2 * drivers/base/power/main.c - Where the driver meets power management.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
7 * This file is released under the GPLv2
10 * The driver model core calls device_pm_add() when a device is registered.
11 * This will initialize the embedded device_pm_info object in the device
12 * and add it to the list of power-controlled devices. sysfs entries for
13 * controlling device power management will also be added.
15 * A separate list is used for keeping track of power info, because the power
16 * domain dependencies may differ from the ancestral dependencies that the
17 * subsystem list maintains.
20 #include <linux/device.h>
21 #include <linux/kallsyms.h>
22 #include <linux/mutex.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/resume-trace.h>
26 #include <linux/interrupt.h>
27 #include <linux/sched.h>
28 #include <linux/async.h>
29 #include <linux/suspend.h>
35 * The entries in the dpm_list list are in a depth first order, simply
36 * because children are guaranteed to be discovered after parents, and
37 * are inserted at the back of the list on discovery.
39 * Since device_pm_add() may be called with a device lock held,
40 * we must never try to acquire a device lock while holding
45 LIST_HEAD(dpm_prepared_list);
46 LIST_HEAD(dpm_suspended_list);
47 LIST_HEAD(dpm_noirq_list);
49 static DEFINE_MUTEX(dpm_list_mtx);
50 static pm_message_t pm_transition;
52 static int async_error;
55 * device_pm_init - Initialize the PM-related part of a device object.
56 * @dev: Device object being initialized.
58 void device_pm_init(struct device *dev)
60 dev->power.is_prepared = false;
61 dev->power.is_suspended = false;
62 init_completion(&dev->power.completion);
63 complete_all(&dev->power.completion);
64 dev->power.wakeup = NULL;
65 spin_lock_init(&dev->power.lock);
67 INIT_LIST_HEAD(&dev->power.entry);
71 * device_pm_lock - Lock the list of active devices used by the PM core.
73 void device_pm_lock(void)
75 mutex_lock(&dpm_list_mtx);
79 * device_pm_unlock - Unlock the list of active devices used by the PM core.
81 void device_pm_unlock(void)
83 mutex_unlock(&dpm_list_mtx);
87 * device_pm_add - Add a device to the PM core's list of active devices.
88 * @dev: Device to add to the list.
90 void device_pm_add(struct device *dev)
92 pr_debug("PM: Adding info for %s:%s\n",
93 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
94 mutex_lock(&dpm_list_mtx);
95 if (dev->parent && dev->parent->power.is_prepared)
96 dev_warn(dev, "parent %s should not be sleeping\n",
97 dev_name(dev->parent));
98 list_add_tail(&dev->power.entry, &dpm_list);
99 mutex_unlock(&dpm_list_mtx);
103 * device_pm_remove - Remove a device from the PM core's list of active devices.
104 * @dev: Device to be removed from the list.
106 void device_pm_remove(struct device *dev)
108 pr_debug("PM: Removing info for %s:%s\n",
109 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
110 complete_all(&dev->power.completion);
111 mutex_lock(&dpm_list_mtx);
112 list_del_init(&dev->power.entry);
113 mutex_unlock(&dpm_list_mtx);
114 device_wakeup_disable(dev);
115 pm_runtime_remove(dev);
119 * device_pm_move_before - Move device in the PM core's list of active devices.
120 * @deva: Device to move in dpm_list.
121 * @devb: Device @deva should come before.
123 void device_pm_move_before(struct device *deva, struct device *devb)
125 pr_debug("PM: Moving %s:%s before %s:%s\n",
126 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
127 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
128 /* Delete deva from dpm_list and reinsert before devb. */
129 list_move_tail(&deva->power.entry, &devb->power.entry);
133 * device_pm_move_after - Move device in the PM core's list of active devices.
134 * @deva: Device to move in dpm_list.
135 * @devb: Device @deva should come after.
137 void device_pm_move_after(struct device *deva, struct device *devb)
139 pr_debug("PM: Moving %s:%s after %s:%s\n",
140 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
141 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
142 /* Delete deva from dpm_list and reinsert after devb. */
143 list_move(&deva->power.entry, &devb->power.entry);
147 * device_pm_move_last - Move device to end of the PM core's list of devices.
148 * @dev: Device to move in dpm_list.
