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(struct timer_list
*t
)
483 struct dpm_watchdog
*wd
= from_timer(wd
, t
, timer
);
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 timer_setup_on_stack(timer
, dpm_watchdog_handler
, 0);
504 /* use same timeout value for both suspend and resume */
505 timer
->expires
= jiffies
+ HZ
* CONFIG_DPM_WATCHDOG_TIMEOUT
;
510 * dpm_watchdog_clear - Disable suspend/resume watchdog.
511 * @wd: Watchdog to disable.
513 static void dpm_watchdog_clear(struct dpm_watchdog
*wd
)
515 struct timer_list
*timer
= &wd
->timer
;
517 del_timer_sync(timer
);
518 destroy_timer_on_stack(timer
);
521 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
522 #define dpm_watchdog_set(x, y)
523 #define dpm_watchdog_clear(x)
526 /*------------------------- Resume routines -------------------------*/
529 * dev_pm_skip_next_resume_phases - Skip next system resume phases for device.
530 * @dev: Target device.
532 * Make the core skip the "early resume" and "resume" phases for @dev.
534 * This function can be called by middle-layer code during the "noirq" phase of
535 * system resume if necessary, but not by device drivers.
537 void dev_pm_skip_next_resume_phases(struct device
*dev
)
539 dev
->power
.is_late_suspended
= false;
540 dev
->power
.is_suspended
= false;
544 * device_resume_noirq - Execute a "noirq resume" callback for given device.
545 * @dev: Device to handle.
546 * @state: PM transition of the system being carried out.
547 * @async: If true, the device is being resumed asynchronously.
549 * The driver of @dev will not receive interrupts while this function is being
552 static int device_resume_noirq(struct device
*dev
, pm_message_t state
, bool async
)
554 pm_callback_t callback
= NULL
;
555 const char *info
= NULL
;
561 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
564 if (!dev
->power
.is_noirq_suspended
)
567 dpm_wait_for_superior(dev
, async
);
569 if (dev
->pm_domain
) {
570 info
= "noirq power domain ";
571 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
572 } else if (dev
->type
&& dev
->type
->pm
) {
573 info
= "noirq type ";
574 callback
= pm_noirq_op(dev
->type
->pm
, state
);
575 } else if (dev
->class && dev
->class->pm
) {
576 info
= "noirq class ";
577 callback
= pm_noirq_op(dev
->class->pm
, state
);
578 } else if (dev
->bus
&& dev
->bus
->pm
) {
580 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
583 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
584 info
= "noirq driver ";
585 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
588 error
= dpm_run_callback(callback
, dev
, state
, info
);
589 dev
->power
.is_noirq_suspended
= false;
592 complete_all(&dev
->power
.completion
);
597 static bool is_async(struct device
*dev
)
599 return dev
->power
.async_suspend
&& pm_async_enabled
600 && !pm_trace_is_enabled();
603 static void async_resume_noirq(void *data
, async_cookie_t cookie
)
605 struct device
*dev
= (struct device
*)data
;
608 error
= device_resume_noirq(dev
, pm_transition
, true);
610 pm_dev_err(dev
, pm_transition
, " async", error
);
615 void dpm_noirq_resume_devices(pm_message_t state
)
618 ktime_t starttime
= ktime_get();
620 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, true);
621 mutex_lock(&dpm_list_mtx
);
622 pm_transition
= state
;
625 * Advanced the async threads upfront,
626 * in case the starting of async threads is
627 * delayed by non-async resuming devices.
