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
;
54 static int async_error
;
57 * device_pm_init - Initialize the PM-related part of a device object.
58 * @dev: Device object being initialized.
60 void device_pm_init(struct device
*dev
)
62 dev
->power
.status
= DPM_ON
;
63 init_completion(&dev
->power
.completion
);
64 complete_all(&dev
->power
.completion
);
65 dev
->power
.wakeup
= NULL
;
66 spin_lock_init(&dev
->power
.lock
);
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",
94 kobject_name(&dev
->kobj
));
95 mutex_lock(&dpm_list_mtx
);
97 if (dev
->parent
->power
.status
>= DPM_SUSPENDING
)
98 dev_warn(dev
, "parent %s should not be sleeping\n",
99 dev_name(dev
->parent
));
100 } else if (transition_started
) {
102 * We refuse to register parentless devices while a PM
103 * transition is in progress in order to avoid leaving them
104 * unhandled down the road
106 dev_WARN(dev
, "Parentless device registered during a PM transaction\n");
109 list_add_tail(&dev
->power
.entry
, &dpm_list
);
110 mutex_unlock(&dpm_list_mtx
);
114 * device_pm_remove - Remove a device from the PM core's list of active devices.
115 * @dev: Device to be removed from the list.
117 void device_pm_remove(struct device
*dev
)
119 pr_debug("PM: Removing info for %s:%s\n",
120 dev
->bus
? dev
->bus
->name
: "No Bus",
121 kobject_name(&dev
->kobj
));
122 complete_all(&dev
->power
.completion
);
123 mutex_lock(&dpm_list_mtx
);
124 list_del_init(&dev
->power
.entry
);
125 mutex_unlock(&dpm_list_mtx
);
126 device_wakeup_disable(dev
);
127 pm_runtime_remove(dev
);
131 * device_pm_move_before - Move device in the PM core's list of active devices.
132 * @deva: Device to move in dpm_list.
133 * @devb: Device @deva should come before.
135 void device_pm_move_before(struct device
*deva
, struct device
*devb
)
137 pr_debug("PM: Moving %s:%s before %s:%s\n",
138 deva
->bus
? deva
->bus
->name
: "No Bus",
139 kobject_name(&deva
->kobj
),
140 devb
->bus
? devb
->bus
->name
: "No Bus",
141 kobject_name(&devb
->kobj
));
142 /* Delete deva from dpm_list and reinsert before devb. */
143 list_move_tail(&deva
->power
.entry
, &devb
->power
.entry
);
147 * device_pm_move_after - Move device in the PM core's list of active devices.
148 * @deva: Device to move in dpm_list.
149 * @devb: Device @deva should come after.
151 void device_pm_move_after(struct device
*deva
, struct device
*devb
)
153 pr_debug("PM: Moving %s:%s after %s:%s\n",
154 deva
->bus
? deva
->bus
->name
: "No Bus",
155 kobject_name(&deva
->kobj
),
156 devb
->bus
? devb
->bus
->name
: "No Bus",
157 kobject_name(&devb
->kobj
));
158 /* Delete deva from dpm_list and reinsert after devb. */
159 list_move(&deva
->power
.entry
, &devb
->power
.entry
);
163 * device_pm_move_last - Move device to end of the PM core's list of devices.
164 * @dev: Device to move in dpm_list.
166 void device_pm_move_last(struct device
*dev
)
168 pr_debug("PM: Moving %s:%s to end of list\n",
169 dev
->bus
? dev
->bus
->name
: "No Bus",
170 kobject_name(&dev
->kobj
));
171 list_move_tail(&dev
->power
.entry
, &dpm_list
);
174 static ktime_t
initcall_debug_start(struct device
*dev
)
176 ktime_t calltime
= ktime_set(0, 0);
178 if (initcall_debug
) {
179 pr_info("calling %s+ @ %i\n",
180 dev_name(dev
), task_pid_nr(current
));
181 calltime
= ktime_get();
187 static void initcall_debug_report(struct device
*dev
, ktime_t calltime
,
190 ktime_t delta
, rettime
;
192 if (initcall_debug
) {
193 rettime
= ktime_get();
194 delta
= ktime_sub(rettime
, calltime
);
195 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev
),
196 error
, (unsigned long long)ktime_to_ns(delta
) >> 10);
201 * dpm_wait - Wait for a PM operation to complete.
