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 const 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
,
217 rettime
= ktime_get();
218 nsecs
= (s64
) ktime_to_ns(ktime_sub(rettime
, calltime
));
220 if (pm_print_times_enabled
) {
221 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev
),
222 error
, (unsigned long long)nsecs
>> 10);
227 * dpm_wait - Wait for a PM operation to complete.
228 * @dev: Device to wait for.
229 * @async: If unset, wait only if the device's power.async_suspend flag is set.
231 static void dpm_wait(struct device
*dev
, bool async
)
236 if (async
|| (pm_async_enabled
&& dev
->power
.async_suspend
))
237 wait_for_completion(&dev
->power
.completion
);
240 static int dpm_wait_fn(struct device
*dev
, void *async_ptr
)
242 dpm_wait(dev
, *((bool *)async_ptr
));
246 static void dpm_wait_for_children(struct device
*dev
, bool async
)
248 device_for_each_child(dev
, &async
, dpm_wait_fn
);
251 static void dpm_wait_for_suppliers(struct device
*dev
, bool async
)
253 struct device_link
*link
;
256 idx
= device_links_read_lock();
259 * If the supplier goes away right after we've checked the link to it,
260 * we'll wait for its completion to change the state, but that's fine,
261 * because the only things that will block as a result are the SRCU
262 * callbacks freeing the link objects for the links in the list we're
265 list_for_each_entry_rcu(link
, &dev
->links
.suppliers
, c_node
)
266 if (READ_ONCE(link
->status
) != DL_STATE_DORMANT
)
267 dpm_wait(link
->supplier
, async
);
269 device_links_read_unlock(idx
);
272 static void dpm_wait_for_superior(struct device
*dev
, bool async
)
274 dpm_wait(dev
->parent
, async
);
275 dpm_wait_for_suppliers(dev
, async
);
278 static void dpm_wait_for_consumers(struct device
*dev
, bool async
)
280 struct device_link
*link
;
283 idx
= device_links_read_lock();
286 * The status of a device link can only be changed from "dormant" by a
287 * probe, but that cannot happen during system suspend/resume. In
288 * theory it can change to "dormant" at that time, but then it is
289 * reasonable to wait for the target device anyway (eg. if it goes
290 * away, it's better to wait for it to go away completely and then
291 * continue instead of trying to continue in parallel with its
294 list_for_each_entry_rcu(link
, &dev
->links
.consumers
, s_node
)
295 if (READ_ONCE(link
->status
) != DL_STATE_DORMANT
)
296 dpm_wait(link
->consumer
, async
);
298 device_links_read_unlock(idx
);
301 static void dpm_wait_for_subordinate(struct device
*dev
, bool async
)
303 dpm_wait_for_children(dev
, async
);
304 dpm_wait_for_consumers(dev
, async
);
308 * pm_op - Return the PM operation appropriate for given PM event.
309 * @ops: PM operations to choose from.
310 * @state: PM transition of the system being carried out.
312 static pm_callback_t
pm_op(const struct dev_pm_ops
*ops
, pm_message_t state
)
314 switch (state
.event
) {
315 #ifdef CONFIG_SUSPEND
316 case PM_EVENT_SUSPEND
:
318 case PM_EVENT_RESUME
:
320 #endif /* CONFIG_SUSPEND */
321 #ifdef CONFIG_HIBERNATE_CALLBACKS
322 case PM_EVENT_FREEZE
:
323 case PM_EVENT_QUIESCE
:
325 case PM_EVENT_HIBERNATE
:
326 return ops
->poweroff
;
328 case PM_EVENT_RECOVER
:
331 case PM_EVENT_RESTORE
:
333 #endif /* CONFIG_HIBERNATE_CALLBACKS */
340 * pm_late_early_op - Return the PM operation appropriate for given PM event.
341 * @ops: PM operations to choose from.
342 * @state: PM transition of the system being carried out.
344 * Runtime PM is disabled for @dev while this function is being executed.
346 static pm_callback_t
pm_late_early_op(const struct dev_pm_ops
*ops
,
349 switch (state
.event
) {
350 #ifdef CONFIG_SUSPEND
351 case PM_EVENT_SUSPEND
:
352 return ops
->suspend_late
;
353 case PM_EVENT_RESUME
:
354 return ops
->resume_early
;
355 #endif /* CONFIG_SUSPEND */
356 #ifdef CONFIG_HIBERNATE_CALLBACKS
357 case PM_EVENT_FREEZE
:
358 case PM_EVENT_QUIESCE
:
359 return ops
->freeze_late
;
360 case PM_EVENT_HIBERNATE
:
361 return ops
->poweroff_late
;
363 case PM_EVENT_RECOVER
:
364 return ops
->thaw_early
;
365 case PM_EVENT_RESTORE
:
366 return ops
->restore_early
;
367 #endif /* CONFIG_HIBERNATE_CALLBACKS */
374 * pm_noirq_op - Return the PM operation appropriate for given PM event.
375 * @ops: PM operations to choose from.
376 * @state: PM transition of the system being carried out.
