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 intialize 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>
34 * The entries in the dpm_list list are in a depth first order, simply
35 * because children are guaranteed to be discovered after parents, and
36 * are inserted at the back of the list on discovery.
38 * Since device_pm_add() may be called with a device lock held,
39 * we must never try to acquire a device lock while holding
45 static DEFINE_MUTEX(dpm_list_mtx
);
46 static pm_message_t pm_transition
;
49 * Set once the preparation of devices for a PM transition has started, reset
50 * before starting to resume devices. Protected by dpm_list_mtx.
52 static bool transition_started
;
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
.status
= DPM_ON
;
61 init_completion(&dev
->power
.completion
);
66 * device_pm_lock - Lock the list of active devices used by the PM core.
68 void device_pm_lock(void)
70 mutex_lock(&dpm_list_mtx
);
74 * device_pm_unlock - Unlock the list of active devices used by the PM core.
76 void device_pm_unlock(void)
78 mutex_unlock(&dpm_list_mtx
);
82 * device_pm_add - Add a device to the PM core's list of active devices.
83 * @dev: Device to add to the list.
85 void device_pm_add(struct device
*dev
)
87 pr_debug("PM: Adding info for %s:%s\n",
88 dev
->bus
? dev
->bus
->name
: "No Bus",
89 kobject_name(&dev
->kobj
));
90 mutex_lock(&dpm_list_mtx
);
92 if (dev
->parent
->power
.status
>= DPM_SUSPENDING
)
93 dev_warn(dev
, "parent %s should not be sleeping\n",
94 dev_name(dev
->parent
));
95 } else if (transition_started
) {
97 * We refuse to register parentless devices while a PM
98 * transition is in progress in order to avoid leaving them
99 * unhandled down the road
101 dev_WARN(dev
, "Parentless device registered during a PM transaction\n");
104 list_add_tail(&dev
->power
.entry
, &dpm_list
);
105 mutex_unlock(&dpm_list_mtx
);
109 * device_pm_remove - Remove a device from the PM core's list of active devices.
110 * @dev: Device to be removed from the list.
112 void device_pm_remove(struct device
*dev
)
114 pr_debug("PM: Removing info for %s:%s\n",
115 dev
->bus
? dev
->bus
->name
: "No Bus",
116 kobject_name(&dev
->kobj
));
117 complete_all(&dev
->power
.completion
);
118 mutex_lock(&dpm_list_mtx
);
119 list_del_init(&dev
->power
.entry
);
120 mutex_unlock(&dpm_list_mtx
);
121 pm_runtime_remove(dev
);
125 * device_pm_move_before - Move device in the PM core's list of active devices.
126 * @deva: Device to move in dpm_list.
127 * @devb: Device @deva should come before.
129 void device_pm_move_before(struct device
*deva
, struct device
*devb
)
131 pr_debug("PM: Moving %s:%s before %s:%s\n",
132 deva
->bus
? deva
->bus
->name
: "No Bus",
133 kobject_name(&deva
->kobj
),
134 devb
->bus
? devb
->bus
->name
: "No Bus",
135 kobject_name(&devb
->kobj
));
136 /* Delete deva from dpm_list and reinsert before devb. */
137 list_move_tail(&deva
->power
.entry
, &devb
->power
.entry
);
141 * device_pm_move_after - Move device in the PM core's list of active devices.
142 * @deva: Device to move in dpm_list.
143 * @devb: Device @deva should come after.
145 void device_pm_move_after(struct device
*deva
, struct device
*devb
)
147 pr_debug("PM: Moving %s:%s after %s:%s\n",
148 deva
->bus
? deva
->bus
->name
: "No Bus",
149 kobject_name(&deva
->kobj
),
150 devb
->bus
? devb
->bus
->name
: "No Bus",
151 kobject_name(&devb
->kobj
));
152 /* Delete deva from dpm_list and reinsert after devb. */
153 list_move(&deva
->power
.entry
, &devb
->power
.entry
);
157 * device_pm_move_last - Move device to end of the PM core's list of devices.