150 void device_pm_move_last(struct device *dev)
152 pr_debug("PM: Moving %s:%s to end of list\n",
153 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
154 list_move_tail(&dev->power.entry, &dpm_list);
157 static ktime_t initcall_debug_start(struct device *dev)
159 ktime_t calltime = ktime_set(0, 0);
161 if (initcall_debug) {
162 pr_info("calling %s+ @ %i\n",
163 dev_name(dev), task_pid_nr(current));
164 calltime = ktime_get();
170 static void initcall_debug_report(struct device *dev, ktime_t calltime,
173 ktime_t delta, rettime;
175 if (initcall_debug) {
176 rettime = ktime_get();
177 delta = ktime_sub(rettime, calltime);
178 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
179 error, (unsigned long long)ktime_to_ns(delta) >> 10);
184 * dpm_wait - Wait for a PM operation to complete.
185 * @dev: Device to wait for.
186 * @async: If unset, wait only if the device's power.async_suspend flag is set.
188 static void dpm_wait(struct device *dev, bool async)
193 if (async || (pm_async_enabled && dev->power.async_suspend))
194 wait_for_completion(&dev->power.completion);
197 static int dpm_wait_fn(struct device *dev, void *async_ptr)
199 dpm_wait(dev, *((bool *)async_ptr));
203 static void dpm_wait_for_children(struct device *dev, bool async)
205 device_for_each_child(dev, &async, dpm_wait_fn);
209 * pm_op - Execute the PM operation appropriate for given PM event.
210 * @dev: Device to handle.
211 * @ops: PM operations to choose from.
212 * @state: PM transition of the system being carried out.
214 static int pm_op(struct device *dev,
215 const struct dev_pm_ops *ops,
221 calltime = initcall_debug_start(dev);
223 switch (state.event) {
224 #ifdef CONFIG_SUSPEND
225 case PM_EVENT_SUSPEND:
227 error = ops->suspend(dev);
228 suspend_report_result(ops->suspend, error);
231 case PM_EVENT_RESUME:
233 error = ops->resume(dev);
234 suspend_report_result(ops->resume, error);
237 #endif /* CONFIG_SUSPEND */
238 #ifdef CONFIG_HIBERNATE_CALLBACKS
239 case PM_EVENT_FREEZE:
240 case PM_EVENT_QUIESCE:
242 error = ops->freeze(dev);
243 suspend_report_result(ops->freeze, error);
246 case PM_EVENT_HIBERNATE:
248 error = ops->poweroff(dev);
249 suspend_report_result(ops->poweroff, error);
253 case PM_EVENT_RECOVER:
255 error = ops->thaw(dev);
256 suspend_report_result(ops->thaw, error);
259 case PM_EVENT_RESTORE:
261 error = ops->restore(dev);
262 suspend_report_result(ops->restore, error);
265 #endif /* CONFIG_HIBERNATE_CALLBACKS */
270 initcall_debug_report(dev, calltime, error);
276 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
277 * @dev: Device to handle.
278 * @ops: PM operations to choose from.
279 * @state: PM transition of the system being carried out.
281 * The driver of @dev will not receive interrupts while this function is being
284 static int pm_noirq_op(struct device *dev,
285 const struct dev_pm_ops *ops,
289 ktime_t calltime = ktime_set(0, 0), delta, rettime;
291 if (initcall_debug) {
292 pr_info("calling %s+ @ %i, parent: %s\n",
293 dev_name(dev), task_pid_nr(current),
294 dev->parent ? dev_name(dev->parent) : "none");
295 calltime = ktime_get();
298 switch (state.event) {
299 #ifdef CONFIG_SUSPEND
300 case PM_EVENT_SUSPEND:
301 if (ops->suspend_noirq) {
302 error = ops->suspend_noirq(dev);
303 suspend_report_result(ops->suspend_noirq, error);
306 case PM_EVENT_RESUME:
307 if (ops->resume_noirq) {
308 error = ops->resume_noirq(dev);
309 suspend_report_result(ops->resume_noirq, error);
312 #endif /* CONFIG_SUSPEND */
313 #ifdef CONFIG_HIBERNATE_CALLBACKS
314 case PM_EVENT_FREEZE:
315 case PM_EVENT_QUIESCE:
316 if (ops->freeze_noirq) {
317 error = ops->freeze_noirq(dev);
318 suspend_report_result(ops->freeze_noirq, error);
321 case PM_EVENT_HIBERNATE:
322 if (ops->poweroff_noirq) {
323 error = ops->poweroff_noirq(dev);
324 suspend_report_result(ops->poweroff_noirq, error);
328 case PM_EVENT_RECOVER:
329 if (ops->thaw_noirq) {
330 error = ops->thaw_noirq(dev);
331 suspend_report_result(ops->thaw_noirq, error);
