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/export.h>
23 #include <linux/mutex.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/pm-trace.h>
27 #include <linux/pm_wakeirq.h>
28 #include <linux/interrupt.h>
29 #include <linux/sched.h>
30 #include <linux/sched/debug.h>
31 #include <linux/async.h>
32 #include <linux/suspend.h>
33 #include <trace/events/power.h>
34 #include <linux/cpufreq.h>
35 #include <linux/cpuidle.h>
36 #include <linux/timer.h>
41 typedef int (*pm_callback_t
)(struct device
*);
44 * The entries in the dpm_list list are in a depth first order, simply
45 * because children are guaranteed to be discovered after parents, and
46 * are inserted at the back of the list on discovery.
48 * Since device_pm_add() may be called with a device lock held,
49 * we must never try to acquire a device lock while holding
54 static LIST_HEAD(dpm_prepared_list
);
55 static LIST_HEAD(dpm_suspended_list
);
56 static LIST_HEAD(dpm_late_early_list
);
57 static LIST_HEAD(dpm_noirq_list
);
59 struct suspend_stats suspend_stats
;
60 static DEFINE_MUTEX(dpm_list_mtx
);
61 static pm_message_t pm_transition
;
63 static int async_error
;
65 static char *pm_verb(int event
)
68 case PM_EVENT_SUSPEND
:
74 case PM_EVENT_QUIESCE
:
76 case PM_EVENT_HIBERNATE
:
80 case PM_EVENT_RESTORE
:
82 case PM_EVENT_RECOVER
:
85 return "(unknown PM event)";
90 * device_pm_sleep_init - Initialize system suspend-related device fields.
91 * @dev: Device object being initialized.
93 void device_pm_sleep_init(struct device
*dev
)
95 dev
->power
.is_prepared
= false;
96 dev
->power
.is_suspended
= false;
97 dev
->power
.is_noirq_suspended
= false;
98 dev
->power
.is_late_suspended
= false;
99 init_completion(&dev
->power
.completion
);
100 complete_all(&dev
->power
.completion
);
101 dev
->power
.wakeup
= NULL
;
102 INIT_LIST_HEAD(&dev
->power
.entry
);
106 * device_pm_lock - Lock the list of active devices used by the PM core.
108 void device_pm_lock(void)
110 mutex_lock(&dpm_list_mtx
);
114 * device_pm_unlock - Unlock the list of active devices used by the PM core.
116 void device_pm_unlock(void)
118 mutex_unlock(&dpm_list_mtx
);
122 * device_pm_add - Add a device to the PM core's list of active devices.
123 * @dev: Device to add to the list.
125 void device_pm_add(struct device
*dev
)
127 pr_debug("PM: Adding info for %s:%s\n",
128 dev
->bus
? dev
->bus
->name
: "No Bus", dev_name(dev
));
129 device_pm_check_callbacks(dev
);
130 mutex_lock(&dpm_list_mtx
);
131 if (dev
->parent
&& dev
->parent
->power
.is_prepared
)
132 dev_warn(dev
, "parent %s should not be sleeping\n",
133 dev_name(dev
->parent
));
134 list_add_tail(&dev
->power
.entry
, &dpm_list
);
135 dev
->power
.in_dpm_list
= true;
136 mutex_unlock(&dpm_list_mtx
);
140 * device_pm_remove - Remove a device from the PM core's list of active devices.
141 * @dev: Device to be removed from the list.
143 void device_pm_remove(struct device
*dev
)
145 pr_debug("PM: Removing info for %s:%s\n",
146 dev
->bus
? dev
->bus
->name
: "No Bus", dev_name(dev
));
147 complete_all(&dev
->power
.completion
);
148 mutex_lock(&dpm_list_mtx
);
149 list_del_init(&dev
->power
.entry
);
150 dev
->power
.in_dpm_list
= false;
151 mutex_unlock(&dpm_list_mtx
);
152 device_wakeup_disable(dev
);
153 pm_runtime_remove(dev
);
154 device_pm_check_callbacks(dev
);
158 * device_pm_move_before - Move device in the PM core's list of active devices.
159 * @deva: Device to move in dpm_list.
160 * @devb: Device @deva should come before.
162 void device_pm_move_before(struct device
*deva
, struct device
*devb
)
164 pr_debug("PM: Moving %s:%s before %s:%s\n",
165 deva
->bus
? deva
->bus
->name
: "No Bus", dev_name(deva
),
166 devb
->bus
? devb
->bus
->name
: "No Bus", dev_name(devb
));
167 /* Delete deva from dpm_list and reinsert before devb. */
168 list_move_tail(&deva
->power
.entry
, &devb
->power
.entry
);
172 * device_pm_move_after - Move device in the PM core's list of active devices.
173 * @deva: Device to move in dpm_list.
174 * @devb: Device @deva should come after.
176 void device_pm_move_after(struct device
*deva
, struct device
*devb
)
178 pr_debug("PM: Moving %s:%s after %s:%s\n",
179 deva
->bus
? deva
->bus
->name
: "No Bus", dev_name(deva
),
180 devb
->bus
? devb
->bus
->name
: "No Bus", dev_name(devb
));
181 /* Delete deva from dpm_list and reinsert after devb. */
182 list_move(&deva
->power
.entry
, &devb
->power
.entry
);
186 * device_pm_move_last - Move device to end of the PM core's list of devices.
187 * @dev: Device to move in dpm_list.
189 void device_pm_move_last(struct device
*dev
)
191 pr_debug("PM: Moving %s:%s to end of list\n",
192 dev
->bus
? dev
->bus
->name
: "No Bus", dev_name(dev
));
193 list_move_tail(&dev
->power
.entry
, &dpm_list
);
196 static ktime_t
initcall_debug_start(struct device
*dev
)
198 ktime_t calltime
= 0;
200 if (pm_print_times_enabled
) {
201 pr_info("calling %s+ @ %i, parent: %s\n",
202 dev_name(dev
), task_pid_nr(current
),
203 dev
->parent
? dev_name(dev
->parent
) : "none");
204 calltime
= ktime_get();
210 static void initcall_debug_report(struct device
*dev
, ktime_t calltime
,
211 int error
, pm_message_t state
, char *info
)
216 rettime
= ktime_get();
217 nsecs
= (s64
) ktime_to_ns(ktime_sub(rettime
, calltime
));
219 if (pm_print_times_enabled
) {
220 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev
),
221 error
, (unsigned long long)nsecs
>> 10);
226 * dpm_wait - Wait for a PM operation to complete.