158 * @dev: Device to move in dpm_list.
160 void device_pm_move_last(struct device
*dev
)
162 pr_debug("PM: Moving %s:%s to end of list\n",
163 dev
->bus
? dev
->bus
->name
: "No Bus",
164 kobject_name(&dev
->kobj
));
165 list_move_tail(&dev
->power
.entry
, &dpm_list
);
168 static ktime_t
initcall_debug_start(struct device
*dev
)
170 ktime_t calltime
= ktime_set(0, 0);
172 if (initcall_debug
) {
173 pr_info("calling %s+ @ %i\n",
174 dev_name(dev
), task_pid_nr(current
));
175 calltime
= ktime_get();
181 static void initcall_debug_report(struct device
*dev
, ktime_t calltime
,
184 ktime_t delta
, rettime
;
186 if (initcall_debug
) {
187 rettime
= ktime_get();
188 delta
= ktime_sub(rettime
, calltime
);
189 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev
),
190 error
, (unsigned long long)ktime_to_ns(delta
) >> 10);
195 * dpm_wait - Wait for a PM operation to complete.
196 * @dev: Device to wait for.
197 * @async: If unset, wait only if the device's power.async_suspend flag is set.
199 static void dpm_wait(struct device
*dev
, bool async
)
204 if (async
|| (pm_async_enabled
&& dev
->power
.async_suspend
))
205 wait_for_completion(&dev
->power
.completion
);
208 static int dpm_wait_fn(struct device
*dev
, void *async_ptr
)
210 dpm_wait(dev
, *((bool *)async_ptr
));
214 static void dpm_wait_for_children(struct device
*dev
, bool async
)
216 device_for_each_child(dev
, &async
, dpm_wait_fn
);
220 * pm_op - Execute the PM operation appropriate for given PM event.
221 * @dev: Device to handle.
222 * @ops: PM operations to choose from.
223 * @state: PM transition of the system being carried out.
225 static int pm_op(struct device
*dev
,
226 const struct dev_pm_ops
*ops
,
232 calltime
= initcall_debug_start(dev
);
234 switch (state
.event
) {
235 #ifdef CONFIG_SUSPEND
236 case PM_EVENT_SUSPEND
:
238 error
= ops
->suspend(dev
);
239 suspend_report_result(ops
->suspend
, error
);
242 case PM_EVENT_RESUME
:
244 error
= ops
->resume(dev
);
245 suspend_report_result(ops
->resume
, error
);
248 #endif /* CONFIG_SUSPEND */
249 #ifdef CONFIG_HIBERNATION
250 case PM_EVENT_FREEZE
:
251 case PM_EVENT_QUIESCE
:
253 error
= ops
->freeze(dev
);
254 suspend_report_result(ops
->freeze
, error
);
257 case PM_EVENT_HIBERNATE
:
259 error
= ops
->poweroff(dev
);
260 suspend_report_result(ops
->poweroff
, error
);
264 case PM_EVENT_RECOVER
:
266 error
= ops
->thaw(dev
);
267 suspend_report_result(ops
->thaw
, error
);
270 case PM_EVENT_RESTORE
:
272 error
= ops
->restore(dev
);
273 suspend_report_result(ops
->restore
, error
);
276 #endif /* CONFIG_HIBERNATION */
281 initcall_debug_report(dev
, calltime
, error
);
287 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
288 * @dev: Device to handle.
289 * @ops: PM operations to choose from.
290 * @state: PM transition of the system being carried out.
