | ||
980 | dev->power.disable_depth = 1; | |
981 | atomic_set(&dev->power.usage_count, 0); | |
982 | ||
983 | dev->power.runtime_error = 0; | |
984 | ||
985 | atomic_set(&dev->power.child_count, 0); | |
986 | pm_suspend_ignore_children(dev, false); | |
987 | ||
988 | dev->power.request_pending = false; | |
989 | dev->power.request = RPM_REQ_NONE; | |
990 | dev->power.deferred_resume = false; | |
991 | INIT_WORK(&dev->power.work, pm_runtime_work); | |
992 | ||
993 | dev->power.timer_expires = 0; | |
994 | setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn, | |
995 | (unsigned long)dev); | |
996 | ||
997 | init_waitqueue_head(&dev->power.wait_queue); | |
998 | } | |
999 | ||
1000 | /** | |
1001 | * pm_runtime_remove - Prepare for removing a device from device hierarchy. | |
1002 | * @dev: Device object being removed from device hierarchy. | |
1003 | */ | |
1004 | void pm_runtime_remove(struct device *dev) | |
1005 | { | |
1006 | __pm_runtime_disable(dev, false); | |
1007 | ||
1008 | /* Change the status back to 'suspended' to match the initial status. */ | |
1009 | if (dev->power.runtime_status == RPM_ACTIVE) | |
1010 | pm_runtime_set_suspended(dev); | |
1011 | } |