378 * The driver of @dev will not receive interrupts while this function is being
381 static pm_callback_t
pm_noirq_op(const struct dev_pm_ops
*ops
, pm_message_t state
)
383 switch (state
.event
) {
384 #ifdef CONFIG_SUSPEND
385 case PM_EVENT_SUSPEND
:
386 return ops
->suspend_noirq
;
387 case PM_EVENT_RESUME
:
388 return ops
->resume_noirq
;
389 #endif /* CONFIG_SUSPEND */
390 #ifdef CONFIG_HIBERNATE_CALLBACKS
391 case PM_EVENT_FREEZE
:
392 case PM_EVENT_QUIESCE
:
393 return ops
->freeze_noirq
;
394 case PM_EVENT_HIBERNATE
:
395 return ops
->poweroff_noirq
;
397 case PM_EVENT_RECOVER
:
398 return ops
->thaw_noirq
;
399 case PM_EVENT_RESTORE
:
400 return ops
->restore_noirq
;
401 #endif /* CONFIG_HIBERNATE_CALLBACKS */
407 static void pm_dev_dbg(struct device
*dev
, pm_message_t state
, const char *info
)
409 dev_dbg(dev
, "%s%s%s\n", info
, pm_verb(state
.event
),
410 ((state
.event
& PM_EVENT_SLEEP
) && device_may_wakeup(dev
)) ?
411 ", may wakeup" : "");
414 static void pm_dev_err(struct device
*dev
, pm_message_t state
, const char *info
,
417 printk(KERN_ERR
"PM: Device %s failed to %s%s: error %d\n",
418 dev_name(dev
), pm_verb(state
.event
), info
, error
);
421 static void dpm_show_time(ktime_t starttime
, pm_message_t state
, int error
,
428 calltime
= ktime_get();
429 usecs64
= ktime_to_ns(ktime_sub(calltime
, starttime
));
430 do_div(usecs64
, NSEC_PER_USEC
);
435 pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
436 info
?: "", info
? " " : "", pm_verb(state
.event
),
437 error
? "aborted" : "complete",
438 usecs
/ USEC_PER_MSEC
, usecs
% USEC_PER_MSEC
);
441 static int dpm_run_callback(pm_callback_t cb
, struct device
*dev
,
442 pm_message_t state
, const char *info
)
450 calltime
= initcall_debug_start(dev
);
452 pm_dev_dbg(dev
, state
, info
);
453 trace_device_pm_callback_start(dev
, info
, state
.event
);
455 trace_device_pm_callback_end(dev
, error
);
456 suspend_report_result(cb
, error
);
458 initcall_debug_report(dev
, calltime
, error
, state
, info
);
463 #ifdef CONFIG_DPM_WATCHDOG
464 struct dpm_watchdog
{
466 struct task_struct
*tsk
;
467 struct timer_list timer
;
470 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
471 struct dpm_watchdog wd
474 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
475 * @data: Watchdog object address.
477 * Called when a driver has timed out suspending or resuming.
478 * There's not much we can do here to recover so panic() to
479 * capture a crash-dump in pstore.
481 static void dpm_watchdog_handler(unsigned long data
)
483 struct dpm_watchdog
*wd
= (void *)data
;
485 dev_emerg(wd
->dev
, "**** DPM device timeout ****\n");
486 show_stack(wd
->tsk
, NULL
);
487 panic("%s %s: unrecoverable failure\n",
488 dev_driver_string(wd
->dev
), dev_name(wd
->dev
));
492 * dpm_watchdog_set - Enable pm watchdog for given device.
493 * @wd: Watchdog. Must be allocated on the stack.
494 * @dev: Device to handle.
496 static void dpm_watchdog_set(struct dpm_watchdog
*wd
, struct device
*dev
)
498 struct timer_list
*timer
= &wd
->timer
;
503 init_timer_on_stack(timer
);
504 /* use same timeout value for both suspend and resume */
505 timer
->expires
= jiffies
+ HZ
* CONFIG_DPM_WATCHDOG_TIMEOUT
;
506 timer
->function
= dpm_watchdog_handler
;
507 timer
->data
= (unsigned long)wd
;
512 * dpm_watchdog_clear - Disable suspend/resume watchdog.
513 * @wd: Watchdog to disable.
515 static void dpm_watchdog_clear(struct dpm_watchdog
*wd
)
517 struct timer_list
*timer
= &wd
->timer
;
519 del_timer_sync(timer
);
520 destroy_timer_on_stack(timer
);
523 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
524 #define dpm_watchdog_set(x, y)
525 #define dpm_watchdog_clear(x)
528 /*------------------------- Resume routines -------------------------*/
531 * device_resume_noirq - Execute an "early resume" callback for given device.
532 * @dev: Device to handle.
533 * @state: PM transition of the system being carried out.
534 * @async: If true, the device is being resumed asynchronously.
536 * The driver of @dev will not receive interrupts while this function is being
539 static int device_resume_noirq(struct device
*dev
, pm_message_t state
, bool async
)
541 pm_callback_t callback
= NULL
;
542 const char *info
= NULL
;
548 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
551 if (!dev
->power
.is_noirq_suspended
)
554 dpm_wait_for_superior(dev
, async
);
556 if (dev
->pm_domain
) {
557 info
= "noirq power domain ";
558 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
559 } else if (dev
->type
&& dev
->type
->pm
) {
560 info
= "noirq type ";
561 callback
= pm_noirq_op(dev
->type
->pm
, state
);
562 } else if (dev
->class && dev
->class->pm
) {
563 info
= "noirq class ";
564 callback
= pm_noirq_op(dev
->class->pm
, state
);
565 } else if (dev
->bus
&& dev
->bus
->pm
) {
567 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
570 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
571 info
= "noirq driver ";
572 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
575 error
= dpm_run_callback(callback
, dev
, state
, info
);
576 dev
->power
.is_noirq_suspended
= false;
579 complete_all(&dev
->power
.completion
);
584 static bool is_async(struct device
*dev
)
586 return dev
->power
.async_suspend
&& pm_async_enabled
587 && !pm_trace_is_enabled();
590 static void async_resume_noirq(void *data
, async_cookie_t cookie
)
592 struct device
*dev
= (struct device
*)data
;
595 error
= device_resume_noirq(dev
, pm_transition
, true);
597 pm_dev_err(dev
, pm_transition
, " async", error
);
602 void dpm_noirq_resume_devices(pm_message_t state
)
605 ktime_t starttime
= ktime_get();
607 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, true);
608 mutex_lock(&dpm_list_mtx
);
609 pm_transition
= state
;
612 * Advanced the async threads upfront,
613 * in case the starting of async threads is
614 * delayed by non-async resuming devices.