292 * The driver of @dev will not receive interrupts while this function is being
295 static int pm_noirq_op(struct device
*dev
,
296 const struct dev_pm_ops
*ops
,
300 ktime_t calltime
, delta
, rettime
;
302 if (initcall_debug
) {
303 pr_info("calling %s+ @ %i, parent: %s\n",
304 dev_name(dev
), task_pid_nr(current
),
305 dev
->parent
? dev_name(dev
->parent
) : "none");
306 calltime
= ktime_get();
309 switch (state
.event
) {
310 #ifdef CONFIG_SUSPEND
311 case PM_EVENT_SUSPEND
:
312 if (ops
->suspend_noirq
) {
313 error
= ops
->suspend_noirq(dev
);
314 suspend_report_result(ops
->suspend_noirq
, error
);
317 case PM_EVENT_RESUME
:
318 if (ops
->resume_noirq
) {
319 error
= ops
->resume_noirq(dev
);
320 suspend_report_result(ops
->resume_noirq
, error
);
323 #endif /* CONFIG_SUSPEND */
324 #ifdef CONFIG_HIBERNATION
325 case PM_EVENT_FREEZE
:
326 case PM_EVENT_QUIESCE
:
327 if (ops
->freeze_noirq
) {
328 error
= ops
->freeze_noirq(dev
);
329 suspend_report_result(ops
->freeze_noirq
, error
);
332 case PM_EVENT_HIBERNATE
:
333 if (ops
->poweroff_noirq
) {
334 error
= ops
->poweroff_noirq(dev
);
335 suspend_report_result(ops
->poweroff_noirq
, error
);
339 case PM_EVENT_RECOVER
:
340 if (ops
->thaw_noirq
) {
341 error
= ops
->thaw_noirq(dev
);
342 suspend_report_result(ops
->thaw_noirq
, error
);
345 case PM_EVENT_RESTORE
:
346 if (ops
->restore_noirq
) {
347 error
= ops
->restore_noirq(dev
);
348 suspend_report_result(ops
->restore_noirq
, error
);
351 #endif /* CONFIG_HIBERNATION */
356 if (initcall_debug
) {
357 rettime
= ktime_get();
358 delta
= ktime_sub(rettime
, calltime
);
359 printk("initcall %s_i+ returned %d after %Ld usecs\n",
360 dev_name(dev
), error
,
361 (unsigned long long)ktime_to_ns(delta
) >> 10);
367 static char *pm_verb(int event
)
370 case PM_EVENT_SUSPEND
:
372 case PM_EVENT_RESUME
:
374 case PM_EVENT_FREEZE
:
376 case PM_EVENT_QUIESCE
:
378 case PM_EVENT_HIBERNATE
:
382 case PM_EVENT_RESTORE
:
384 case PM_EVENT_RECOVER
:
387 return "(unknown PM event)";
391 static void pm_dev_dbg(struct device
*dev
, pm_message_t state
, char *info
)
393 dev_dbg(dev
, "%s%s%s\n", info
, pm_verb(state
.event
),
394 ((state
.event
& PM_EVENT_SLEEP
) && device_may_wakeup(dev
)) ?
395 ", may wakeup" : "");
398 static void pm_dev_err(struct device
*dev
, pm_message_t state
, char *info
,
401 printk(KERN_ERR
"PM: Device %s failed to %s%s: error %d\n",
402 kobject_name(&dev
->kobj
), pm_verb(state
.event
), info
, error
);
405 static void dpm_show_time(ktime_t starttime
, pm_message_t state
, char *info
)
411 calltime
= ktime_get();
412 usecs64
= ktime_to_ns(ktime_sub(calltime
, starttime
));
413 do_div(usecs64
, NSEC_PER_USEC
);
417 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
418 info
?: "", info
? " " : "", pm_verb(state
.event
),
419 usecs
/ USEC_PER_MSEC
, usecs
% USEC_PER_MSEC
);
422 /*------------------------- Resume routines -------------------------*/
425 * device_resume_noirq - Execute an "early resume" callback for given device.
426 * @dev: Device to handle.
427 * @state: PM transition of the system being carried out.
429 * The driver of @dev will not receive interrupts while this function is being
432 static int device_resume_noirq(struct device
*dev
, pm_message_t state
)
439 if (dev
->bus
&& dev
->bus
->pm
) {
440 pm_dev_dbg(dev
, state
, "EARLY ");
441 error
= pm_noirq_op(dev
, dev
->bus
->pm
, state
);
449 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
450 * @state: PM transition of the system being carried out.