227 * @dev: Device to wait for.
228 * @async: If unset, wait only if the device's power.async_suspend flag is set.
230 static void dpm_wait(struct device
*dev
, bool async
)
235 if (async
|| (pm_async_enabled
&& dev
->power
.async_suspend
))
236 wait_for_completion(&dev
->power
.completion
);
239 static int dpm_wait_fn(struct device
*dev
, void *async_ptr
)
241 dpm_wait(dev
, *((bool *)async_ptr
));
245 static void dpm_wait_for_children(struct device
*dev
, bool async
)
247 device_for_each_child(dev
, &async
, dpm_wait_fn
);
250 static void dpm_wait_for_suppliers(struct device
*dev
, bool async
)
252 struct device_link
*link
;
255 idx
= device_links_read_lock();
258 * If the supplier goes away right after we've checked the link to it,
259 * we'll wait for its completion to change the state, but that's fine,
260 * because the only things that will block as a result are the SRCU
261 * callbacks freeing the link objects for the links in the list we're
264 list_for_each_entry_rcu(link
, &dev
->links
.suppliers
, c_node
)
265 if (READ_ONCE(link
->status
) != DL_STATE_DORMANT
)
266 dpm_wait(link
->supplier
, async
);
268 device_links_read_unlock(idx
);
271 static void dpm_wait_for_superior(struct device
*dev
, bool async
)
273 dpm_wait(dev
->parent
, async
);
274 dpm_wait_for_suppliers(dev
, async
);
277 static void dpm_wait_for_consumers(struct device
*dev
, bool async
)
279 struct device_link
*link
;
282 idx
= device_links_read_lock();
285 * The status of a device link can only be changed from "dormant" by a
286 * probe, but that cannot happen during system suspend/resume. In
287 * theory it can change to "dormant" at that time, but then it is
288 * reasonable to wait for the target device anyway (eg. if it goes
289 * away, it's better to wait for it to go away completely and then
290 * continue instead of trying to continue in parallel with its
293 list_for_each_entry_rcu(link
, &dev
->links
.consumers
, s_node
)
294 if (READ_ONCE(link
->status
) != DL_STATE_DORMANT
)
295 dpm_wait(link
->consumer
, async
);
297 device_links_read_unlock(idx
);
300 static void dpm_wait_for_subordinate(struct device
*dev
, bool async
)
302 dpm_wait_for_children(dev
, async
);
303 dpm_wait_for_consumers(dev
, async
);
307 * pm_op - Return the PM operation appropriate for given PM event.
308 * @ops: PM operations to choose from.
309 * @state: PM transition of the system being carried out.
311 static pm_callback_t
pm_op(const struct dev_pm_ops
*ops
, pm_message_t state
)
313 switch (state
.event
) {
314 #ifdef CONFIG_SUSPEND
315 case PM_EVENT_SUSPEND
:
317 case PM_EVENT_RESUME
:
319 #endif /* CONFIG_SUSPEND */
320 #ifdef CONFIG_HIBERNATE_CALLBACKS
321 case PM_EVENT_FREEZE
:
322 case PM_EVENT_QUIESCE
:
324 case PM_EVENT_HIBERNATE
:
325 return ops
->poweroff
;
327 case PM_EVENT_RECOVER
:
330 case PM_EVENT_RESTORE
:
332 #endif /* CONFIG_HIBERNATE_CALLBACKS */
339 * pm_late_early_op - Return the PM operation appropriate for given PM event.
340 * @ops: PM operations to choose from.
341 * @state: PM transition of the system being carried out.
343 * Runtime PM is disabled for @dev while this function is being executed.
345 static pm_callback_t
pm_late_early_op(const struct dev_pm_ops
*ops
,
348 switch (state
.event
) {
349 #ifdef CONFIG_SUSPEND
350 case PM_EVENT_SUSPEND
:
351 return ops
->suspend_late
;
352 case PM_EVENT_RESUME
:
353 return ops
->resume_early
;
354 #endif /* CONFIG_SUSPEND */
355 #ifdef CONFIG_HIBERNATE_CALLBACKS
356 case PM_EVENT_FREEZE
:
357 case PM_EVENT_QUIESCE
:
358 return ops
->freeze_late
;
359 case PM_EVENT_HIBERNATE
:
360 return ops
->poweroff_late
;
362 case PM_EVENT_RECOVER
:
363 return ops
->thaw_early
;
364 case PM_EVENT_RESTORE
:
365 return ops
->restore_early
;
366 #endif /* CONFIG_HIBERNATE_CALLBACKS */
373 * pm_noirq_op - Return the PM operation appropriate for given PM event.
374 * @ops: PM operations to choose from.
375 * @state: PM transition of the system being carried out.
377 * The driver of @dev will not receive interrupts while this function is being
380 static pm_callback_t
pm_noirq_op(const struct dev_pm_ops
*ops
, pm_message_t state
)
382 switch (state
.event
) {
383 #ifdef CONFIG_SUSPEND
384 case PM_EVENT_SUSPEND
:
385 return ops
->suspend_noirq
;
386 case PM_EVENT_RESUME
:
387 return ops
->resume_noirq
;
388 #endif /* CONFIG_SUSPEND */
389 #ifdef CONFIG_HIBERNATE_CALLBACKS
390 case PM_EVENT_FREEZE
:
391 case PM_EVENT_QUIESCE
:
392 return ops
->freeze_noirq
;
393 case PM_EVENT_HIBERNATE
:
394 return ops
->poweroff_noirq
;
396 case PM_EVENT_RECOVER
:
397 return ops
->thaw_noirq
;
398 case PM_EVENT_RESTORE
:
399 return ops
->restore_noirq
;
400 #endif /* CONFIG_HIBERNATE_CALLBACKS */
406 static void pm_dev_dbg(struct device
*dev
, pm_message_t state
, char *info
)
408 dev_dbg(dev
, "%s%s%s\n", info
, pm_verb(state
.event
),
409 ((state
.event
& PM_EVENT_SLEEP
) && device_may_wakeup(dev
)) ?