334 case PM_EVENT_RESTORE:
335 if (ops->restore_noirq) {
336 error = ops->restore_noirq(dev);
337 suspend_report_result(ops->restore_noirq, error);
340 #endif /* CONFIG_HIBERNATE_CALLBACKS */
345 if (initcall_debug) {
346 rettime = ktime_get();
347 delta = ktime_sub(rettime, calltime);
348 printk("initcall %s_i+ returned %d after %Ld usecs\n",
349 dev_name(dev), error,
350 (unsigned long long)ktime_to_ns(delta) >> 10);
356 static char *pm_verb(int event)
359 case PM_EVENT_SUSPEND:
361 case PM_EVENT_RESUME:
363 case PM_EVENT_FREEZE:
365 case PM_EVENT_QUIESCE:
367 case PM_EVENT_HIBERNATE:
371 case PM_EVENT_RESTORE:
373 case PM_EVENT_RECOVER:
376 return "(unknown PM event)";
380 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
382 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
383 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
384 ", may wakeup" : "");
387 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
390 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
391 dev_name(dev), pm_verb(state.event), info, error);
394 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
400 calltime = ktime_get();
401 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
402 do_div(usecs64, NSEC_PER_USEC);
406 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
407 info ?: "", info ? " " : "", pm_verb(state.event),
408 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
411 /*------------------------- Resume routines -------------------------*/
414 * device_resume_noirq - Execute an "early resume" callback for given device.
415 * @dev: Device to handle.
416 * @state: PM transition of the system being carried out.
418 * The driver of @dev will not receive interrupts while this function is being
421 static int device_resume_noirq(struct device *dev, pm_message_t state)
428 if (dev->pm_domain) {
429 pm_dev_dbg(dev, state, "EARLY power domain ");
430 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
431 } else if (dev->type && dev->type->pm) {
432 pm_dev_dbg(dev, state, "EARLY type ");
433 error = pm_noirq_op(dev, dev->type->pm, state);
434 } else if (dev->class && dev->class->pm) {
435 pm_dev_dbg(dev, state, "EARLY class ");
436 error = pm_noirq_op(dev, dev->class->pm, state);
437 } else if (dev->bus && dev->bus->pm) {
438 pm_dev_dbg(dev, state, "EARLY ");
439 error = pm_noirq_op(dev, dev->bus->pm, state);
447 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
448 * @state: PM transition of the system being carried out.
450 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
451 * enable device drivers to receive interrupts.
453 void dpm_resume_noirq(pm_message_t state)
455 ktime_t starttime = ktime_get();
457 mutex_lock(&dpm_list_mtx);
458 while (!list_empty(&dpm_noirq_list)) {
459 struct device *dev = to_device(dpm_noirq_list.next);
463 list_move_tail(&dev->power.entry, &dpm_suspended_list);
464 mutex_unlock(&dpm_list_mtx);
466 error = device_resume_noirq(dev, state);
468 pm_dev_err(dev, state, " early", error);
470 mutex_lock(&dpm_list_mtx);
473 mutex_unlock(&dpm_list_mtx);
474 dpm_show_time(starttime, state, "early");
475 resume_device_irqs();
477 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
480 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
481 * @dev: Device to resume.
482 * @cb: Resume callback to execute.
484 static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
489 calltime = initcall_debug_start(dev);
492 suspend_report_result(cb, error);
494 initcall_debug_report(dev, calltime, error);
500 * device_resume - Execute "resume" callbacks for given device.
501 * @dev: Device to handle.
502 * @state: PM transition of the system being carried out.
503 * @async: If true, the device is being resumed asynchronously.
505 static int device_resume(struct device *dev, pm_message_t state, bool async)
513 dpm_wait(dev->parent, async);
517 * This is a fib. But we'll allow new children to be added below
518 * a resumed device, even if the device hasn't been completed yet.