452 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
453 * enable device drivers to receive interrupts.
455 void dpm_resume_noirq(pm_message_t state
)
458 ktime_t starttime
= ktime_get();
460 mutex_lock(&dpm_list_mtx
);
461 transition_started
= false;
462 list_for_each_entry(dev
, &dpm_list
, power
.entry
)
463 if (dev
->power
.status
> DPM_OFF
) {
466 dev
->power
.status
= DPM_OFF
;
467 error
= device_resume_noirq(dev
, state
);
469 pm_dev_err(dev
, state
, " early", error
);
471 mutex_unlock(&dpm_list_mtx
);
472 dpm_show_time(starttime
, state
, "early");
473 resume_device_irqs();
475 EXPORT_SYMBOL_GPL(dpm_resume_noirq
);
478 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
479 * @dev: Device to resume.
480 * @cb: Resume callback to execute.
482 static int legacy_resume(struct device
*dev
, int (*cb
)(struct device
*dev
))
487 calltime
= initcall_debug_start(dev
);
490 suspend_report_result(cb
, error
);
492 initcall_debug_report(dev
, calltime
, error
);
498 * device_resume - Execute "resume" callbacks for given device.
499 * @dev: Device to handle.
500 * @state: PM transition of the system being carried out.
501 * @async: If true, the device is being resumed asynchronously.
503 static int device_resume(struct device
*dev
, pm_message_t state
, bool async
)
510 dpm_wait(dev
->parent
, async
);
513 dev
->power
.status
= DPM_RESUMING
;
517 pm_dev_dbg(dev
, state
, "");
518 error
= pm_op(dev
, dev
->bus
->pm
, state
);
519 } else if (dev
->bus
->resume
) {
520 pm_dev_dbg(dev
, state
, "legacy ");
521 error
= legacy_resume(dev
, dev
->bus
->resume
);
529 pm_dev_dbg(dev
, state
, "type ");
530 error
= pm_op(dev
, dev
->type
->pm
, state
);
537 if (dev
->class->pm
) {
538 pm_dev_dbg(dev
, state
, "class ");
539 error
= pm_op(dev
, dev
->class->pm
, state
);
540 } else if (dev
->class->resume
) {
541 pm_dev_dbg(dev
, state
, "legacy class ");
542 error
= legacy_resume(dev
, dev
->class->resume
);
547 complete_all(&dev
->power
.completion
);
553 static void async_resume(void *data
, async_cookie_t cookie
)
555 struct device
*dev
= (struct device
*)data
;
558 error
= device_resume(dev
, pm_transition
, true);
560 pm_dev_err(dev
, pm_transition
, " async", error
);
564 static bool is_async(struct device
*dev
)
566 return dev
->power
.async_suspend
&& pm_async_enabled
567 && !pm_trace_is_enabled();
571 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
572 * @state: PM transition of the system being carried out.
574 * Execute the appropriate "resume" callback for all devices whose status
575 * indicates that they are suspended.
577 static void dpm_resume(pm_message_t state
)
579 struct list_head list
;
581 ktime_t starttime
= ktime_get();
583 INIT_LIST_HEAD(&list
);
584 mutex_lock(&dpm_list_mtx
);
585 pm_transition
= state
;
587 list_for_each_entry(dev
, &dpm_list
, power
.entry
) {
588 if (dev
->power
.status
< DPM_OFF
)
591 INIT_COMPLETION(dev
->power
.completion
);
594 async_schedule(async_resume
, dev
);
598 while (!list_empty(&dpm_list
)) {
599 dev
= to_device(dpm_list
.next
);
601 if (dev
->power
.status
>= DPM_OFF
&& !is_async(dev
)) {
604 mutex_unlock(&dpm_list_mtx
);
606 error
= device_resume(dev
, state
, false);
608 mutex_lock(&dpm_list_mtx
);
610 pm_dev_err(dev
, state
, "", error
);
611 } else if (dev
->power
.status
== DPM_SUSPENDING
) {
612 /* Allow new children of the device to be registered */
613 dev
->power
.status
= DPM_RESUMING
;
615 if (!list_empty(&dev
->power
.entry
))
616 list_move_tail(&dev
->power
.entry
, &list
);
619 list_splice(&list
, &dpm_list
);
620 mutex_unlock(&dpm_list_mtx
);
621 async_synchronize_full();
622 dpm_show_time(starttime
, state
, NULL
);
626 * device_complete - Complete a PM transition for given device.