616 list_for_each_entry(dev
, &dpm_noirq_list
, power
.entry
) {
617 reinit_completion(&dev
->power
.completion
);
620 async_schedule(async_resume_noirq
, dev
);
624 while (!list_empty(&dpm_noirq_list
)) {
625 dev
= to_device(dpm_noirq_list
.next
);
627 list_move_tail(&dev
->power
.entry
, &dpm_late_early_list
);
628 mutex_unlock(&dpm_list_mtx
);
630 if (!is_async(dev
)) {
633 error
= device_resume_noirq(dev
, state
, false);
635 suspend_stats
.failed_resume_noirq
++;
636 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ
);
637 dpm_save_failed_dev(dev_name(dev
));
638 pm_dev_err(dev
, state
, " noirq", error
);
642 mutex_lock(&dpm_list_mtx
);
645 mutex_unlock(&dpm_list_mtx
);
646 async_synchronize_full();
647 dpm_show_time(starttime
, state
, 0, "noirq");
648 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, false);
651 void dpm_noirq_end(void)
653 resume_device_irqs();
654 device_wakeup_disarm_wake_irqs();
659 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
660 * @state: PM transition of the system being carried out.
662 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
663 * allow device drivers' interrupt handlers to be called.
665 void dpm_resume_noirq(pm_message_t state
)
667 dpm_noirq_resume_devices(state
);
672 * device_resume_early - Execute an "early resume" callback for given device.
673 * @dev: Device to handle.
674 * @state: PM transition of the system being carried out.
675 * @async: If true, the device is being resumed asynchronously.
677 * Runtime PM is disabled for @dev while this function is being executed.
679 static int device_resume_early(struct device
*dev
, pm_message_t state
, bool async
)
681 pm_callback_t callback
= NULL
;
682 const char *info
= NULL
;
688 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
691 if (!dev
->power
.is_late_suspended
)
694 dpm_wait_for_superior(dev
, async
);
696 if (dev
->pm_domain
) {
697 info
= "early power domain ";
698 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
699 } else if (dev
->type
&& dev
->type
->pm
) {
700 info
= "early type ";
701 callback
= pm_late_early_op(dev
->type
->pm
, state
);
702 } else if (dev
->class && dev
->class->pm
) {
703 info
= "early class ";
704 callback
= pm_late_early_op(dev
->class->pm
, state
);
705 } else if (dev
->bus
&& dev
->bus
->pm
) {
707 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
710 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
711 info
= "early driver ";
712 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
715 error
= dpm_run_callback(callback
, dev
, state
, info
);
716 dev
->power
.is_late_suspended
= false;
721 pm_runtime_enable(dev
);
722 complete_all(&dev
->power
.completion
);
726 static void async_resume_early(void *data
, async_cookie_t cookie
)
728 struct device
*dev
= (struct device
*)data
;
731 error
= device_resume_early(dev
, pm_transition
, true);
733 pm_dev_err(dev
, pm_transition
, " async", error
);
739 * dpm_resume_early - Execute "early resume" callbacks for all devices.
740 * @state: PM transition of the system being carried out.
742 void dpm_resume_early(pm_message_t state
)
745 ktime_t starttime
= ktime_get();
747 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, true);
748 mutex_lock(&dpm_list_mtx
);
749 pm_transition
= state
;
752 * Advanced the async threads upfront,
753 * in case the starting of async threads is
754 * delayed by non-async resuming devices.
756 list_for_each_entry(dev
, &dpm_late_early_list
, power
.entry
) {
757 reinit_completion(&dev
->power
.completion
);
760 async_schedule(async_resume_early
, dev
);
764 while (!list_empty(&dpm_late_early_list
)) {
765 dev
= to_device(dpm_late_early_list
.next
);
767 list_move_tail(&dev
->power
.entry
, &dpm_suspended_list
);
768 mutex_unlock(&dpm_list_mtx
);
770 if (!is_async(dev
)) {
773 error
= device_resume_early(dev
, state
, false);
775 suspend_stats
.failed_resume_early
++;
776 dpm_save_failed_step(SUSPEND_RESUME_EARLY
);
777 dpm_save_failed_dev(dev_name(dev
));
778 pm_dev_err(dev
, state
, " early", error
);
781 mutex_lock(&dpm_list_mtx
);
784 mutex_unlock(&dpm_list_mtx
);
785 async_synchronize_full();
786 dpm_show_time(starttime
, state
, 0, "early");
787 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, false);
791 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
792 * @state: PM transition of the system being carried out.