629 list_for_each_entry(dev
, &dpm_noirq_list
, power
.entry
) {
630 reinit_completion(&dev
->power
.completion
);
633 async_schedule(async_resume_noirq
, dev
);
637 while (!list_empty(&dpm_noirq_list
)) {
638 dev
= to_device(dpm_noirq_list
.next
);
640 list_move_tail(&dev
->power
.entry
, &dpm_late_early_list
);
641 mutex_unlock(&dpm_list_mtx
);
643 if (!is_async(dev
)) {
646 error
= device_resume_noirq(dev
, state
, false);
648 suspend_stats
.failed_resume_noirq
++;
649 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ
);
650 dpm_save_failed_dev(dev_name(dev
));
651 pm_dev_err(dev
, state
, " noirq", error
);
655 mutex_lock(&dpm_list_mtx
);
658 mutex_unlock(&dpm_list_mtx
);
659 async_synchronize_full();
660 dpm_show_time(starttime
, state
, 0, "noirq");
661 trace_suspend_resume(TPS("dpm_resume_noirq"), state
.event
, false);
664 void dpm_noirq_end(void)
666 resume_device_irqs();
667 device_wakeup_disarm_wake_irqs();
672 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
673 * @state: PM transition of the system being carried out.
675 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
676 * allow device drivers' interrupt handlers to be called.
678 void dpm_resume_noirq(pm_message_t state
)
680 dpm_noirq_resume_devices(state
);
685 * device_resume_early - Execute an "early resume" callback for given device.
686 * @dev: Device to handle.
687 * @state: PM transition of the system being carried out.
688 * @async: If true, the device is being resumed asynchronously.
690 * Runtime PM is disabled for @dev while this function is being executed.
692 static int device_resume_early(struct device
*dev
, pm_message_t state
, bool async
)
694 pm_callback_t callback
= NULL
;
695 const char *info
= NULL
;
701 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
704 if (!dev
->power
.is_late_suspended
)
707 dpm_wait_for_superior(dev
, async
);
709 if (dev
->pm_domain
) {
710 info
= "early power domain ";
711 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
712 } else if (dev
->type
&& dev
->type
->pm
) {
713 info
= "early type ";
714 callback
= pm_late_early_op(dev
->type
->pm
, state
);
715 } else if (dev
->class && dev
->class->pm
) {
716 info
= "early class ";
717 callback
= pm_late_early_op(dev
->class->pm
, state
);
718 } else if (dev
->bus
&& dev
->bus
->pm
) {
720 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
723 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
724 info
= "early driver ";
725 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
728 error
= dpm_run_callback(callback
, dev
, state
, info
);
729 dev
->power
.is_late_suspended
= false;
734 pm_runtime_enable(dev
);
735 complete_all(&dev
->power
.completion
);
739 static void async_resume_early(void *data
, async_cookie_t cookie
)
741 struct device
*dev
= (struct device
*)data
;
744 error
= device_resume_early(dev
, pm_transition
, true);
746 pm_dev_err(dev
, pm_transition
, " async", error
);
752 * dpm_resume_early - Execute "early resume" callbacks for all devices.
753 * @state: PM transition of the system being carried out.
755 void dpm_resume_early(pm_message_t state
)
758 ktime_t starttime
= ktime_get();
760 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, true);
761 mutex_lock(&dpm_list_mtx
);
762 pm_transition
= state
;
765 * Advanced the async threads upfront,
766 * in case the starting of async threads is
767 * delayed by non-async resuming devices.
769 list_for_each_entry(dev
, &dpm_late_early_list
, power
.entry
) {
770 reinit_completion(&dev
->power
.completion
);
773 async_schedule(async_resume_early
, dev
);
777 while (!list_empty(&dpm_late_early_list
)) {
778 dev
= to_device(dpm_late_early_list
.next
);
780 list_move_tail(&dev
->power
.entry
, &dpm_suspended_list
);
781 mutex_unlock(&dpm_list_mtx
);
783 if (!is_async(dev
)) {
786 error
= device_resume_early(dev
, state
, false);
788 suspend_stats
.failed_resume_early
++;
789 dpm_save_failed_step(SUSPEND_RESUME_EARLY
);
790 dpm_save_failed_dev(dev_name(dev
));
791 pm_dev_err(dev
, state
, " early", error
);
794 mutex_lock(&dpm_list_mtx
);
797 mutex_unlock(&dpm_list_mtx
);
798 async_synchronize_full();
799 dpm_show_time(starttime
, state
, 0, "early");
800 trace_suspend_resume(TPS("dpm_resume_early"), state
.event
, false);
804 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
805 * @state: PM transition of the system being carried out.