410 ", may wakeup" : "");
413 static void pm_dev_err(struct device
*dev
, pm_message_t state
, char *info
,
416 printk(KERN_ERR
"PM: Device %s failed to %s%s: error %d\n",
417 dev_name(dev
), pm_verb(state
.event
), info
, error
);
420 static void dpm_show_time(ktime_t starttime
, pm_message_t state
, char *info
)
426 calltime
= ktime_get();
427 usecs64
= ktime_to_ns(ktime_sub(calltime
, starttime
));
428 do_div(usecs64
, NSEC_PER_USEC
);
432 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
433 info
?: "", info
? " " : "", pm_verb(state
.event
),
434 usecs
/ USEC_PER_MSEC
, usecs
% USEC_PER_MSEC
);
437 static int dpm_run_callback(pm_callback_t cb
, struct device
*dev
,
438 pm_message_t state
, char *info
)
446 calltime
= initcall_debug_start(dev
);
448 pm_dev_dbg(dev
, state
, info
);
449 trace_device_pm_callback_start(dev
, info
, state
.event
);
451 trace_device_pm_callback_end(dev
, error
);
452 suspend_report_result(cb
, error
);
454 initcall_debug_report(dev
, calltime
, error
, state
, info
);
459 #ifdef CONFIG_DPM_WATCHDOG
460 struct dpm_watchdog
{
462 struct task_struct
*tsk
;
463 struct timer_list timer
;
466 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
467 struct dpm_watchdog wd
470 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
471 * @data: Watchdog object address.
473 * Called when a driver has timed out suspending or resuming.
474 * There's not much we can do here to recover so panic() to
475 * capture a crash-dump in pstore.
477 static void dpm_watchdog_handler(unsigned long data
)
479 struct dpm_watchdog
*wd
= (void *)data
;
481 dev_emerg(wd
->dev
, "**** DPM device timeout ****\n");
482 show_stack(wd
->tsk
, NULL
);
483 panic("%s %s: unrecoverable failure\n",
484 dev_driver_string(wd
->dev
), dev_name(wd
->dev
));
488 * dpm_watchdog_set - Enable pm watchdog for given device.
489 * @wd: Watchdog. Must be allocated on the stack.
490 * @dev: Device to handle.
492 static void dpm_watchdog_set(struct dpm_watchdog
*wd
, struct device
*dev
)
494 struct timer_list
*timer
= &wd
->timer
;
499 init_timer_on_stack(timer
);
500 /* use same timeout value for both suspend and resume */
501 timer
->expires
= jiffies
+ HZ
* CONFIG_DPM_WATCHDOG_TIMEOUT
;
502 timer
->function
= dpm_watchdog_handler
;
503 timer
->data
= (unsigned long)wd
;
508 * dpm_watchdog_clear - Disable suspend/resume watchdog.
509 * @wd: Watchdog to disable.
511 static void dpm_watchdog_clear(struct dpm_watchdog
*wd
)
513 struct timer_list
*timer
= &wd
->timer
;
515 del_timer_sync(timer
);
516 destroy_timer_on_stack(timer
);
519 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
520 #define dpm_watchdog_set(x, y)
521 #define dpm_watchdog_clear(x)
524 /*------------------------- Resume routines -------------------------*/
527 * device_resume_noirq - Execute an "early resume" callback for given device.
528 * @dev: Device to handle.
529 * @state: PM transition of the system being carried out.
530 * @async: If true, the device is being resumed asynchronously.
532 * The driver of @dev will not receive interrupts while this function is being
535 static int device_resume_noirq(struct device
*dev
, pm_message_t state
, bool async
)
537 pm_callback_t callback
= NULL
;
544 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
547 if (!dev
->power
.is_noirq_suspended
)
550 dpm_wait_for_superior(dev
, async
);
552 if (dev
->pm_domain
) {
553 info
= "noirq power domain ";
554 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
555 } else if (dev
->type
&& dev
->type
->pm
) {
556 info
= "noirq type ";
557 callback
= pm_noirq_op(dev
->type
->pm
, state
);
558 } else if (dev
->class && dev
->class->pm
) {
559 info
= "noirq class ";
560 callback
= pm_noirq_op(dev
->class->pm
, state
);
561 } else if (dev
->bus
&& dev
->bus
->pm
) {
563 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
566 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
567 info
= "noirq driver ";
568 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
571 error
= dpm_run_callback(callback
, dev
, state
, info
);
572 dev
->power
.is_noirq_suspended
= false;
575 complete_all(&dev
->power
.completion
);
580 static bool is_async(struct device
*dev
)
582 return dev
->power
.async_suspend
&& pm_async_enabled
583 && !pm_trace_is_enabled();
586 static void async_resume_noirq(void *data
, async_cookie_t cookie
)
588 struct device
*dev
= (struct device
*)data
;
591 error
= device_resume_noirq(dev
, pm_transition
, true);
593 pm_dev_err(dev
, pm_transition
, " async", error
);
599 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
600 * @state: PM transition of the system being carried out.
602 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
603 * enable device drivers to receive interrupts.
605 void dpm_resume_noirq(pm_message_t state
)
608 ktime_t starttime
= ktime_get();
610 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, true);
611 mutex_lock(&dpm_list_mtx
);
612 pm_transition
= state
;
615 * Advanced the async threads upfront,
616 * in case the starting of async threads is
617 * delayed by non-async resuming devices.