794 void dpm_resume_start(pm_message_t state
)
796 dpm_resume_noirq(state
);
797 dpm_resume_early(state
);
799 EXPORT_SYMBOL_GPL(dpm_resume_start
);
802 * device_resume - Execute "resume" 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 resumed asynchronously.
807 static int device_resume(struct device
*dev
, pm_message_t state
, bool async
)
809 pm_callback_t callback
= NULL
;
810 const char *info
= NULL
;
812 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
817 if (dev
->power
.syscore
)
820 if (dev
->power
.direct_complete
) {
821 /* Match the pm_runtime_disable() in __device_suspend(). */
822 pm_runtime_enable(dev
);
826 dpm_wait_for_superior(dev
, async
);
827 dpm_watchdog_set(&wd
, dev
);
831 * This is a fib. But we'll allow new children to be added below
832 * a resumed device, even if the device hasn't been completed yet.
834 dev
->power
.is_prepared
= false;
836 if (!dev
->power
.is_suspended
)
839 if (dev
->pm_domain
) {
840 info
= "power domain ";
841 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
845 if (dev
->type
&& dev
->type
->pm
) {
847 callback
= pm_op(dev
->type
->pm
, state
);
852 if (dev
->class->pm
) {
854 callback
= pm_op(dev
->class->pm
, state
);
856 } else if (dev
->class->resume
) {
857 info
= "legacy class ";
858 callback
= dev
->class->resume
;
866 callback
= pm_op(dev
->bus
->pm
, state
);
867 } else if (dev
->bus
->resume
) {
868 info
= "legacy bus ";
869 callback
= dev
->bus
->resume
;
875 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
877 callback
= pm_op(dev
->driver
->pm
, state
);
881 error
= dpm_run_callback(callback
, dev
, state
, info
);
882 dev
->power
.is_suspended
= false;
886 dpm_watchdog_clear(&wd
);
889 complete_all(&dev
->power
.completion
);
896 static void async_resume(void *data
, async_cookie_t cookie
)
898 struct device
*dev
= (struct device
*)data
;
901 error
= device_resume(dev
, pm_transition
, true);
903 pm_dev_err(dev
, pm_transition
, " async", error
);
908 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
909 * @state: PM transition of the system being carried out.
911 * Execute the appropriate "resume" callback for all devices whose status
912 * indicates that they are suspended.
914 void dpm_resume(pm_message_t state
)
917 ktime_t starttime
= ktime_get();
919 trace_suspend_resume(TPS("dpm_resume"), state
.event
, true);
922 mutex_lock(&dpm_list_mtx
);
923 pm_transition
= state
;
926 list_for_each_entry(dev
, &dpm_suspended_list
, power
.entry
) {
927 reinit_completion(&dev
->power
.completion
);
930 async_schedule(async_resume
, dev
);
934 while (!list_empty(&dpm_suspended_list
)) {
935 dev
= to_device(dpm_suspended_list
.next
);
937 if (!is_async(dev
)) {
940 mutex_unlock(&dpm_list_mtx
);
942 error
= device_resume(dev
, state
, false);
944 suspend_stats
.failed_resume
++;
945 dpm_save_failed_step(SUSPEND_RESUME
);
946 dpm_save_failed_dev(dev_name(dev
));
947 pm_dev_err(dev
, state
, "", error
);
950 mutex_lock(&dpm_list_mtx
);
952 if (!list_empty(&dev
->power
.entry
))
953 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
956 mutex_unlock(&dpm_list_mtx
);
957 async_synchronize_full();
958 dpm_show_time(starttime
, state
, 0, NULL
);
961 trace_suspend_resume(TPS("dpm_resume"), state
.event
, false);
965 * device_complete - Complete a PM transition for given device.
966 * @dev: Device to handle.
967 * @state: PM transition of the system being carried out.
969 static void device_complete(struct device
*dev
, pm_message_t state
)
971 void (*callback
)(struct device
*) = NULL
;
972 const char *info
= NULL
;
974 if (dev
->power
.syscore
)
979 if (dev
->pm_domain
) {
980 info
= "completing power domain ";
981 callback
= dev
->pm_domain
->ops
.complete
;
982 } else if (dev
->type
&& dev
->type
->pm
) {
983 info
= "completing type ";
984 callback
= dev
->type
->pm
->complete
;
985 } else if (dev
->class && dev
->class->pm
) {
986 info
= "completing class ";
987 callback
= dev
->class->pm
->complete
;
988 } else if (dev
->bus
&& dev
->bus
->pm
) {
989 info
= "completing bus ";
990 callback
= dev
->bus
->pm
->complete
;
993 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
994 info
= "completing driver ";
995 callback
= dev
->driver
->pm
->complete
;
999 pm_dev_dbg(dev
, state
, info
);
1005 pm_runtime_put(dev
);
1009 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1010 * @state: PM transition of the system being carried out.
1012 * Execute the ->complete() callbacks for all devices whose PM status is not
1013 * DPM_ON (this allows new devices to be registered).