202 * @dev: Device to wait for.
203 * @async: If unset, wait only if the device's power.async_suspend flag is set.
205 static void dpm_wait(struct device
*dev
, bool async
)
210 if (async
|| (pm_async_enabled
&& dev
->power
.async_suspend
))
211 wait_for_completion(&dev
->power
.completion
);
214 static int dpm_wait_fn(struct device
*dev
, void *async_ptr
)
216 dpm_wait(dev
, *((bool *)async_ptr
));
220 static void dpm_wait_for_children(struct device
*dev
, bool async
)
222 device_for_each_child(dev
, &async
, dpm_wait_fn
);
226 * pm_op - Execute the PM operation appropriate for given PM event.
227 * @dev: Device to handle.
228 * @ops: PM operations to choose from.
229 * @state: PM transition of the system being carried out.
231 static int pm_op(struct device
*dev
,
232 const struct dev_pm_ops
*ops
,
238 calltime
= initcall_debug_start(dev
);
240 switch (state
.event
) {
241 #ifdef CONFIG_SUSPEND
242 case PM_EVENT_SUSPEND
:
244 error
= ops
->suspend(dev
);
245 suspend_report_result(ops
->suspend
, error
);
248 case PM_EVENT_RESUME
:
250 error
= ops
->resume(dev
);
251 suspend_report_result(ops
->resume
, error
);
254 #endif /* CONFIG_SUSPEND */
255 #ifdef CONFIG_HIBERNATION
256 case PM_EVENT_FREEZE
:
257 case PM_EVENT_QUIESCE
:
259 error
= ops
->freeze(dev
);
260 suspend_report_result(ops
->freeze
, error
);
263 case PM_EVENT_HIBERNATE
:
265 error
= ops
->poweroff(dev
);
266 suspend_report_result(ops
->poweroff
, error
);
270 case PM_EVENT_RECOVER
:
272 error
= ops
->thaw(dev
);
273 suspend_report_result(ops
->thaw
, error
);
276 case PM_EVENT_RESTORE
:
278 error
= ops
->restore(dev
);
279 suspend_report_result(ops
->restore
, error
);
282 #endif /* CONFIG_HIBERNATION */
287 initcall_debug_report(dev
, calltime
, error
);
293 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
294 * @dev: Device to handle.
295 * @ops: PM operations to choose from.
296 * @state: PM transition of the system being carried out.
298 * The driver of @dev will not receive interrupts while this function is being
301 static int pm_noirq_op(struct device
*dev
,
302 const struct dev_pm_ops
*ops
,
306 ktime_t calltime
, delta
, rettime
;
308 if (initcall_debug
) {
309 pr_info("calling %s+ @ %i, parent: %s\n",
310 dev_name(dev
), task_pid_nr(current
),
311 dev
->parent
? dev_name(dev
->parent
) : "none");
312 calltime
= ktime_get();
315 switch (state
.event
) {
316 #ifdef CONFIG_SUSPEND
317 case PM_EVENT_SUSPEND
:
318 if (ops
->suspend_noirq
) {
319 error
= ops
->suspend_noirq(dev
);
320 suspend_report_result(ops
->suspend_noirq
, error
);
323 case PM_EVENT_RESUME
:
324 if (ops
->resume_noirq
) {
325 error
= ops
->resume_noirq(dev
);
326 suspend_report_result(ops
->resume_noirq
, error
);
329 #endif /* CONFIG_SUSPEND */
330 #ifdef CONFIG_HIBERNATION
331 case PM_EVENT_FREEZE
:
332 case PM_EVENT_QUIESCE
:
333 if (ops
->freeze_noirq
) {
334 error
= ops
->freeze_noirq(dev
);
335 suspend_report_result(ops