619 list_for_each_entry(dev
, &dpm_noirq_list
, power
.entry
) {
620 reinit_completion(&dev
->power
.completion
);
623 async_schedule(async_resume_noirq
, dev
);
627 while (!list_empty(&dpm_noirq_list
)) {
628 dev
= to_device(dpm_noirq_list
.next
);
630 list_move_tail(&dev
->power
.entry
, &dpm_late_early_list
);
631 mutex_unlock(&dpm_list_mtx
);
633 if (!is_async(dev
)) {
636 error
= device_resume_noirq(dev
, state
, false);
638 suspend_stats
.failed_resume_noirq
++;
639 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ
);
640 dpm_save_failed_dev(dev_name(dev
));
641 pm_dev_err(dev
, state
, " noirq", error
);
645 mutex_lock(&dpm_list_mtx
);
648 mutex_unlock(&dpm_list_mtx
);
649 async_synchronize_full();
650 dpm_show_time(starttime
, state
, "noirq");
651 resume_device_irqs();
652 device_wakeup_disarm_wake_irqs();
654 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, false);
658 * device_resume_early - Execute an "early resume" callback for given device.
659 * @dev: Device to handle.
660 * @state: PM transition of the system being carried out.
661 * @async: If true, the device is being resumed asynchronously.
663 * Runtime PM is disabled for @dev while this function is being executed.
665 static int device_resume_early(struct device
*dev
, pm_message_t state
, bool async
)
667 pm_callback_t callback
= NULL
;
674 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
677 if (!dev
->power
.is_late_suspended
)
680 dpm_wait_for_superior(dev
, async
);
682 if (dev
->pm_domain
) {
683 info
= "early power domain ";
684 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
685 } else if (dev
->type
&& dev
->type
->pm
) {
686 info
= "early type ";
687 callback
= pm_late_early_op(dev
->type
->pm
, state
);
688 } else if (dev
->class && dev
->class->pm
) {
689 info
= "early class ";
690 callback
= pm_late_early_op(dev
->class->pm
, state
);
691 } else if (dev
->bus
&& dev
->bus
->pm
) {
693 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
696 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
697 info
= "early driver ";
698 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
701 error
= dpm_run_callback(callback
, dev
, state
, info
);
702 dev
->power
.is_late_suspended
= false;
707 pm_runtime_enable(dev
);
708 complete_all(&dev
->power
.completion
);
712 static void async_resume_early(void *data
, async_cookie_t cookie
)
714 struct device
*dev
= (struct device
*)data
;
717 error
= device_resume_early(dev
, pm_transition
, true);
719 pm_dev_err(dev
, pm_transition
, " async", error
);
725 * dpm_resume_early - Execute "early resume" callbacks for all devices.
726 * @state: PM transition of the system being carried out.
728 void dpm_resume_early(pm_message_t state
)
731 ktime_t starttime
= ktime_get();
733 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, true);
734 mutex_lock(&dpm_list_mtx
);
735 pm_transition
= state
;
738 * Advanced the async threads upfront,
739 * in case the starting of async threads is
740 * delayed by non-async resuming devices.
742 list_for_each_entry(dev
, &dpm_late_early_list
, power
.entry
) {
743 reinit_completion(&dev
->power
.completion
);
746 async_schedule(async_resume_early
, dev
);
750 while (!list_empty(&dpm_late_early_list
)) {
751 dev
= to_device(dpm_late_early_list
.next
);
753 list_move_tail(&dev
->power
.entry
, &dpm_suspended_list
);
754 mutex_unlock(&dpm_list_mtx
);
756 if (!is_async(dev
)) {
759 error
= device_resume_early(dev
, state
, false);
761 suspend_stats
.failed_resume_early
++;
762 dpm_save_failed_step(SUSPEND_RESUME_EARLY
);
763 dpm_save_failed_dev(dev_name(dev
));
764 pm_dev_err(dev
, state
, " early", error
);
767 mutex_lock(&dpm_list_mtx
);
770 mutex_unlock(&dpm_list_mtx
);
771 async_synchronize_full();
772 dpm_show_time(starttime
, state
, "early");
773 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, false);
777 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
778 * @state: PM transition of the system being carried out.
780 void dpm_resume_start(pm_message_t state
)
782 dpm_resume_noirq(state
);
783 dpm_resume_early(state
);
785 EXPORT_SYMBOL_GPL(dpm_resume_start
);
788 * device_resume - Execute "resume" callbacks for given device.
789 * @dev: Device to handle.
790 * @state: PM transition of the system being carried out.
791 * @async: If true, the device is being resumed asynchronously.
793 static int device_resume(struct device
*dev
, pm_message_t state
, bool async
)
795 pm_callback_t callback
= NULL
;
798 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
803 if (dev
->power
.syscore
)
806 if (dev
->power
.direct_complete
) {
807 /* Match the pm_runtime_disable() in __device_suspend(). */
808 pm_runtime_enable(dev
);
812 dpm_wait_for_superior(dev
, async
);
813 dpm_watchdog_set(&wd
, dev
);
817 * This is a fib. But we'll allow new children to be added below
818 * a resumed device, even if the device hasn't been completed yet.
820 dev
->power
.is_prepared
= false;
822 if (!dev
->power
.is_suspended
)
825 if (dev
->pm_domain
) {
826 info
= "power domain ";
827 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
831 if (dev
->type
&& dev
->type
->pm
) {
833 callback
= pm_op(dev
->type
->pm
, state
);
838 if (dev
->class->pm
) {
840 callback
= pm_op(dev
->class->pm
, state
);
842 } else if (dev
->class->resume
) {
843 info
= "legacy class ";
844 callback
= dev
->class->resume
;
852 callback
= pm_op(dev
->bus
->pm
, state
);
853 } else if (dev
->bus
->resume
) {
854 info
= "legacy bus ";
855 callback
= dev
->bus
->resume
;
861 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
863 callback
= pm_op(dev
->driver
->pm
, state
);
867 error
= dpm_run_callback(callback
, dev
, state
, info
);
868 dev
->power
.is_suspended
= false;
872 dpm_watchdog_clear(&wd
);
875 complete_all(&dev
->power
.completion
);
882 static void async_resume(void *data
, async_cookie_t cookie
)
884 struct device
*dev
= (struct device
*)data
;
887 error
= device_resume(dev
, pm_transition
, true);
889 pm_dev_err(dev
, pm_transition
, " async", error
);
894 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
895 * @state: PM transition of the system being carried out.