520 dev->power.is_prepared = false;
522 if (!dev->power.is_suspended)
525 pm_runtime_enable(dev);
528 if (dev->pm_domain) {
529 pm_dev_dbg(dev, state, "power domain ");
530 error = pm_op(dev, &dev->pm_domain->ops, state);
534 if (dev->type && dev->type->pm) {
535 pm_dev_dbg(dev, state, "type ");
536 error = pm_op(dev, dev->type->pm, state);
541 if (dev->class->pm) {
542 pm_dev_dbg(dev, state, "class ");
543 error = pm_op(dev, dev->class->pm, state);
545 } else if (dev->class->resume) {
546 pm_dev_dbg(dev, state, "legacy class ");
547 error = legacy_resume(dev, dev->class->resume);
554 pm_dev_dbg(dev, state, "");
555 error = pm_op(dev, dev->bus->pm, state);
556 } else if (dev->bus->resume) {
557 pm_dev_dbg(dev, state, "legacy ");
558 error = legacy_resume(dev, dev->bus->resume);
563 dev->power.is_suspended = false;
567 complete_all(&dev->power.completion);
572 pm_runtime_put_sync(dev);
577 static void async_resume(void *data, async_cookie_t cookie)
579 struct device *dev = (struct device *)data;
582 error = device_resume(dev, pm_transition, true);
584 pm_dev_err(dev, pm_transition, " async", error);
588 static bool is_async(struct device *dev)
590 return dev->power.async_suspend && pm_async_enabled
591 && !pm_trace_is_enabled();
595 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
596 * @state: PM transition of the system being carried out.
598 * Execute the appropriate "resume" callback for all devices whose status
599 * indicates that they are suspended.
601 void dpm_resume(pm_message_t state)
604 ktime_t starttime = ktime_get();
608 mutex_lock(&dpm_list_mtx);
609 pm_transition = state;
612 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
613 INIT_COMPLETION(dev->power.completion);
616 async_schedule(async_resume, dev);
620 while (!list_empty(&dpm_suspended_list)) {
621 dev = to_device(dpm_suspended_list.next);
623 if (!is_async(dev)) {
626 mutex_unlock(&dpm_list_mtx);
628 error = device_resume(dev, state, false);
630 pm_dev_err(dev, state, "", error);
632 mutex_lock(&dpm_list_mtx);
634 if (!list_empty(&dev->power.entry))
635 list_move_tail(&dev->power.entry, &dpm_prepared_list);
638 mutex_unlock(&dpm_list_mtx);
639 async_synchronize_full();
640 dpm_show_time(starttime, state, NULL);
644 * device_complete - Complete a PM transition for given device.
645 * @dev: Device to handle.
646 * @state: PM transition of the system being carried out.
648 static void device_complete(struct device *dev, pm_message_t state)
652 if (dev->pm_domain) {
653 pm_dev_dbg(dev, state, "completing power domain ");
654 if (dev->pm_domain->ops.complete)
655 dev->pm_domain->ops.complete(dev);
656 } else if (dev->type && dev->type->pm) {
657 pm_dev_dbg(dev, state, "completing type ");
658 if (dev->type->pm->complete)
659 dev->type->pm->complete(dev);
660 } else if (dev->class && dev->class->pm) {
661 pm_dev_dbg(dev, state, "completing class ");
662 if (dev->class->pm->complete)
663 dev->class->pm->complete(dev);
664 } else if (dev->bus && dev->bus->pm) {
665 pm_dev_dbg(dev, state, "completing ");
666 if (dev->bus->pm->complete)
667 dev->bus->pm->complete(dev);
674 * dpm_complete - Complete a PM transition for all non-sysdev devices.
675 * @state: PM transition of the system being carried out.
677 * Execute the ->complete() callbacks for all devices whose PM status is not
678 * DPM_ON (this allows new devices to be registered).
680 void dpm_complete(pm_message_t state)
682 struct list_head list;
686 INIT_LIST_HEAD(&list);
687 mutex_lock(&dpm_list_mtx);
688 while (!list_empty(&dpm_prepared_list)) {
689 struct device *dev = to_device(dpm_prepared_list.prev);
692 dev->power.is_prepared = false;
693 list_move(&dev->power.entry, &list);
694 mutex_unlock(&dpm_list_mtx);
696 device_complete(dev, state);
698 mutex_lock(&dpm_list_mtx);
701 list_splice(&list, &dpm_list);
702 mutex_unlock(&dpm_list_mtx);
706 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
707 * @state: PM transition of the system being carried out.
709 * Execute "resume" callbacks for all devices and complete the PM transition of
712 void dpm_resume_end(pm_message_t state)
717 EXPORT_SYMBOL_GPL(dpm_resume_end);
720 /*------------------------- Suspend routines -------------------------*/
723 * resume_event - Return a "resume" message for given "suspend" sleep state.