627 * @dev: Device to handle.
628 * @state: PM transition of the system being carried out.
630 static void device_complete(struct device
*dev
, pm_message_t state
)
634 if (dev
->class && dev
->class->pm
&& dev
->class->pm
->complete
) {
635 pm_dev_dbg(dev
, state
, "completing class ");
636 dev
->class->pm
->complete(dev
);
639 if (dev
->type
&& dev
->type
->pm
&& dev
->type
->pm
->complete
) {
640 pm_dev_dbg(dev
, state
, "completing type ");
641 dev
->type
->pm
->complete(dev
);
644 if (dev
->bus
&& dev
->bus
->pm
&& dev
->bus
->pm
->complete
) {
645 pm_dev_dbg(dev
, state
, "completing ");
646 dev
->bus
->pm
->complete(dev
);
653 * dpm_complete - Complete a PM transition for all non-sysdev devices.
654 * @state: PM transition of the system being carried out.
656 * Execute the ->complete() callbacks for all devices whose PM status is not
657 * DPM_ON (this allows new devices to be registered).
659 static void dpm_complete(pm_message_t state
)
661 struct list_head list
;
663 INIT_LIST_HEAD(&list
);
664 mutex_lock(&dpm_list_mtx
);
665 transition_started
= false;
666 while (!list_empty(&dpm_list
)) {
667 struct device
*dev
= to_device(dpm_list
.prev
);
670 if (dev
->power
.status
> DPM_ON
) {
671 dev
->power
.status
= DPM_ON
;
672 mutex_unlock(&dpm_list_mtx
);
674 device_complete(dev
, state
);
675 pm_runtime_put_sync(dev
);
677 mutex_lock(&dpm_list_mtx
);
679 if (!list_empty(&dev
->power
.entry
))
680 list_move(&dev
->power
.entry
, &list
);
683 list_splice(&list
, &dpm_list
);
684 mutex_unlock(&dpm_list_mtx
);
688 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
689 * @state: PM transition of the system being carried out.
691 * Execute "resume" callbacks for all devices and complete the PM transition of
694 void dpm_resume_end(pm_message_t state
)
700 EXPORT_SYMBOL_GPL(dpm_resume_end
);
703 /*------------------------- Suspend routines -------------------------*/
706 * resume_event - Return a "resume" message for given "suspend" sleep state.
707 * @sleep_state: PM message representing a sleep state.
709 * Return a PM message representing the resume event corresponding to given
712 static pm_message_t
resume_event(pm_message_t sleep_state
)
714 switch (sleep_state
.event
) {
715 case PM_EVENT_SUSPEND
:
717 case PM_EVENT_FREEZE
:
718 case PM_EVENT_QUIESCE
:
720 case PM_EVENT_HIBERNATE
:
727 * device_suspend_noirq - Execute a "late suspend" callback for given device.
728 * @dev: Device to handle.
729 * @state: PM transition of the system being carried out.
731 * The driver of @dev will not receive interrupts while this function is being
734 static int device_suspend_noirq(struct device
*dev
, pm_message_t state
)
738 if (dev
->bus
&& dev
->bus
->pm
) {
739 pm_dev_dbg(dev
, state
, "LATE ");
740 error
= pm_noirq_op(dev
, dev
->bus
->pm
, state
);
746 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
747 * @state: PM transition of the system being carried out.