897 * Execute the appropriate "resume" callback for all devices whose status
898 * indicates that they are suspended.
900 void dpm_resume(pm_message_t state
)
903 ktime_t starttime
= ktime_get();
905 trace_suspend_resume(TPS("dpm_resume"), state
.event
, true);
908 mutex_lock(&dpm_list_mtx
);
909 pm_transition
= state
;
912 list_for_each_entry(dev
, &dpm_suspended_list
, power
.entry
) {
913 reinit_completion(&dev
->power
.completion
);
916 async_schedule(async_resume
, dev
);
920 while (!list_empty(&dpm_suspended_list
)) {
921 dev
= to_device(dpm_suspended_list
.next
);
923 if (!is_async(dev
)) {
926 mutex_unlock(&dpm_list_mtx
);
928 error
= device_resume(dev
, state
, false);
930 suspend_stats
.failed_resume
++;
931 dpm_save_failed_step(SUSPEND_RESUME
);
932 dpm_save_failed_dev(dev_name(dev
));
933 pm_dev_err(dev
, state
, "", error
);
936 mutex_lock(&dpm_list_mtx
);
938 if (!list_empty(&dev
->power
.entry
))
939 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
942 mutex_unlock(&dpm_list_mtx
);
943 async_synchronize_full();
944 dpm_show_time(starttime
, state
, NULL
);
947 trace_suspend_resume(TPS("dpm_resume"), state
.event
, false);
951 * device_complete - Complete a PM transition for given device.
952 * @dev: Device to handle.
953 * @state: PM transition of the system being carried out.
955 static void device_complete(struct device
*dev
, pm_message_t state
)
957 void (*callback
)(struct device
*) = NULL
;
960 if (dev
->power
.syscore
)
965 if (dev
->pm_domain
) {
966 info
= "completing power domain ";
967 callback
= dev
->pm_domain
->ops
.complete
;
968 } else if (dev
->type
&& dev
->type
->pm
) {
969 info
= "completing type ";
970 callback
= dev
->type
->pm
->complete
;
971 } else if (dev
->class && dev
->class->pm
) {
972 info
= "completing class ";
973 callback
= dev
->class->pm
->complete
;
974 } else if (dev
->bus
&& dev
->bus
->pm
) {
975 info
= "completing bus ";
976 callback
= dev
->bus
->pm
->complete
;
979 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
980 info
= "completing driver ";
981 callback
= dev
->driver
->pm
->complete
;
985 pm_dev_dbg(dev
, state
, info
);
995 * dpm_complete - Complete a PM transition for all non-sysdev devices.
996 * @state: PM transition of the system being carried out.
998 * Execute the ->complete() callbacks for all devices whose PM status is not
999 * DPM_ON (this allows new devices to be registered).
1001 void dpm_complete(pm_message_t state
)
1003 struct list_head list
;
1005 trace_suspend_resume(TPS("dpm_complete"), state
.event
, true);
1008 INIT_LIST_HEAD(&list
);
1009 mutex_lock(&dpm_list_mtx
);
1010 while (!list_empty(&dpm_prepared_list
)) {
1011 struct device
*dev
= to_device(dpm_prepared_list
.prev
);
1014 dev
->power
.is_prepared
= false;
1015 list_move(&dev
->power
.entry
, &list
);
1016 mutex_unlock(&dpm_list_mtx
);
1018 trace_device_pm_callback_start(dev
, "", state
.event
);
1019 device_complete(dev
, state
);
1020 trace_device_pm_callback_end(dev
, 0);
1022 mutex_lock(&dpm_list_mtx
);
1025 list_splice(&list
, &dpm_list
);
1026 mutex_unlock(&dpm_list_mtx
);
1028 /* Allow device probing and trigger re-probing of deferred devices */
1029 device_unblock_probing();
1030 trace_suspend_resume(TPS("dpm_complete"), state
.event
, false);
1034 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1035 * @state: PM transition of the system being carried out.
1037 * Execute "resume" callbacks for all devices and complete the PM transition of
1040 void dpm_resume_end(pm_message_t state
)
1043 dpm_complete(state
);
1045 EXPORT_SYMBOL_GPL(dpm_resume_end
);
1048 /*------------------------- Suspend routines -------------------------*/
1051 * resume_event - Return a "resume" message for given "suspend" sleep state.
1052 * @sleep_state: PM message representing a sleep state.
1054 * Return a PM message representing the resume event corresponding to given
1057 static pm_message_t
resume_event(pm_message_t sleep_state
)
1059 switch (sleep_state
.event
) {
1060 case PM_EVENT_SUSPEND
:
1062 case PM_EVENT_FREEZE
:
1063 case PM_EVENT_QUIESCE
:
1064 return PMSG_RECOVER
;
1065 case PM_EVENT_HIBERNATE
:
1066 return PMSG_RESTORE
;
1072 * device_suspend_noirq - Execute a "late suspend" callback for given device.
1073 * @dev: Device to handle.
1074 * @state: PM transition of the system being carried out.
1075 * @async: If true, the device is being suspended asynchronously.
1077 * The driver of @dev will not receive interrupts while this function is being
1080 static int __device_suspend_noirq(struct device
*dev
, pm_message_t state
, bool async
)
1082 pm_callback_t callback
= NULL
;
1089 dpm_wait_for_subordinate(dev
, async
);
1094 if (pm_wakeup_pending()) {
1095 async_error
= -EBUSY
;
1099 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1102 if (dev
->pm_domain
) {
1103 info
= "noirq power domain ";
1104 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
1105 } else if (dev
->type
&& dev
->type
->pm
) {
1106 info
= "noirq type ";
1107 callback
= pm_noirq_op(dev
->type
->pm
, state
);
1108 } else if (dev
->class && dev
->class->pm
) {
1109 info
= "noirq class ";
1110 callback
= pm_noirq_op(dev
->class->pm
, state
);
1111 } else if (dev
->bus
&& dev
->bus
->pm
) {
1112 info
= "noirq bus ";
1113 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
1116 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1117 info
= "noirq driver ";
1118 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
1121 error
= dpm_run_callback(callback
, dev
, state
, info
);
1123 dev
->power
.is_noirq_suspended
= true;
1125 async_error
= error
;
1128 complete_all(&dev
->power
.completion
);
1129 TRACE_SUSPEND(error
);
1133 static void async_suspend_noirq(void *data
, async_cookie_t cookie
)
1135 struct device
*dev
= (struct device
*)data
;
1138 error
= __device_suspend_noirq(dev
, pm_transition
, true);
1140 dpm_save_failed_dev(dev_name(dev
));
1141 pm_dev_err(dev
, pm_transition
, " async", error
);
1147 static int device_suspend_noirq(struct device
*dev
)
1149 reinit_completion(&dev
->power
.completion
);
1151 if (is_async(dev
)) {
1153 async_schedule(async_suspend_noirq
, dev
);
1156 return __device_suspend_noirq(dev
, pm_transition
, false);
1160 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1161 * @state: PM transition of the system being carried out.