->freeze_noirq
, error
);
338 case PM_EVENT_HIBERNATE
:
339 if (ops
->poweroff_noirq
) {
340 error
= ops
->poweroff_noirq(dev
);
341 suspend_report_result(ops
->poweroff_noirq
, error
);
345 case PM_EVENT_RECOVER
:
346 if (ops
->thaw_noirq
) {
347 error
= ops
->thaw_noirq(dev
);
348 suspend_report_result(ops
->thaw_noirq
, error
);
351 case PM_EVENT_RESTORE
:
352 if (ops
->restore_noirq
) {
353 error
= ops
->restore_noirq(dev
);
354 suspend_report_result(ops
->restore_noirq
, error
);
357 #endif /* CONFIG_HIBERNATION */
362 if (initcall_debug
) {
363 rettime
= ktime_get();
364 delta
= ktime_sub(rettime
, calltime
);
365 printk("initcall %s_i+ returned %d after %Ld usecs\n",
366 dev_name(dev
), error
,
367 (unsigned long long)ktime_to_ns(delta
) >> 10);
373 static char *pm_verb(int event
)
376 case PM_EVENT_SUSPEND
:
378 case PM_EVENT_RESUME
:
380 case PM_EVENT_FREEZE
:
382 case PM_EVENT_QUIESCE
:
384 case PM_EVENT_HIBERNATE
:
388 case PM_EVENT_RESTORE
:
390 case PM_EVENT_RECOVER
:
393 return "(unknown PM event)";
397 static void pm_dev_dbg(struct device
*dev
, pm_message_t state
, char *info
)
399 dev_dbg(dev
, "%s%s%s\n", info
, pm_verb(state
.event
),
400 ((state
.event
& PM_EVENT_SLEEP
) && device_may_wakeup(dev
)) ?
401 ", may wakeup" : "");
404 static void pm_dev_err(struct device
*dev
, pm_message_t state
, char *info
,
407 printk(KERN_ERR
"PM: Device %s failed to %s%s: error %d\n",
408 kobject_name(&dev
->kobj
), pm_verb(state
.event
), info
, error
);
411 static void dpm_show_time(ktime_t starttime
, pm_message_t state
, char *info
)
417 calltime
= ktime_get();
418 usecs64
= ktime_to_ns(ktime_sub(calltime
, starttime
));
419 do_div(usecs64
, NSEC_PER_USEC
);
423 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
424 info
?: "", info
? " " : "", pm_verb(state
.event
),
425 usecs
/ USEC_PER_MSEC
, usecs
% USEC_PER_MSEC
);
428 /*------------------------- Resume routines -------------------------*/
431 * device_resume_noirq - Execute an "early resume" callback for given device.
432 * @dev: Device to handle.
433 * @state: PM transition of the system being carried out.
435 * The driver of @dev will not receive interrupts while this function is being
438 static int device_resume_noirq(struct device
*dev
, pm_message_t state
)
445 if (dev
->bus
&& dev
->bus
->pm
) {
446 pm_dev_dbg(dev
, state
, "EARLY ");
447 error
= pm_noirq_op(dev
, dev
->bus
->pm
, state
);
452 if (dev
->type
&& dev
->type
->pm
) {
453 pm_dev_dbg(dev
, state
, "EARLY type ");
454 error
= pm_noirq_op(dev
, dev
->type
->pm
, state
);
459 if (dev
->class && dev
->class->pm
) {
460 pm_dev_dbg(dev
, state
, "EARLY class ");
461 error
= pm_noirq_op(dev
, dev
->class->pm
, state
);
470 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
471 * @state: PM transition of the system being carried out.
473 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
474 * enable device drivers to receive interrupts.