724 * @sleep_state: PM message representing a sleep state.
726 * Return a PM message representing the resume event corresponding to given
729 static pm_message_t resume_event(pm_message_t sleep_state)
731 switch (sleep_state.event) {
732 case PM_EVENT_SUSPEND:
734 case PM_EVENT_FREEZE:
735 case PM_EVENT_QUIESCE:
737 case PM_EVENT_HIBERNATE:
744 * device_suspend_noirq - Execute a "late suspend" callback for given device.
745 * @dev: Device to handle.
746 * @state: PM transition of the system being carried out.
748 * The driver of @dev will not receive interrupts while this function is being
751 static int device_suspend_noirq(struct device *dev, pm_message_t state)
755 if (dev->pm_domain) {
756 pm_dev_dbg(dev, state, "LATE power domain ");
757 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
760 } else if (dev->type && dev->type->pm) {
761 pm_dev_dbg(dev, state, "LATE type ");
762 error = pm_noirq_op(dev, dev->type->pm, state);
765 } else if (dev->class && dev->class->pm) {
766 pm_dev_dbg(dev, state, "LATE class ");
767 error = pm_noirq_op(dev, dev->class->pm, state);
770 } else if (dev->bus && dev->bus->pm) {
771 pm_dev_dbg(dev, state, "LATE ");
772 error = pm_noirq_op(dev, dev->bus->pm, state);
781 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
782 * @state: PM transition of the system being carried out.
784 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
785 * handlers for all non-sysdev devices.
787 int dpm_suspend_noirq(pm_message_t state)
789 ktime_t starttime = ktime_get();
792 suspend_device_irqs();
793 mutex_lock(&dpm_list_mtx);
794 while (!list_empty(&dpm_suspended_list)) {
795 struct device *dev = to_device(dpm_suspended_list.prev);
798 mutex_unlock(&dpm_list_mtx);
800 error = device_suspend_noirq(dev, state);
802 mutex_lock(&dpm_list_mtx);
804 pm_dev_err(dev, state, " late", error);
808 if (!list_empty(&dev->power.entry))
809 list_move(&dev->power.entry, &dpm_noirq_list);
812 mutex_unlock(&dpm_list_mtx);
814 dpm_resume_noirq(resume_event(state));
816 dpm_show_time(starttime, state, "late");
819 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
822 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
823 * @dev: Device to suspend.
824 * @state: PM transition of the system being carried out.
825 * @cb: Suspend callback to execute.
827 static int legacy_suspend(struct device *dev, pm_message_t state,
828 int (*cb)(struct device *dev, pm_message_t state))
833 calltime = initcall_debug_start(dev);
835 error = cb(dev, state);
836 suspend_report_result(cb, error);
838 initcall_debug_report(dev, calltime, error);
844 * device_suspend - Execute "suspend" callbacks for given device.
845 * @dev: Device to handle.
846 * @state: PM transition of the system being carried out.
847 * @async: If true, the device is being suspended asynchronously.
849 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
853 dpm_wait_for_children(dev, async);
858 pm_runtime_get_noresume(dev);
859 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
860 pm_wakeup_event(dev, 0);
862 if (pm_wakeup_pending()) {
863 pm_runtime_put_sync(dev);
864 async_error = -EBUSY;
870 if (dev->pm_domain) {
871 pm_dev_dbg(dev, state, "power domain ");
872 error = pm_op(dev, &dev->pm_domain->ops, state);
876 if (dev->type && dev->type->pm) {
877 pm_dev_dbg(dev, state, "type ");
878 error = pm_op(dev, dev->type->pm, state);
883 if (dev->class->pm) {
884 pm_dev_dbg(dev, state, "class ");
885 error = pm_op(dev, dev->class->pm, state);
887 } else if (dev->class->suspend) {
888 pm_dev_dbg(dev, state, "legacy class ");
889 error = legacy_suspend(dev, state, dev->class->suspend);
896 pm_dev_dbg(dev, state, "");
897 error = pm_op(dev, dev->bus->pm, state);
898 } else if (dev->bus->suspend) {
899 pm_dev_dbg(dev, state, "legacy ");
900 error = legacy_suspend(dev, state, dev->bus->suspend);
905 dev->power.is_suspended = !error;
908 complete_all(&dev->power.completion);
911 pm_runtime_put_sync(dev);
913 } else if (dev->power.is_suspended) {
914 __pm_runtime_disable(dev, false);
920 static void async_suspend(void *data, async_cookie_t cookie)
922 struct device *dev = (struct device *)data;
925 error = __device_suspend(dev, pm_transition, true);
927 pm_dev_err(dev, pm_transition, " async", error);
932 static int device_suspend(struct device *dev)
934 INIT_COMPLETION(dev->power.completion);
936 if (pm_async_enabled && dev->power.async_suspend) {
938 async_schedule(async_suspend, dev);
942 return __device_suspend(dev, pm_transition, false);
946 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
947 * @state: PM transition of the system being carried out.