1163 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
1164 * handlers for all non-sysdev devices.
1166 int dpm_suspend_noirq(pm_message_t state
)
1168 ktime_t starttime
= ktime_get();
1171 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, true);
1173 device_wakeup_arm_wake_irqs();
1174 suspend_device_irqs();
1175 mutex_lock(&dpm_list_mtx
);
1176 pm_transition
= state
;
1179 while (!list_empty(&dpm_late_early_list
)) {
1180 struct device
*dev
= to_device(dpm_late_early_list
.prev
);
1183 mutex_unlock(&dpm_list_mtx
);
1185 error
= device_suspend_noirq(dev
);
1187 mutex_lock(&dpm_list_mtx
);
1189 pm_dev_err(dev
, state
, " noirq", error
);
1190 dpm_save_failed_dev(dev_name(dev
));
1194 if (!list_empty(&dev
->power
.entry
))
1195 list_move(&dev
->power
.entry
, &dpm_noirq_list
);
1201 mutex_unlock(&dpm_list_mtx
);
1202 async_synchronize_full();
1204 error
= async_error
;
1207 suspend_stats
.failed_suspend_noirq
++;
1208 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ
);
1209 dpm_resume_noirq(resume_event(state
));
1211 dpm_show_time(starttime
, state
, "noirq");
1213 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, false);
1218 * device_suspend_late - Execute a "late suspend" callback for given device.
1219 * @dev: Device to handle.
1220 * @state: PM transition of the system being carried out.
1221 * @async: If true, the device is being suspended asynchronously.
1223 * Runtime PM is disabled for @dev while this function is being executed.
1225 static int __device_suspend_late(struct device
*dev
, pm_message_t state
, bool async
)
1227 pm_callback_t callback
= NULL
;
1234 __pm_runtime_disable(dev
, false);
1236 dpm_wait_for_subordinate(dev
, async
);
1241 if (pm_wakeup_pending()) {
1242 async_error
= -EBUSY
;
1246 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1249 if (dev
->pm_domain
) {
1250 info
= "late power domain ";
1251 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
1252 } else if (dev
->type
&& dev
->type
->pm
) {
1253 info
= "late type ";
1254 callback
= pm_late_early_op(dev
->type
->pm
, state
);
1255 } else if (dev
->class && dev
->class->pm
) {
1256 info
= "late class ";
1257 callback
= pm_late_early_op(dev
->class->pm
, state
);
1258 } else if (dev
->bus
&& dev
->bus
->pm
) {
1260 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
1263 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1264 info
= "late driver ";
1265 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
1268 error
= dpm_run_callback(callback
, dev
, state
, info
);
1270 dev
->power
.is_late_suspended
= true;
1272 async_error
= error
;
1275 TRACE_SUSPEND(error
);
1276 complete_all(&dev
->power
.completion
);
1280 static void async_suspend_late(void *data
, async_cookie_t cookie
)
1282 struct device
*dev
= (struct device
*)data
;
1285 error
= __device_suspend_late(dev
, pm_transition
, true);
1287 dpm_save_failed_dev(dev_name(dev
));
1288 pm_dev_err(dev
, pm_transition
, " async", error
);
1293 static int device_suspend_late(struct device
*dev
)
1295 reinit_completion(&dev
->power
.completion
);
1297 if (is_async(dev
)) {
1299 async_schedule(async_suspend_late
, dev
);
1303 return __device_suspend_late(dev
, pm_transition
, false);
1307 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1308 * @state: PM transition of the system being carried out.
1310 int dpm_suspend_late(pm_message_t state
)
1312 ktime_t starttime
= ktime_get();
1315 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, true);
1316 mutex_lock(&dpm_list_mtx
);
1317 pm_transition
= state
;
1320 while (!list_empty(&dpm_suspended_list
)) {
1321 struct device
*dev
= to_device(dpm_suspended_list
.prev
);
1324 mutex_unlock(&dpm_list_mtx
);
1326 error
= device_suspend_late(dev
);
1328 mutex_lock(&dpm_list_mtx
);
1329 if (!list_empty(&dev
->power
.entry
))
1330 list_move(&dev
->power
.entry
, &dpm_late_early_list
);
1333 pm_dev_err(dev
, state
, " late", error
);
1334 dpm_save_failed_dev(dev_name(dev
));
1343 mutex_unlock(&dpm_list_mtx
);
1344 async_synchronize_full();
1346 error
= async_error
;
1348 suspend_stats
.failed_suspend_late
++;
1349 dpm_save_failed_step(SUSPEND_SUSPEND_LATE
);
1350 dpm_resume_early(resume_event(state
));
1352 dpm_show_time(starttime
, state
, "late");
1354 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, false);
1359 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1360 * @state: PM transition of the system being carried out.
1362 int dpm_suspend_end(pm_message_t state
)
1364 int error
= dpm_suspend_late(state
);
1368 error
= dpm_suspend_noirq(state
);
1370 dpm_resume_early(resume_event(state
));
1376 EXPORT_SYMBOL_GPL(dpm_suspend_end
);
1379 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1380 * @dev: Device to suspend.
1381 * @state: PM transition of the system being carried out.
1382 * @cb: Suspend callback to execute.