807 void dpm_resume_start(pm_message_t state
)
809 dpm_resume_noirq(state
);
810 dpm_resume_early(state
);
812 EXPORT_SYMBOL_GPL(dpm_resume_start
);
815 * device_resume - Execute "resume" callbacks for given device.
816 * @dev: Device to handle.
817 * @state: PM transition of the system being carried out.
818 * @async: If true, the device is being resumed asynchronously.
820 static int device_resume(struct device
*dev
, pm_message_t state
, bool async
)
822 pm_callback_t callback
= NULL
;
823 const char *info
= NULL
;
825 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
830 if (dev
->power
.syscore
)
833 if (dev
->power
.direct_complete
) {
834 /* Match the pm_runtime_disable() in __device_suspend(). */
835 pm_runtime_enable(dev
);
839 dpm_wait_for_superior(dev
, async
);
840 dpm_watchdog_set(&wd
, dev
);
844 * This is a fib. But we'll allow new children to be added below
845 * a resumed device, even if the device hasn't been completed yet.
847 dev
->power
.is_prepared
= false;
849 if (!dev
->power
.is_suspended
)
852 if (dev
->pm_domain
) {
853 info
= "power domain ";
854 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
858 if (dev
->type
&& dev
->type
->pm
) {
860 callback
= pm_op(dev
->type
->pm
, state
);
864 if (dev
->class && dev
->class->pm
) {
866 callback
= pm_op(dev
->class->pm
, state
);
873 callback
= pm_op(dev
->bus
->pm
, state
);
874 } else if (dev
->bus
->resume
) {
875 info
= "legacy bus ";
876 callback
= dev
->bus
->resume
;
882 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
884 callback
= pm_op(dev
->driver
->pm
, state
);
888 error
= dpm_run_callback(callback
, dev
, state
, info
);
889 dev
->power
.is_suspended
= false;
893 dpm_watchdog_clear(&wd
);
896 complete_all(&dev
->power
.completion
);
903 static void async_resume(void *data
, async_cookie_t cookie
)
905 struct device
*dev
= (struct device
*)data
;
908 error
= device_resume(dev
, pm_transition
, true);
910 pm_dev_err(dev
, pm_transition
, " async", error
);
915 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
916 * @state: PM transition of the system being carried out.
918 * Execute the appropriate "resume" callback for all devices whose status
919 * indicates that they are suspended.
921 void dpm_resume(pm_message_t state
)
924 ktime_t starttime
= ktime_get();
926 trace_suspend_resume(TPS("dpm_resume"), state
.event
, true);
929 mutex_lock(&dpm_list_mtx
);
930 pm_transition
= state
;
933 list_for_each_entry(dev
, &dpm_suspended_list
, power
.entry
) {
934 reinit_completion(&dev
->power
.completion
);
937 async_schedule(async_resume
, dev
);
941 while (!list_empty(&dpm_suspended_list
)) {
942 dev
= to_device(dpm_suspended_list
.next
);
944 if (!is_async(dev
)) {
947 mutex_unlock(&dpm_list_mtx
);
949 error
= device_resume(dev
, state
, false);
951 suspend_stats
.failed_resume
++;
952 dpm_save_failed_step(SUSPEND_RESUME
);
953 dpm_save_failed_dev(dev_name(dev
));
954 pm_dev_err(dev
, state
, "", error
);
957 mutex_lock(&dpm_list_mtx
);
959 if (!list_empty(&dev
->power
.entry
))
960 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
963 mutex_unlock(&dpm_list_mtx
);
964 async_synchronize_full();
965 dpm_show_time(starttime
, state
, 0, NULL
);
968 trace_suspend_resume(TPS("dpm_resume"), state
.event
, false);
972 * device_complete - Complete a PM transition for given device.
973 * @dev: Device to handle.
974 * @state: PM transition of the system being carried out.