476 void dpm_resume_noirq(pm_message_t state
)
479 ktime_t starttime
= ktime_get();
481 mutex_lock(&dpm_list_mtx
);
482 transition_started
= false;
483 list_for_each_entry(dev
, &dpm_list
, power
.entry
)
484 if (dev
->power
.status
> DPM_OFF
) {
487 dev
->power
.status
= DPM_OFF
;
488 error
= device_resume_noirq(dev
, state
);
490 pm_dev_err(dev
, state
, " early", error
);
492 mutex_unlock(&dpm_list_mtx
);
493 dpm_show_time(starttime
, state
, "early");
494 resume_device_irqs();
496 EXPORT_SYMBOL_GPL(dpm_resume_noirq
);
499 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
500 * @dev: Device to resume.
501 * @cb: Resume callback to execute.
503 static int legacy_resume(struct device
*dev
, int (*cb
)(struct device
*dev
))
508 calltime
= initcall_debug_start(dev
);
511 suspend_report_result(cb
, error
);
513 initcall_debug_report(dev
, calltime
, error
);
519 * device_resume - Execute "resume" callbacks for given device.
520 * @dev: Device to handle.
521 * @state: PM transition of the system being carried out.
522 * @async: If true, the device is being resumed asynchronously.
524 static int device_resume(struct device
*dev
, pm_message_t state
, bool async
)
531 dpm_wait(dev
->parent
, async
);
534 dev
->power
.status
= DPM_RESUMING
;
538 pm_dev_dbg(dev
, state
, "");
539 error
= pm_op(dev
, dev
->bus
->pm
, state
);
540 } else if (dev
->bus
->resume
) {
541 pm_dev_dbg(dev
, state
, "legacy ");
542 error
= legacy_resume(dev
, dev
->bus
->resume
);
550 pm_dev_dbg(dev
, state
, "type ");
551 error
= pm_op(dev
, dev
->type
->pm
, state
);
558 if (dev
->class->pm
) {
559 pm_dev_dbg(dev
, state
, "class ");
560 error
= pm_op(dev
, dev
->class->pm
, state
);
561 } else if (dev
->class->resume
) {
562 pm_dev_dbg(dev
, state
, "legacy class ");
563 error
= legacy_resume(dev
, dev
->class->resume
);
568 complete_all(&dev
->power
.completion
);
574 static void async_resume(void *data
, async_cookie_t cookie
)
576 struct device
*dev
= (struct device
*)data
;
579 error
= device_resume(dev
, pm_transition
, true);
581 pm_dev_err(dev
, pm_transition
, " async", error
);
585 static bool is_async(struct device
*dev
)
587 return dev
->power
.async_suspend
&& pm_async_enabled
588 && !pm_trace_is_enabled();
592 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
593 * @state: PM transition of the system being carried out.
595 * Execute the appropriate "resume" callback for all devices whose status
596 * indicates that they are suspended.
598 static void dpm_resume(pm_message_t state
)
600 struct list_head list
;
602 ktime_t starttime
= ktime_get();
604 INIT_LIST_HEAD(&list
);
605 mutex_lock(&dpm_list_mtx
);
606 pm_transition
= state
;
609 list_for_each_entry(dev
, &dpm_list
, power
.entry
) {
610 if (dev
->power
.status
< DPM_OFF
)
613 INIT_COMPLETION(dev
->power
.completion
);
616 async_schedule(async_resume
, dev
);
620 while (!list_empty(&dpm_list
)) {
621 dev
= to_device(dpm_list
.next
);
623 if (dev
->power
.status
>= DPM_OFF
&& !is_async(dev
)) {
626 mutex_unlock(&dpm_list_mtx
);
628 error
= device_resume(dev
, state
, false);
630 mutex_lock(&dpm_list_mtx
);
632 pm_dev_err(dev
, state
, "", error
);
633 } else if (dev
->power
.status
== DPM_SUSPENDING
) {
634 /* Allow new children of the device to be registered */
635 dev
->power
.status
= DPM_RESUMING
;
637 if (!list_empty(&dev
->power
.entry
))
638 list_move_tail(&dev
->power
.entry
, &list
);
641 list_splice(&list
, &dpm_list
);
642 mutex_unlock(&dpm_list_mtx
);
643 async_synchronize_full();
644 dpm_show_time(starttime
, state
, NULL
);
648 * device_complete - Complete a PM transition for given device.