1015 void dpm_complete(pm_message_t state
)
1017 struct list_head list
;
1019 trace_suspend_resume(TPS("dpm_complete"), state
.event
, true);
1022 INIT_LIST_HEAD(&list
);
1023 mutex_lock(&dpm_list_mtx
);
1024 while (!list_empty(&dpm_prepared_list
)) {
1025 struct device
*dev
= to_device(dpm_prepared_list
.prev
);
1028 dev
->power
.is_prepared
= false;
1029 list_move(&dev
->power
.entry
, &list
);
1030 mutex_unlock(&dpm_list_mtx
);
1032 trace_device_pm_callback_start(dev
, "", state
.event
);
1033 device_complete(dev
, state
);
1034 trace_device_pm_callback_end(dev
, 0);
1036 mutex_lock(&dpm_list_mtx
);
1039 list_splice(&list
, &dpm_list
);
1040 mutex_unlock(&dpm_list_mtx
);
1042 /* Allow device probing and trigger re-probing of deferred devices */
1043 device_unblock_probing();
1044 trace_suspend_resume(TPS("dpm_complete"), state
.event
, false);
1048 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1049 * @state: PM transition of the system being carried out.
1051 * Execute "resume" callbacks for all devices and complete the PM transition of
1054 void dpm_resume_end(pm_message_t state
)
1057 dpm_complete(state
);
1059 EXPORT_SYMBOL_GPL(dpm_resume_end
);
1062 /*------------------------- Suspend routines -------------------------*/
1065 * resume_event - Return a "resume" message for given "suspend" sleep state.
1066 * @sleep_state: PM message representing a sleep state.
1068 * Return a PM message representing the resume event corresponding to given
1071 static pm_message_t
resume_event(pm_message_t sleep_state
)
1073 switch (sleep_state
.event
) {
1074 case PM_EVENT_SUSPEND
:
1076 case PM_EVENT_FREEZE
:
1077 case PM_EVENT_QUIESCE
:
1078 return PMSG_RECOVER
;
1079 case PM_EVENT_HIBERNATE
:
1080 return PMSG_RESTORE
;
1086 * device_suspend_noirq - Execute a "late suspend" callback for given device.
1087 * @dev: Device to handle.
1088 * @state: PM transition of the system being carried out.
1089 * @async: If true, the device is being suspended asynchronously.
1091 * The driver of @dev will not receive interrupts while this function is being
1094 static int __device_suspend_noirq(struct device
*dev
, pm_message_t state
, bool async
)
1096 pm_callback_t callback
= NULL
;
1097 const char *info
= NULL
;
1103 dpm_wait_for_subordinate(dev
, async
);
1108 if (pm_wakeup_pending()) {
1109 async_error
= -EBUSY
;
1113 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1116 if (dev
->pm_domain
) {
1117 info
= "noirq power domain ";
1118 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
1119 } else if (dev
->type
&& dev
->type
->pm
) {
1120 info
= "noirq type ";
1121 callback
= pm_noirq_op(dev
->type
->pm
, state
);
1122 } else if (dev
->class && dev
->class->pm
) {
1123 info
= "noirq class ";
1124 callback
= pm_noirq_op(dev
->class->pm
, state
);
1125 } else if (dev
->bus
&& dev
->bus
->pm
) {
1126 info
= "noirq bus ";
1127 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
1130 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1131 info
= "noirq driver ";
1132 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
1135 error
= dpm_run_callback(callback
, dev
, state
, info
);
1137 dev
->power
.is_noirq_suspended
= true;
1139 async_error
= error
;
1142 complete_all(&dev
->power
.completion
);
1143 TRACE_SUSPEND(error
);
1147 static void async_suspend_noirq(void *data
, async_cookie_t cookie
)
1149 struct device
*dev
= (struct device
*)data
;
1152 error
= __device_suspend_noirq(dev
, pm_transition
, true);
1154 dpm_save_failed_dev(dev_name(dev
));
1155 pm_dev_err(dev
, pm_transition
, " async", error
);
1161 static int device_suspend_noirq(struct device
*dev
)
1163 reinit_completion(&dev
->power
.completion
);
1165 if (is_async(dev
)) {
1167 async_schedule(async_suspend_noirq
, dev
);
1170 return __device_suspend_noirq(dev
, pm_transition
, false);
1173 void dpm_noirq_begin(void)
1176 device_wakeup_arm_wake_irqs();
1177 suspend_device_irqs();
1180 int dpm_noirq_suspend_devices(pm_message_t state
)
1182 ktime_t starttime
= ktime_get();
1185 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, true);
1186 mutex_lock(&dpm_list_mtx
);
1187 pm_transition
= state
;
1190 while (!list_empty(&dpm_late_early_list
)) {
1191 struct device
*dev
= to_device(dpm_late_early_list
.prev
);
1194 mutex_unlock(&dpm_list_mtx
);
1196 error
= device_suspend_noirq(dev
);
1198 mutex_lock(&dpm_list_mtx
);
1200 pm_dev_err(dev
, state
, " noirq", error
);
1201 dpm_save_failed_dev(dev_name(dev
));
1205 if (!list_empty(&dev
->power
.entry
))
1206 list_move(&dev
->power
.entry
, &dpm_noirq_list
);
1212 mutex_unlock(&dpm_list_mtx
);
1213 async_synchronize_full();
1215 error
= async_error
;
1218 suspend_stats
.failed_suspend_noirq
++;
1219 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ
);
1221 dpm_show_time(starttime
, state
, error
, "noirq");
1222 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, false);
1227 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1228 * @state: PM transition of the system being carried out.
1230 * Prevent device drivers' interrupt handlers from being called and invoke
1231 * "noirq" suspend callbacks for all non-sysdev devices.
1233 int dpm_suspend_noirq(pm_message_t state
)
1238 ret
= dpm_noirq_suspend_devices(state
);
1240 dpm_resume_noirq(resume_event(state
));
1246 * device_suspend_late - Execute a "late suspend" callback for given device.