1383 * @info: string description of caller.
1385 static int legacy_suspend(struct device
*dev
, pm_message_t state
,
1386 int (*cb
)(struct device
*dev
, pm_message_t state
),
1392 calltime
= initcall_debug_start(dev
);
1394 trace_device_pm_callback_start(dev
, info
, state
.event
);
1395 error
= cb(dev
, state
);
1396 trace_device_pm_callback_end(dev
, error
);
1397 suspend_report_result(cb
, error
);
1399 initcall_debug_report(dev
, calltime
, error
, state
, info
);
1404 static void dpm_clear_suppliers_direct_complete(struct device
*dev
)
1406 struct device_link
*link
;
1409 idx
= device_links_read_lock();
1411 list_for_each_entry_rcu(link
, &dev
->links
.suppliers
, c_node
) {
1412 spin_lock_irq(&link
->supplier
->power
.lock
);
1413 link
->supplier
->power
.direct_complete
= false;
1414 spin_unlock_irq(&link
->supplier
->power
.lock
);
1417 device_links_read_unlock(idx
);
1421 * device_suspend - Execute "suspend" callbacks for given device.
1422 * @dev: Device to handle.
1423 * @state: PM transition of the system being carried out.
1424 * @async: If true, the device is being suspended asynchronously.
1426 static int __device_suspend(struct device
*dev
, pm_message_t state
, bool async
)
1428 pm_callback_t callback
= NULL
;
1431 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
1436 dpm_wait_for_subordinate(dev
, async
);
1442 * If a device configured to wake up the system from sleep states
1443 * has been suspended at run time and there's a resume request pending
1444 * for it, this is equivalent to the device signaling wakeup, so the
1445 * system suspend operation should be aborted.
1447 if (pm_runtime_barrier(dev
) && device_may_wakeup(dev
))
1448 pm_wakeup_event(dev
, 0);
1450 if (pm_wakeup_pending()) {
1451 async_error
= -EBUSY
;
1455 if (dev
->power
.syscore
)
1458 if (dev
->power
.direct_complete
) {
1459 if (pm_runtime_status_suspended(dev
)) {
1460 pm_runtime_disable(dev
);
1461 if (pm_runtime_status_suspended(dev
))
1464 pm_runtime_enable(dev
);
1466 dev
->power
.direct_complete
= false;
1469 dpm_watchdog_set(&wd
, dev
);
1472 if (dev
->pm_domain
) {
1473 info
= "power domain ";
1474 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
1478 if (dev
->type
&& dev
->type
->pm
) {
1480 callback
= pm_op(dev
->type
->pm
, state
);
1485 if (dev
->class->pm
) {
1487 callback
= pm_op(dev
->class->pm
, state
);
1489 } else if (dev
->class->suspend
) {
1490 pm_dev_dbg(dev
, state
, "legacy class ");
1491 error
= legacy_suspend(dev
, state
, dev
->class->suspend
,
1500 callback
= pm_op(dev
->bus
->pm
, state
);
1501 } else if (dev
->bus
->suspend
) {
1502 pm_dev_dbg(dev
, state
, "legacy bus ");
1503 error
= legacy_suspend(dev
, state
, dev
->bus
->suspend
,
1510 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1512 callback
= pm_op(dev
->driver
->pm
, state
);
1515 error
= dpm_run_callback(callback
, dev
, state
, info
);
1519 struct device
*parent
= dev
->parent
;
1521 dev
->power
.is_suspended
= true;
1523 spin_lock_irq(&parent
->power
.lock
);
1525 dev
->parent
->power
.direct_complete
= false;
1526 if (dev
->power
.wakeup_path
1527 && !dev
->parent
->power
.ignore_children
)
1528 dev
->parent
->power
.wakeup_path
= true;
1530 spin_unlock_irq(&parent
->power
.lock
);
1532 dpm_clear_suppliers_direct_complete(dev
);
1536 dpm_watchdog_clear(&wd
);
1540 async_error
= error
;
1542 complete_all(&dev
->power
.completion
);
1543 TRACE_SUSPEND(error
);
1547 static void async_suspend(void *data
, async_cookie_t cookie
)
1549 struct device
*dev
= (struct device
*)data
;
1552 error
= __device_suspend(dev
, pm_transition
, true);
1554 dpm_save_failed_dev(dev_name(dev
));
1555 pm_dev_err(dev
, pm_transition
, " async", error
);
1561 static int device_suspend(struct device
*dev
)
1563 reinit_completion(&dev
->power
.completion
);
1565 if (is_async(dev
)) {
1567 async_schedule(async_suspend
, dev
);
1571 return __device_suspend(dev
, pm_transition
, false);
1575 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1576 * @state: PM transition of the system being carried out.
1578 int dpm_suspend(pm_message_t state
)
1580 ktime_t starttime
= ktime_get();
1583 trace_suspend_resume(TPS("dpm_suspend"), state
.event
, true);
1588 mutex_lock(&dpm_list_mtx
);
1589 pm_transition
= state
;
1591 while (!list_empty(&dpm_prepared_list
)) {
1592 struct device
*dev
= to_device(dpm_prepared_list
.prev
);
1595 mutex_unlock(&dpm_list_mtx
);
1597 error
= device_suspend(dev
);
1599 mutex_lock(&dpm_list_mtx
);
1601 pm_dev_err(dev
, state
, "", error
);
1602 dpm_save_failed_dev(dev_name(dev
));
1606 if (!list_empty(&dev
->power
.entry
))
1607 list_move(&dev
->power
.entry
, &dpm_suspended_list
);
1612 mutex_unlock(&dpm_list_mtx
);
1613 async_synchronize_full();
1615 error
= async_error
;
1617 suspend_stats
.failed_suspend
++;
1618 dpm_save_failed_step(SUSPEND_SUSPEND
);
1620 dpm_show_time(starttime
, state
, NULL
);
1621 trace_suspend_resume(TPS("dpm_suspend"), state
.event
, false);
1626 * device_prepare - Prepare a device for system power transition.
1627 * @dev: Device to handle.
1628 * @state: PM transition of the system being carried out.