649 * @dev: Device to handle.
650 * @state: PM transition of the system being carried out.
652 static void device_complete(struct device
*dev
, pm_message_t state
)
656 if (dev
->class && dev
->class->pm
&& dev
->class->pm
->complete
) {
657 pm_dev_dbg(dev
, state
, "completing class ");
658 dev
->class->pm
->complete(dev
);
661 if (dev
->type
&& dev
->type
->pm
&& dev
->type
->pm
->complete
) {
662 pm_dev_dbg(dev
, state
, "completing type ");
663 dev
->type
->pm
->complete(dev
);
666 if (dev
->bus
&& dev
->bus
->pm
&& dev
->bus
->pm
->complete
) {
667 pm_dev_dbg(dev
, state
, "completing ");
668 dev
->bus
->pm
->complete(dev
);
675 * dpm_complete - Complete a PM transition for all non-sysdev devices.
676 * @state: PM transition of the system being carried out.
678 * Execute the ->complete() callbacks for all devices whose PM status is not
679 * DPM_ON (this allows new devices to be registered).
681 static void dpm_complete(pm_message_t state
)
683 struct list_head list
;
685 INIT_LIST_HEAD(&list
);
686 mutex_lock(&dpm_list_mtx
);
687 transition_started
= false;
688 while (!list_empty(&dpm_list
)) {
689 struct device
*dev
= to_device(dpm_list
.prev
);
692 if (dev
->power
.status
> DPM_ON
) {
693 dev
->power
.status
= DPM_ON
;
694 mutex_unlock(&dpm_list_mtx
);
696 device_complete(dev
, state
);
697 pm_runtime_put_sync(dev
);
699 mutex_lock(&dpm_list_mtx
);
701 if (!list_empty(&dev
->power
.entry
))
702 list_move(&dev
->power
.entry
, &list
);
705 list_splice(&list
, &dpm_list
);
706 mutex_unlock(&dpm_list_mtx
);
710 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
711 * @state: PM transition of the system being carried out.
713 * Execute "resume" callbacks for all devices and complete the PM transition of
716 void dpm_resume_end(pm_message_t state
)
722 EXPORT_SYMBOL_GPL(dpm_resume_end
);
725 /*------------------------- Suspend routines -------------------------*/
728 * resume_event - Return a "resume" message for given "suspend" sleep state.
729 * @sleep_state: PM message representing a sleep state.
731 * Return a PM message representing the resume event corresponding to given
734 static pm_message_t
resume_event(pm_message_t sleep_state
)
736 switch (sleep_state
.event
) {
737 case PM_EVENT_SUSPEND
:
739 case PM_EVENT_FREEZE
:
740 case PM_EVENT_QUIESCE
:
742 case PM_EVENT_HIBERNATE
:
749 * device_suspend_noirq - Execute a "late suspend" callback for given device.
750 * @dev: Device to handle.
751 * @state: PM transition of the system being carried out.
753 * The driver of @dev will not receive interrupts while this function is being
756 static int device_suspend_noirq(struct device
*dev
, pm_message_t state
)
760 if (dev
->class && dev
->class->pm
) {
761 pm_dev_dbg(dev
, state
, "LATE class ");
762 error
= pm_noirq_op(dev
, dev
->class->pm
, state
);
767 if (dev
->type
&& dev
->type
->pm
) {
768 pm_dev_dbg(dev
, state
, "LATE type ");
769 error
= pm_noirq_op(dev
, dev
->type
->pm
, state
);
774 if (dev
->bus
&& dev
->bus
->pm
) {
775 pm_dev_dbg(dev
, state
, "LATE ");
776 error
= pm_noirq_op(dev
, dev
->bus
->pm
, state
);
784 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
785 * @state: PM transition of the system being carried out.