949 int dpm_suspend(pm_message_t state)
951 ktime_t starttime = ktime_get();
956 mutex_lock(&dpm_list_mtx);
957 pm_transition = state;
959 while (!list_empty(&dpm_prepared_list)) {
960 struct device *dev = to_device(dpm_prepared_list.prev);
963 mutex_unlock(&dpm_list_mtx);
965 error = device_suspend(dev);
967 mutex_lock(&dpm_list_mtx);
969 pm_dev_err(dev, state, "", error);
973 if (!list_empty(&dev->power.entry))
974 list_move(&dev->power.entry, &dpm_suspended_list);
979 mutex_unlock(&dpm_list_mtx);
980 async_synchronize_full();
984 dpm_show_time(starttime, state, NULL);
989 * device_prepare - Prepare a device for system power transition.
990 * @dev: Device to handle.
991 * @state: PM transition of the system being carried out.
993 * Execute the ->prepare() callback(s) for given device. No new children of the
994 * device may be registered after this function has returned.
996 static int device_prepare(struct device *dev, pm_message_t state)
1002 if (dev->pm_domain) {
1003 pm_dev_dbg(dev, state, "preparing power domain ");
1004 if (dev->pm_domain->ops.prepare)
1005 error = dev->pm_domain->ops.prepare(dev);
1006 suspend_report_result(dev->pm_domain->ops.prepare, error);
1009 } else if (dev->type && dev->type->pm) {
1010 pm_dev_dbg(dev, state, "preparing type ");
1011 if (dev->type->pm->prepare)
1012 error = dev->type->pm->prepare(dev);
1013 suspend_report_result(dev->type->pm->prepare, error);
1016 } else if (dev->class && dev->class->pm) {
1017 pm_dev_dbg(dev, state, "preparing class ");
1018 if (dev->class->pm->prepare)
1019 error = dev->class->pm->prepare(dev);
1020 suspend_report_result(dev->class->pm->prepare, error);
1023 } else if (dev->bus && dev->bus->pm) {
1024 pm_dev_dbg(dev, state, "preparing ");
1025 if (dev->bus->pm->prepare)
1026 error = dev->bus->pm->prepare(dev);
1027 suspend_report_result(dev->bus->pm->prepare, error);
1037 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1038 * @state: PM transition of the system being carried out.
1040 * Execute the ->prepare() callback(s) for all devices.
1042 int dpm_prepare(pm_message_t state)
1048 mutex_lock(&dpm_list_mtx);
1049 while (!list_empty(&dpm_list)) {
1050 struct device *dev = to_device(dpm_list.next);
1053 mutex_unlock(&dpm_list_mtx);
1055 error = device_prepare(dev, state);
1057 mutex_lock(&dpm_list_mtx);
1059 if (error == -EAGAIN) {
1064 printk(KERN_INFO "PM: Device %s not prepared "
1065 "for power transition: code %d\n",
1066 dev_name(dev), error);
1070 dev->power.is_prepared = true;
1071 if (!list_empty(&dev->power.entry))
1072 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1075 mutex_unlock(&dpm_list_mtx);
1080 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1081 * @state: PM transition of the system being carried out.
1083 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1084 * callbacks for them.
1086 int dpm_suspend_start(pm_message_t state)
1090 error = dpm_prepare(state);
1092 error = dpm_suspend(state);
1095 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1097 void __suspend_report_result(const char *function, void *fn, int ret)
1100 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1102 EXPORT_SYMBOL_GPL(__suspend_report_result);
1105 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1106 * @dev: Device to wait for.
1107 * @subordinate: Device that needs to wait for @dev.
1109 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1111 dpm_wait(dev, subordinate->power.async_suspend);
1114 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);