976 static void device_complete(struct device
*dev
, pm_message_t state
)
978 void (*callback
)(struct device
*) = NULL
;
979 const char *info
= NULL
;
981 if (dev
->power
.syscore
)
986 if (dev
->pm_domain
) {
987 info
= "completing power domain ";
988 callback
= dev
->pm_domain
->ops
.complete
;
989 } else if (dev
->type
&& dev
->type
->pm
) {
990 info
= "completing type ";
991 callback
= dev
->type
->pm
->complete
;
992 } else if (dev
->class && dev
->class->pm
) {
993 info
= "completing class ";
994 callback
= dev
->class->pm
->complete
;
995 } else if (dev
->bus
&& dev
->bus
->pm
) {
996 info
= "completing bus ";
997 callback
= dev
->bus
->pm
->complete
;
1000 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1001 info
= "completing driver ";
1002 callback
= dev
->driver
->pm
->complete
;
1006 pm_dev_dbg(dev
, state
, info
);
1012 pm_runtime_put(dev
);
1016 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1017 * @state: PM transition of the system being carried out.
1019 * Execute the ->complete() callbacks for all devices whose PM status is not
1020 * DPM_ON (this allows new devices to be registered).
1022 void dpm_complete(pm_message_t state
)
1024 struct list_head list
;
1026 trace_suspend_resume(TPS("dpm_complete"), state
.event
, true);
1029 INIT_LIST_HEAD(&list
);
1030 mutex_lock(&dpm_list_mtx
);
1031 while (!list_empty(&dpm_prepared_list
)) {
1032 struct device
*dev
= to_device(dpm_prepared_list
.prev
);
1035 dev
->power
.is_prepared
= false;
1036 list_move(&dev
->power
.entry
, &list
);
1037 mutex_unlock(&dpm_list_mtx
);
1039 trace_device_pm_callback_start(dev
, "", state
.event
);
1040 device_complete(dev
, state
);
1041 trace_device_pm_callback_end(dev
, 0);
1043 mutex_lock(&dpm_list_mtx
);
1046 list_splice(&list
, &dpm_list
);
1047 mutex_unlock(&dpm_list_mtx
);
1049 /* Allow device probing and trigger re-probing of deferred devices */
1050 device_unblock_probing();
1051 trace_suspend_resume(TPS("dpm_complete"), state
.event
, false);
1055 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1056 * @state: PM transition of the system being carried out.
1058 * Execute "resume" callbacks for all devices and complete the PM transition of
1061 void dpm_resume_end(pm_message_t state
)
1064 dpm_complete(state
);
1066 EXPORT_SYMBOL_GPL(dpm_resume_end
);
1069 /*------------------------- Suspend routines -------------------------*/
1072 * resume_event - Return a "resume" message for given "suspend" sleep state.
1073 * @sleep_state: PM message representing a sleep state.
1075 * Return a PM message representing the resume event corresponding to given
1078 static pm_message_t
resume_event(pm_message_t sleep_state
)
1080 switch (sleep_state
.event
) {
1081 case PM_EVENT_SUSPEND
:
1083 case PM_EVENT_FREEZE
:
1084 case PM_EVENT_QUIESCE
:
1085 return PMSG_RECOVER
;
1086 case PM_EVENT_HIBERNATE
:
1087 return PMSG_RESTORE
;
1093 * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1094 * @dev: Device to handle.
1095 * @state: PM transition of the system being carried out.
1096 * @async: If true, the device is being suspended asynchronously.