787 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
788 * handlers for all non-sysdev devices.
790 int dpm_suspend_noirq(pm_message_t state
)
793 ktime_t starttime
= ktime_get();
796 suspend_device_irqs();
797 mutex_lock(&dpm_list_mtx
);
798 list_for_each_entry_reverse(dev
, &dpm_list
, power
.entry
) {
799 error
= device_suspend_noirq(dev
, state
);
801 pm_dev_err(dev
, state
, " late", error
);
804 dev
->power
.status
= DPM_OFF_IRQ
;
806 mutex_unlock(&dpm_list_mtx
);
808 dpm_resume_noirq(resume_event(state
));
810 dpm_show_time(starttime
, state
, "late");
813 EXPORT_SYMBOL_GPL(dpm_suspend_noirq
);
816 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
817 * @dev: Device to suspend.
818 * @state: PM transition of the system being carried out.
819 * @cb: Suspend callback to execute.
821 static int legacy_suspend(struct device
*dev
, pm_message_t state
,
822 int (*cb
)(struct device
*dev
, pm_message_t state
))
827 calltime
= initcall_debug_start(dev
);
829 error
= cb(dev
, state
);
830 suspend_report_result(cb
, error
);
832 initcall_debug_report(dev
, calltime
, error
);
838 * device_suspend - Execute "suspend" callbacks for given device.
839 * @dev: Device to handle.
840 * @state: PM transition of the system being carried out.
841 * @async: If true, the device is being suspended asynchronously.
843 static int __device_suspend(struct device
*dev
, pm_message_t state
, bool async
)
847 dpm_wait_for_children(dev
, async
);
854 if (dev
->class->pm
) {
855 pm_dev_dbg(dev
, state
, "class ");
856 error
= pm_op(dev
, dev
->class->pm
, state
);
857 } else if (dev
->class->suspend
) {
858 pm_dev_dbg(dev
, state
, "legacy class ");
859 error
= legacy_suspend(dev
, state
, dev
->class->suspend
);
867 pm_dev_dbg(dev
, state
, "type ");
868 error
= pm_op(dev
, dev
->type
->pm
, state
);
876 pm_dev_dbg(dev
, state
, "");
877 error
= pm_op(dev
, dev
->bus
->pm
, state
);
878 } else if (dev
->bus
->suspend
) {
879 pm_dev_dbg(dev
, state
, "legacy ");
880 error
= legacy_suspend(dev
, state
, dev
->bus
->suspend
);
885 dev
->power
.status
= DPM_OFF
;
889 complete_all(&dev
->power
.completion
);
897 static void async_suspend(void *data
, async_cookie_t cookie
)
899 struct device
*dev
= (struct device
*)data
;
902 error
= __device_suspend(dev
, pm_transition
, true);
904 pm_dev_err(dev
, pm_transition
, " async", error
);
909 static int device_suspend(struct device
*dev
)
911 INIT_COMPLETION(dev
->power
.completion
);
913 if (pm_async_enabled
&& dev
->power
.async_suspend
) {
915 async_schedule(async_suspend
, dev
);
919 return __device_suspend(dev
, pm_transition
, false);
923 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
924 * @state: PM transition of the system being carried out.
926 static int dpm_suspend(pm_message_t state
)
928 struct list_head list
;
929 ktime_t starttime
= ktime_get();
932 INIT_LIST_HEAD(&list
);
933 mutex_lock(&dpm_list_mtx
);
934 pm_transition
= state
;
936 while (!list_empty(&dpm_list
)) {
937 struct device
*dev
= to_device(dpm_list
.prev
);
940 mutex_unlock(&dpm_list_mtx
);
942 error
= device_suspend(dev
);
944 mutex_lock(&dpm_list_mtx
);
946 pm_dev_err(dev
, state
, "", error
);
950 if (!list_empty(&dev
->power
.entry
))
951 list_move(&dev
->power
.entry
, &list
);
956 list_splice(&list
, dpm_list
.prev
);
957 mutex_unlock(&dpm_list_mtx
);
958 async_synchronize_full();
962 dpm_show_time(starttime
, state
, NULL
);
967 * device_prepare - Prepare a device for system power transition.