1630 * Execute the ->prepare() callback(s) for given device. No new children of the
1631 * device may be registered after this function has returned.
1633 static int device_prepare(struct device
*dev
, pm_message_t state
)
1635 int (*callback
)(struct device
*) = NULL
;
1638 if (dev
->power
.syscore
)
1642 * If a device's parent goes into runtime suspend at the wrong time,
1643 * it won't be possible to resume the device. To prevent this we
1644 * block runtime suspend here, during the prepare phase, and allow
1645 * it again during the complete phase.
1647 pm_runtime_get_noresume(dev
);
1651 dev
->power
.wakeup_path
= device_may_wakeup(dev
);
1653 if (dev
->power
.no_pm_callbacks
) {
1654 ret
= 1; /* Let device go direct_complete */
1659 callback
= dev
->pm_domain
->ops
.prepare
;
1660 else if (dev
->type
&& dev
->type
->pm
)
1661 callback
= dev
->type
->pm
->prepare
;
1662 else if (dev
->class && dev
->class->pm
)
1663 callback
= dev
->class->pm
->prepare
;
1664 else if (dev
->bus
&& dev
->bus
->pm
)
1665 callback
= dev
->bus
->pm
->prepare
;
1667 if (!callback
&& dev
->driver
&& dev
->driver
->pm
)
1668 callback
= dev
->driver
->pm
->prepare
;
1671 ret
= callback(dev
);
1677 suspend_report_result(callback
, ret
);
1678 pm_runtime_put(dev
);
1682 * A positive return value from ->prepare() means "this device appears
1683 * to be runtime-suspended and its state is fine, so if it really is
1684 * runtime-suspended, you can leave it in that state provided that you
1685 * will do the same thing with all of its descendants". This only
1686 * applies to suspend transitions, however.
1688 spin_lock_irq(&dev
->power
.lock
);
1689 dev
->power
.direct_complete
= ret
> 0 && state
.event
== PM_EVENT_SUSPEND
;
1690 spin_unlock_irq(&dev
->power
.lock
);
1695 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1696 * @state: PM transition of the system being carried out.
1698 * Execute the ->prepare() callback(s) for all devices.
1700 int dpm_prepare(pm_message_t state
)
1704 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, true);
1708 * Give a chance for the known devices to complete their probes, before
1709 * disable probing of devices. This sync point is important at least
1710 * at boot time + hibernation restore.
1712 wait_for_device_probe();
1714 * It is unsafe if probing of devices will happen during suspend or
1715 * hibernation and system behavior will be unpredictable in this case.
1716 * So, let's prohibit device's probing here and defer their probes
1717 * instead. The normal behavior will be restored in dpm_complete().
1719 device_block_probing();
1721 mutex_lock(&dpm_list_mtx
);
1722 while (!list_empty(&dpm_list
)) {
1723 struct device
*dev
= to_device(dpm_list
.next
);
1726 mutex_unlock(&dpm_list_mtx
);
1728 trace_device_pm_callback_start(dev
, "", state
.event
);
1729 error
= device_prepare(dev
, state
);
1730 trace_device_pm_callback_end(dev
, error
);
1732 mutex_lock(&dpm_list_mtx
);
1734 if (error
== -EAGAIN
) {
1739 printk(KERN_INFO
"PM: Device %s not prepared "
1740 "for power transition: code %d\n",
1741 dev_name(dev
), error
);
1745 dev
->power
.is_prepared
= true;
1746 if (!list_empty(&dev
->power
.entry
))
1747 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
1750 mutex_unlock(&dpm_list_mtx
);
1751 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, false);
1756 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1757 * @state: PM transition of the system being carried out.
1759 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1760 * callbacks for them.
1762 int dpm_suspend_start(pm_message_t state
)
1766 error
= dpm_prepare(state
);
1768 suspend_stats
.failed_prepare
++;
1769 dpm_save_failed_step(SUSPEND_PREPARE
);
1771 error
= dpm_suspend(state
);
1774 EXPORT_SYMBOL_GPL(dpm_suspend_start
);
1776 void __suspend_report_result(const char *function
, void *fn
, int ret
)
1779 printk(KERN_ERR
"%s(): %pF returns %d\n", function
, fn
, ret
);
1781 EXPORT_SYMBOL_GPL(__suspend_report_result
);
1784 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1785 * @dev: Device to wait for.
1786 * @subordinate: Device that needs to wait for @dev.
1788 int device_pm_wait_for_dev(struct device
*subordinate
, struct device
*dev
)
1790 dpm_wait(dev
, subordinate
->power
.async_suspend
);
1793 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev
);
1796 * dpm_for_each_dev - device iterator.
1797 * @data: data for the callback.
1798 * @fn: function to be called for each device.
1800 * Iterate over devices in dpm_list, and call @fn for each device,
1803 void dpm_for_each_dev(void *data
, void (*fn
)(struct device
*, void *))
1811 list_for_each_entry(dev
, &dpm_list
, power
.entry
)
1815 EXPORT_SYMBOL_GPL(dpm_for_each_dev
);
1817 static bool pm_ops_is_empty(const struct dev_pm_ops
*ops
)
1822 return !ops
->prepare
&&
1824 !ops
->suspend_late
&&
1825 !ops
->suspend_noirq
&&
1826 !ops
->resume_noirq
&&
1827 !ops
->resume_early
&&
1832 void device_pm_check_callbacks(struct device
*dev
)
1834 spin_lock_irq(&dev
->power
.lock
);
1835 dev
->power
.no_pm_callbacks
=
1836 (!dev
->bus
|| pm_ops_is_empty(dev
->bus
->pm
)) &&
1837 (!dev
->class || pm_ops_is_empty(dev
->class->pm
)) &&
1838 (!dev
->type
|| pm_ops_is_empty(dev
->type
->pm
)) &&
1839 (!dev
->pm_domain
|| pm_ops_is_empty(&dev
->pm_domain
->ops
)) &&
1840 (!dev
->driver
|| pm_ops_is_empty(dev
->driver
->pm
));
1841 spin_unlock_irq(&dev
->power
.lock
);