1247 * @dev: Device to handle.
1248 * @state: PM transition of the system being carried out.
1249 * @async: If true, the device is being suspended asynchronously.
1251 * Runtime PM is disabled for @dev while this function is being executed.
1253 static int __device_suspend_late(struct device
*dev
, pm_message_t state
, bool async
)
1255 pm_callback_t callback
= NULL
;
1256 const char *info
= NULL
;
1262 __pm_runtime_disable(dev
, false);
1264 dpm_wait_for_subordinate(dev
, async
);
1269 if (pm_wakeup_pending()) {
1270 async_error
= -EBUSY
;
1274 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1277 if (dev
->pm_domain
) {
1278 info
= "late power domain ";
1279 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
1280 } else if (dev
->type
&& dev
->type
->pm
) {
1281 info
= "late type ";
1282 callback
= pm_late_early_op(dev
->type
->pm
, state
);
1283 } else if (dev
->class && dev
->class->pm
) {
1284 info
= "late class ";
1285 callback
= pm_late_early_op(dev
->class->pm
, state
);
1286 } else if (dev
->bus
&& dev
->bus
->pm
) {
1288 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
1291 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1292 info
= "late driver ";
1293 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
1296 error
= dpm_run_callback(callback
, dev
, state
, info
);
1298 dev
->power
.is_late_suspended
= true;
1300 async_error
= error
;
1303 TRACE_SUSPEND(error
);
1304 complete_all(&dev
->power
.completion
);
1308 static void async_suspend_late(void *data
, async_cookie_t cookie
)
1310 struct device
*dev
= (struct device
*)data
;
1313 error
= __device_suspend_late(dev
, pm_transition
, true);
1315 dpm_save_failed_dev(dev_name(dev
));
1316 pm_dev_err(dev
, pm_transition
, " async", error
);
1321 static int device_suspend_late(struct device
*dev
)
1323 reinit_completion(&dev
->power
.completion
);
1325 if (is_async(dev
)) {
1327 async_schedule(async_suspend_late
, dev
);
1331 return __device_suspend_late(dev
, pm_transition
, false);
1335 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1336 * @state: PM transition of the system being carried out.
1338 int dpm_suspend_late(pm_message_t state
)
1340 ktime_t starttime
= ktime_get();
1343 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, true);
1344 mutex_lock(&dpm_list_mtx
);
1345 pm_transition
= state
;
1348 while (!list_empty(&dpm_suspended_list
)) {
1349 struct device
*dev
= to_device(dpm_suspended_list
.prev
);
1352 mutex_unlock(&dpm_list_mtx
);
1354 error
= device_suspend_late(dev
);
1356 mutex_lock(&dpm_list_mtx
);
1357 if (!list_empty(&dev
->power
.entry
))
1358 list_move(&dev
->power
.entry
, &dpm_late_early_list
);
1361 pm_dev_err(dev
, state
, " late", error
);
1362 dpm_save_failed_dev(dev_name(dev
));
1371 mutex_unlock(&dpm_list_mtx
);
1372 async_synchronize_full();
1374 error
= async_error
;
1376 suspend_stats
.failed_suspend_late
++;
1377 dpm_save_failed_step(SUSPEND_SUSPEND_LATE
);
1378 dpm_resume_early(resume_event(state
));
1380 dpm_show_time(starttime
, state
, error
, "late");
1381 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, false);
1386 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1387 * @state: PM transition of the system being carried out.
1389 int dpm_suspend_end(pm_message_t state
)
1391 int error
= dpm_suspend_late(state
);
1395 error
= dpm_suspend_noirq(state
);
1397 dpm_resume_early(resume_event(state
));
1403 EXPORT_SYMBOL_GPL(dpm_suspend_end
);
1406 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1407 * @dev: Device to suspend.
1408 * @state: PM transition of the system being carried out.
1409 * @cb: Suspend callback to execute.
1410 * @info: string description of caller.
1412 static int legacy_suspend(struct device
*dev
, pm_message_t state
,
1413 int (*cb
)(struct device
*dev
, pm_message_t state
),
1419 calltime
= initcall_debug_start(dev
);
1421 trace_device_pm_callback_start(dev
, info
, state
.event
);
1422 error
= cb(dev
, state
);
1423 trace_device_pm_callback_end(dev
, error
);
1424 suspend_report_result(cb
, error
);
1426 initcall_debug_report(dev
, calltime
, error
, state
, info
);
1431 static void dpm_clear_suppliers_direct_complete(struct device
*dev
)
1433 struct device_link
*link
;
1436 idx
= device_links_read_lock();
1438 list_for_each_entry_rcu(link
, &dev
->links
.suppliers
, c_node
) {
1439 spin_lock_irq(&link
->supplier
->power
.lock
);
1440 link
->supplier
->power
.direct_complete
= false;
1441 spin_unlock_irq(&link
->supplier
->power
.lock
);
1444 device_links_read_unlock(idx
);
1448 * device_suspend - Execute "suspend" callbacks for given device.
1449 * @dev: Device to handle.
1450 * @state: PM transition of the system being carried out.
1451 * @async: If true, the device is being suspended asynchronously.
1453 static int __device_suspend(struct device
*dev
, pm_message_t state
, bool async
)
1455 pm_callback_t callback
= NULL
;
1456 const char *info
= NULL
;
1458 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
1463 dpm_wait_for_subordinate(dev
, async
);
1469 * If a device configured to wake up the system from sleep states
1470 * has been suspended at run time and there's a resume request pending
1471 * for it, this is equivalent to the device signaling wakeup, so the
1472 * system suspend operation should be aborted.