749 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
750 * handlers for all non-sysdev devices.
752 int dpm_suspend_noirq(pm_message_t state
)
755 ktime_t starttime
= ktime_get();
758 suspend_device_irqs();
759 mutex_lock(&dpm_list_mtx
);
760 list_for_each_entry_reverse(dev
, &dpm_list
, power
.entry
) {
761 error
= device_suspend_noirq(dev
, state
);
763 pm_dev_err(dev
, state
, " late", error
);
766 dev
->power
.status
= DPM_OFF_IRQ
;
768 mutex_unlock(&dpm_list_mtx
);
770 dpm_resume_noirq(resume_event(state
));
772 dpm_show_time(starttime
, state
, "late");
775 EXPORT_SYMBOL_GPL(dpm_suspend_noirq
);
778 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
779 * @dev: Device to suspend.
780 * @state: PM transition of the system being carried out.
781 * @cb: Suspend callback to execute.
783 static int legacy_suspend(struct device
*dev
, pm_message_t state
,
784 int (*cb
)(struct device
*dev
, pm_message_t state
))
789 calltime
= initcall_debug_start(dev
);
791 error
= cb(dev
, state
);
792 suspend_report_result(cb
, error
);
794 initcall_debug_report(dev
, calltime
, error
);
799 static int async_error
;
802 * device_suspend - Execute "suspend" callbacks for given device.
803 * @dev: Device to handle.
804 * @state: PM transition of the system being carried out.
805 * @async: If true, the device is being suspended asynchronously.
807 static int __device_suspend(struct device
*dev
, pm_message_t state
, bool async
)
811 dpm_wait_for_children(dev
, async
);
818 if (dev
->class->pm
) {
819 pm_dev_dbg(dev
, state
, "class ");
820 error
= pm_op(dev
, dev
->class->pm
, state
);
821 } else if (dev
->class->suspend
) {
822 pm_dev_dbg(dev
, state
, "legacy class ");
823 error
= legacy_suspend(dev
, state
, dev
->class->suspend
);
831 pm_dev_dbg(dev
, state
, "type ");
832 error
= pm_op(dev
, dev
->type
->pm
, state
);
840 pm_dev_dbg(dev
, state
, "");
841 error
= pm_op(dev
, dev
->bus
->pm
, state
);
842 } else if (dev
->bus
->suspend
) {
843 pm_dev_dbg(dev
, state
, "legacy ");
844 error
= legacy_suspend(dev
, state
, dev
->bus
->suspend
);
849 dev
->power
.status
= DPM_OFF
;
853 complete_all(&dev
->power
.completion
);
858 static void async_suspend(void *data
, async_cookie_t cookie
)
860 struct device
*dev
= (struct device
*)data
;
863 error
= __device_suspend(dev
, pm_transition
, true);
865 pm_dev_err(dev
, pm_transition
, " async", error
);
872 static int device_suspend(struct device
*dev
)
874 INIT_COMPLETION(dev
->power
.completion
);
876 if (pm_async_enabled
&& dev
->power
.async_suspend
) {
878 async_schedule(async_suspend
, dev
);
882 return __device_suspend(dev
, pm_transition
, false);
886 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
887 * @state: PM transition of the system being carried out.
889 static int dpm_suspend(pm_message_t state
)
891 struct list_head list
;
892 ktime_t starttime
= ktime_get();
895 INIT_LIST_HEAD(&list
);
896 mutex_lock(&dpm_list_mtx
);
897 pm_transition
= state
;
899 while (!list_empty(&dpm_list
)) {
900 struct device
*dev
= to_device(dpm_list
.prev
);
903 mutex_unlock(&dpm_list_mtx
);
905 error
= device_suspend(dev
);
907 mutex_lock(&dpm_list_mtx
);
909 pm_dev_err(dev
, state
, "", error
);
913 if (!list_empty(&dev
->power
.entry
))
914 list_move(&dev
->power
.entry
, &list
);
919 list_splice(&list
, dpm_list
.prev
);
920 mutex_unlock(&dpm_list_mtx
);
921 async_synchronize_full();
925 dpm_show_time(starttime
, state
, NULL
);
930 * device_prepare - Prepare a device for system power transition.