968 * @dev: Device to handle.
969 * @state: PM transition of the system being carried out.
971 * Execute the ->prepare() callback(s) for given device. No new children of the
972 * device may be registered after this function has returned.
974 static int device_prepare(struct device
*dev
, pm_message_t state
)
980 if (dev
->bus
&& dev
->bus
->pm
&& dev
->bus
->pm
->prepare
) {
981 pm_dev_dbg(dev
, state
, "preparing ");
982 error
= dev
->bus
->pm
->prepare(dev
);
983 suspend_report_result(dev
->bus
->pm
->prepare
, error
);
988 if (dev
->type
&& dev
->type
->pm
&& dev
->type
->pm
->prepare
) {
989 pm_dev_dbg(dev
, state
, "preparing type ");
990 error
= dev
->type
->pm
->prepare(dev
);
991 suspend_report_result(dev
->type
->pm
->prepare
, error
);
996 if (dev
->class && dev
->class->pm
&& dev
->class->pm
->prepare
) {
997 pm_dev_dbg(dev
, state
, "preparing class ");
998 error
= dev
->class->pm
->prepare(dev
);
999 suspend_report_result(dev
->class->pm
->prepare
, error
);
1008 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1009 * @state: PM transition of the system being carried out.
1011 * Execute the ->prepare() callback(s) for all devices.
1013 static int dpm_prepare(pm_message_t state
)
1015 struct list_head list
;
1018 INIT_LIST_HEAD(&list
);
1019 mutex_lock(&dpm_list_mtx
);
1020 transition_started
= true;
1021 while (!list_empty(&dpm_list
)) {
1022 struct device
*dev
= to_device(dpm_list
.next
);
1025 dev
->power
.status
= DPM_PREPARING
;
1026 mutex_unlock(&dpm_list_mtx
);
1028 pm_runtime_get_noresume(dev
);
1029 if (pm_runtime_barrier(dev
) && device_may_wakeup(dev
)) {
1030 /* Wake-up requested during system sleep transition. */
1031 pm_runtime_put_sync(dev
);
1034 error
= device_prepare(dev
, state
);
1037 mutex_lock(&dpm_list_mtx
);
1039 dev
->power
.status
= DPM_ON
;
1040 if (error
== -EAGAIN
) {
1045 printk(KERN_ERR
"PM: Failed to prepare device %s "
1046 "for power transition: error %d\n",
1047 kobject_name(&dev
->kobj
), error
);
1051 dev
->power
.status
= DPM_SUSPENDING
;
1052 if (!list_empty(&dev
->power
.entry
))
1053 list_move_tail(&dev
->power
.entry
, &list
);
1056 list_splice(&list
, &dpm_list
);
1057 mutex_unlock(&dpm_list_mtx
);
1062 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1063 * @state: PM transition of the system being carried out.
1065 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1066 * callbacks for them.
1068 int dpm_suspend_start(pm_message_t state
)
1073 error
= dpm_prepare(state
);
1075 error
= dpm_suspend(state
);
1078 EXPORT_SYMBOL_GPL(dpm_suspend_start
);
1080 void __suspend_report_result(const char *function
, void *fn
, int ret
)
1083 printk(KERN_ERR
"%s(): %pF returns %d\n", function
, fn
, ret
);
1085 EXPORT_SYMBOL_GPL(__suspend_report_result
);
1088 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1089 * @dev: Device to wait for.
1090 * @subordinate: Device that needs to wait for @dev.
1092 int device_pm_wait_for_dev(struct device
*subordinate
, struct device
*dev
)
1094 dpm_wait(dev
, subordinate
->power
.async_suspend
);
1097 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev
);