1474 if (pm_runtime_barrier(dev
) && device_may_wakeup(dev
))
1475 pm_wakeup_event(dev
, 0);
1477 if (pm_wakeup_pending()) {
1478 async_error
= -EBUSY
;
1482 if (dev
->power
.syscore
)
1485 if (dev
->power
.direct_complete
) {
1486 if (pm_runtime_status_suspended(dev
)) {
1487 pm_runtime_disable(dev
);
1488 if (pm_runtime_status_suspended(dev
))
1491 pm_runtime_enable(dev
);
1493 dev
->power
.direct_complete
= false;
1496 dpm_watchdog_set(&wd
, dev
);
1499 if (dev
->pm_domain
) {
1500 info
= "power domain ";
1501 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
1505 if (dev
->type
&& dev
->type
->pm
) {
1507 callback
= pm_op(dev
->type
->pm
, state
);
1512 if (dev
->class->pm
) {
1514 callback
= pm_op(dev
->class->pm
, state
);
1516 } else if (dev
->class->suspend
) {
1517 pm_dev_dbg(dev
, state
, "legacy class ");
1518 error
= legacy_suspend(dev
, state
, dev
->class->suspend
,
1527 callback
= pm_op(dev
->bus
->pm
, state
);
1528 } else if (dev
->bus
->suspend
) {
1529 pm_dev_dbg(dev
, state
, "legacy bus ");
1530 error
= legacy_suspend(dev
, state
, dev
->bus
->suspend
,
1537 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1539 callback
= pm_op(dev
->driver
->pm
, state
);
1542 error
= dpm_run_callback(callback
, dev
, state
, info
);
1546 struct device
*parent
= dev
->parent
;
1548 dev
->power
.is_suspended
= true;
1550 spin_lock_irq(&parent
->power
.lock
);
1552 dev
->parent
->power
.direct_complete
= false;
1553 if (dev
->power
.wakeup_path
1554 && !dev
->parent
->power
.ignore_children
)
1555 dev
->parent
->power
.wakeup_path
= true;
1557 spin_unlock_irq(&parent
->power
.lock
);
1559 dpm_clear_suppliers_direct_complete(dev
);
1563 dpm_watchdog_clear(&wd
);
1567 async_error
= error
;
1569 complete_all(&dev
->power
.completion
);
1570 TRACE_SUSPEND(error
);
1574 static void async_suspend(void *data
, async_cookie_t cookie
)
1576 struct device
*dev
= (struct device
*)data
;
1579 error
= __device_suspend(dev
, pm_transition
, true);
1581 dpm_save_failed_dev(dev_name(dev
));
1582 pm_dev_err(dev
, pm_transition
, " async", error
);
1588 static int device_suspend(struct device
*dev
)
1590 reinit_completion(&dev
->power
.completion
);
1592 if (is_async(dev
)) {
1594 async_schedule(async_suspend
, dev
);
1598 return __device_suspend(dev
, pm_transition
, false);
1602 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1603 * @state: PM transition of the system being carried out.
1605 int dpm_suspend(pm_message_t state
)
1607 ktime_t starttime
= ktime_get();
1610 trace_suspend_resume(TPS("dpm_suspend"), state
.event
, true);
1615 mutex_lock(&dpm_list_mtx
);
1616 pm_transition
= state
;
1618 while (!list_empty(&dpm_prepared_list
)) {
1619 struct device
*dev
= to_device(dpm_prepared_list
.prev
);
1622 mutex_unlock(&dpm_list_mtx
);
1624 error
= device_suspend(dev
);
1626 mutex_lock(&dpm_list_mtx
);
1628 pm_dev_err(dev
, state
, "", error
);
1629 dpm_save_failed_dev(dev_name(dev
));
1633 if (!list_empty(&dev
->power
.entry
))
1634 list_move(&dev
->power
.entry
, &dpm_suspended_list
);
1639 mutex_unlock(&dpm_list_mtx
);
1640 async_synchronize_full();
1642 error
= async_error
;
1644 suspend_stats
.failed_suspend
++;
1645 dpm_save_failed_step(SUSPEND_SUSPEND
);
1647 dpm_show_time(starttime
, state
, error
, NULL
);
1648 trace_suspend_resume(TPS("dpm_suspend"), state
.event
, false);
1653 * device_prepare - Prepare a device for system power transition.
1654 * @dev: Device to handle.
1655 * @state: PM transition of the system being carried out.
1657 * Execute the ->prepare() callback(s) for given device. No new children of the
1658 * device may be registered after this function has returned.
1660 static int device_prepare(struct device
*dev
, pm_message_t state
)
1662 int (*callback
)(struct device
*) = NULL
;
1665 if (dev
->power
.syscore
)
1669 * If a device's parent goes into runtime suspend at the wrong time,
1670 * it won't be possible to resume the device. To prevent this we
1671 * block runtime suspend here, during the prepare phase, and allow
1672 * it again during the complete phase.