931 * @dev: Device to handle.
932 * @state: PM transition of the system being carried out.
934 * Execute the ->prepare() callback(s) for given device. No new children of the
935 * device may be registered after this function has returned.
937 static int device_prepare(struct device
*dev
, pm_message_t state
)
943 if (dev
->bus
&& dev
->bus
->pm
&& dev
->bus
->pm
->prepare
) {
944 pm_dev_dbg(dev
, state
, "preparing ");
945 error
= dev
->bus
->pm
->prepare(dev
);
946 suspend_report_result(dev
->bus
->pm
->prepare
, error
);
951 if (dev
->type
&& dev
->type
->pm
&& dev
->type
->pm
->prepare
) {
952 pm_dev_dbg(dev
, state
, "preparing type ");
953 error
= dev
->type
->pm
->prepare(dev
);
954 suspend_report_result(dev
->type
->pm
->prepare
, error
);
959 if (dev
->class && dev
->class->pm
&& dev
->class->pm
->prepare
) {
960 pm_dev_dbg(dev
, state
, "preparing class ");
961 error
= dev
->class->pm
->prepare(dev
);
962 suspend_report_result(dev
->class->pm
->prepare
, error
);
971 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
972 * @state: PM transition of the system being carried out.
974 * Execute the ->prepare() callback(s) for all devices.
976 static int dpm_prepare(pm_message_t state
)
978 struct list_head list
;
981 INIT_LIST_HEAD(&list
);
982 mutex_lock(&dpm_list_mtx
);
983 transition_started
= true;
984 while (!list_empty(&dpm_list
)) {
985 struct device
*dev
= to_device(dpm_list
.next
);
988 dev
->power
.status
= DPM_PREPARING
;
989 mutex_unlock(&dpm_list_mtx
);
991 pm_runtime_get_noresume(dev
);
992 if (pm_runtime_barrier(dev
) && device_may_wakeup(dev
)) {
993 /* Wake-up requested during system sleep transition. */
994 pm_runtime_put_sync(dev
);
997 error
= device_prepare(dev
, state
);
1000 mutex_lock(&dpm_list_mtx
);
1002 dev
->power
.status
= DPM_ON
;
1003 if (error
== -EAGAIN
) {
1008 printk(KERN_ERR
"PM: Failed to prepare device %s "
1009 "for power transition: error %d\n",
1010 kobject_name(&dev
->kobj
), error
);
1014 dev
->power
.status
= DPM_SUSPENDING
;
1015 if (!list_empty(&dev
->power
.entry
))
1016 list_move_tail(&dev
->power
.entry
, &list
);
1019 list_splice(&list
, &dpm_list
);
1020 mutex_unlock(&dpm_list_mtx
);
1025 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1026 * @state: PM transition of the system being carried out.
1028 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1029 * callbacks for them.
1031 int dpm_suspend_start(pm_message_t state
)
1036 error
= dpm_prepare(state
);
1038 error
= dpm_suspend(state
);
1041 EXPORT_SYMBOL_GPL(dpm_suspend_start
);
1043 void __suspend_report_result(const char *function
, void *fn
, int ret
)
1046 printk(KERN_ERR
"%s(): %pF returns %d\n", function
, fn
, ret
);
1048 EXPORT_SYMBOL_GPL(__suspend_report_result
);
1051 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1052 * @dev: Device to wait for.
1053 * @subordinate: Device that needs to wait for @dev.
1055 void device_pm_wait_for_dev(struct device
*subordinate
, struct device
*dev
)
1057 dpm_wait(dev
, subordinate
->power
.async_suspend
);
1059 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev
);