1674 pm_runtime_get_noresume(dev
);
1678 dev
->power
.wakeup_path
= device_may_wakeup(dev
);
1680 if (dev
->power
.no_pm_callbacks
) {
1681 ret
= 1; /* Let device go direct_complete */
1686 callback
= dev
->pm_domain
->ops
.prepare
;
1687 else if (dev
->type
&& dev
->type
->pm
)
1688 callback
= dev
->type
->pm
->prepare
;
1689 else if (dev
->class && dev
->class->pm
)
1690 callback
= dev
->class->pm
->prepare
;
1691 else if (dev
->bus
&& dev
->bus
->pm
)
1692 callback
= dev
->bus
->pm
->prepare
;
1694 if (!callback
&& dev
->driver
&& dev
->driver
->pm
)
1695 callback
= dev
->driver
->pm
->prepare
;
1698 ret
= callback(dev
);
1704 suspend_report_result(callback
, ret
);
1705 pm_runtime_put(dev
);
1709 * A positive return value from ->prepare() means "this device appears
1710 * to be runtime-suspended and its state is fine, so if it really is
1711 * runtime-suspended, you can leave it in that state provided that you
1712 * will do the same thing with all of its descendants". This only
1713 * applies to suspend transitions, however.
1715 spin_lock_irq(&dev
->power
.lock
);
1716 dev
->power
.direct_complete
= ret
> 0 && state
.event
== PM_EVENT_SUSPEND
;
1717 spin_unlock_irq(&dev
->power
.lock
);
1722 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1723 * @state: PM transition of the system being carried out.
1725 * Execute the ->prepare() callback(s) for all devices.
1727 int dpm_prepare(pm_message_t state
)
1731 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, true);
1735 * Give a chance for the known devices to complete their probes, before
1736 * disable probing of devices. This sync point is important at least
1737 * at boot time + hibernation restore.
1739 wait_for_device_probe();
1741 * It is unsafe if probing of devices will happen during suspend or
1742 * hibernation and system behavior will be unpredictable in this case.
1743 * So, let's prohibit device's probing here and defer their probes
1744 * instead. The normal behavior will be restored in dpm_complete().
1746 device_block_probing();
1748 mutex_lock(&dpm_list_mtx
);
1749 while (!list_empty(&dpm_list
)) {
1750 struct device
*dev
= to_device(dpm_list
.next
);
1753 mutex_unlock(&dpm_list_mtx
);
1755 trace_device_pm_callback_start(dev
, "", state
.event
);
1756 error
= device_prepare(dev
, state
);
1757 trace_device_pm_callback_end(dev
, error
);
1759 mutex_lock(&dpm_list_mtx
);
1761 if (error
== -EAGAIN
) {
1766 printk(KERN_INFO
"PM: Device %s not prepared "
1767 "for power transition: code %d\n",
1768 dev_name(dev
), error
);
1772 dev
->power
.is_prepared
= true;
1773 if (!list_empty(&dev
->power
.entry
))
1774 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
1777 mutex_unlock(&dpm_list_mtx
);
1778 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, false);
1783 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1784 * @state: PM transition of the system being carried out.
1786 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1787 * callbacks for them.
1789 int dpm_suspend_start(pm_message_t state
)
1793 error
= dpm_prepare(state
);
1795 suspend_stats
.failed_prepare
++;
1796 dpm_save_failed_step(SUSPEND_PREPARE
);
1798 error
= dpm_suspend(state
);
1801 EXPORT_SYMBOL_GPL(dpm_suspend_start
);
1803 void __suspend_report_result(const char *function
, void *fn
, int ret
)
1806 printk(KERN_ERR
"%s(): %pF returns %d\n", function
, fn
, ret
);
1808 EXPORT_SYMBOL_GPL(__suspend_report_result
);
1811 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1812 * @dev: Device to wait for.
1813 * @subordinate: Device that needs to wait for @dev.
1815 int device_pm_wait_for_dev(struct device
*subordinate
, struct device
*dev
)
1817 dpm_wait(dev
, subordinate
->power
.async_suspend
);
1820 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev
);
1823 * dpm_for_each_dev - device iterator.
1824 * @data: data for the callback.
1825 * @fn: function to be called for each device.
1827 * Iterate over devices in dpm_list, and call @fn for each device,
1830 void dpm_for_each_dev(void *data
, void (*fn
)(struct device
*, void *))
1838 list_for_each_entry(dev
, &dpm_list
, power
.entry
)
1842 EXPORT_SYMBOL_GPL(dpm_for_each_dev
);
1844 static bool pm_ops_is_empty(const struct dev_pm_ops
*ops
)
1849 return !ops
->prepare
&&
1851 !ops
->suspend_late
&&
1852 !ops
->suspend_noirq
&&
1853 !ops
->resume_noirq
&&
1854 !ops
->resume_early
&&
1859 void device_pm_check_callbacks(struct device
*dev
)
1861 spin_lock_irq(&dev
->power
.lock
);
1862 dev
->power
.no_pm_callbacks
=
1863 (!dev
->bus
|| (pm_ops_is_empty(dev
->bus
->pm
) &&
1864 !dev
->bus
->suspend
&& !dev
->bus
->resume
)) &&
1865 (!dev
->class || (pm_ops_is_empty(dev
->class->pm
) &&
1866 !dev
->class->suspend
&& !dev
->class->resume
)) &&
1867 (!dev
->type
|| pm_ops_is_empty(dev
->type
->pm
)) &&
1868 (!dev
->pm_domain
|| pm_ops_is_empty(&dev
->pm_domain
->ops
)) &&
1869 (!dev
->driver
|| (pm_ops_is_empty(dev
->driver
->pm
) &&
1870 !dev
->driver
->suspend
&& !dev
->driver
->resume
));
1871 spin_unlock_irq(&dev
->power
.lock
);