1098 * The driver of @dev will not receive interrupts while this function is being
1101 static int __device_suspend_noirq(struct device
*dev
, pm_message_t state
, bool async
)
1103 pm_callback_t callback
= NULL
;
1104 const char *info
= NULL
;
1110 dpm_wait_for_subordinate(dev
, async
);
1115 if (pm_wakeup_pending()) {
1116 async_error
= -EBUSY
;
1120 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1123 if (dev
->pm_domain
) {
1124 info
= "noirq power domain ";
1125 callback
= pm_noirq_op(&dev
->pm_domain
->ops
, state
);
1126 } else if (dev
->type
&& dev
->type
->pm
) {
1127 info
= "noirq type ";
1128 callback
= pm_noirq_op(dev
->type
->pm
, state
);
1129 } else if (dev
->class && dev
->class->pm
) {
1130 info
= "noirq class ";
1131 callback
= pm_noirq_op(dev
->class->pm
, state
);
1132 } else if (dev
->bus
&& dev
->bus
->pm
) {
1133 info
= "noirq bus ";
1134 callback
= pm_noirq_op(dev
->bus
->pm
, state
);
1137 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1138 info
= "noirq driver ";
1139 callback
= pm_noirq_op(dev
->driver
->pm
, state
);
1142 error
= dpm_run_callback(callback
, dev
, state
, info
);
1144 dev
->power
.is_noirq_suspended
= true;
1146 async_error
= error
;
1149 complete_all(&dev
->power
.completion
);
1150 TRACE_SUSPEND(error
);
1154 static void async_suspend_noirq(void *data
, async_cookie_t cookie
)
1156 struct device
*dev
= (struct device
*)data
;
1159 error
= __device_suspend_noirq(dev
, pm_transition
, true);
1161 dpm_save_failed_dev(dev_name(dev
));
1162 pm_dev_err(dev
, pm_transition
, " async", error
);
1168 static int device_suspend_noirq(struct device
*dev
)
1170 reinit_completion(&dev
->power
.completion
);
1172 if (is_async(dev
)) {
1174 async_schedule(async_suspend_noirq
, dev
);
1177 return __device_suspend_noirq(dev
, pm_transition
, false);
1180 void dpm_noirq_begin(void)
1183 device_wakeup_arm_wake_irqs();
1184 suspend_device_irqs();
1187 int dpm_noirq_suspend_devices(pm_message_t state
)
1189 ktime_t starttime
= ktime_get();
1192 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, true);
1193 mutex_lock(&dpm_list_mtx
);
1194 pm_transition
= state
;
1197 while (!list_empty(&dpm_late_early_list
)) {
1198 struct device
*dev
= to_device(dpm_late_early_list
.prev
);
1201 mutex_unlock(&dpm_list_mtx
);
1203 error
= device_suspend_noirq(dev
);
1205 mutex_lock(&dpm_list_mtx
);
1207 pm_dev_err(dev
, state
, " noirq", error
);
1208 dpm_save_failed_dev(dev_name(dev
));
1212 if (!list_empty(&dev
->power
.entry
))
1213 list_move(&dev
->power
.entry
, &dpm_noirq_list
);
1219 mutex_unlock(&dpm_list_mtx
);
1220 async_synchronize_full();
1222 error
= async_error
;
1225 suspend_stats
.failed_suspend_noirq
++;
1226 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ
);
1228 dpm_show_time(starttime
, state
, error
, "noirq");
1229 trace_suspend_resume(TPS("dpm_suspend_noirq"), state
.event
, false);
1234 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1235 * @state: PM transition of the system being carried out.
1237 * Prevent device drivers' interrupt handlers from being called and invoke
1238 * "noirq" suspend callbacks for all non-sysdev devices.
1240 int dpm_suspend_noirq(pm_message_t state
)
1245 ret
= dpm_noirq_suspend_devices(state
);
1247 dpm_resume_noirq(resume_event(state
));
1253 * __device_suspend_late - Execute a "late suspend" callback for given device.
1254 * @dev: Device to handle.
1255 * @state: PM transition of the system being carried out.
1256 * @async: If true, the device is being suspended asynchronously.
1258 * Runtime PM is disabled for @dev while this function is being executed.
1260 static int __device_suspend_late(struct device
*dev
, pm_message_t state
, bool async
)
1262 pm_callback_t callback
= NULL
;
1263 const char *info
= NULL
;
1269 __pm_runtime_disable(dev
, false);
1271 dpm_wait_for_subordinate(dev
, async
);
1276 if (pm_wakeup_pending()) {
1277 async_error
= -EBUSY
;
1281 if (dev
->power
.syscore
|| dev
->power
.direct_complete
)
1284 if (dev
->pm_domain
) {
1285 info
= "late power domain ";
1286 callback
= pm_late_early_op(&dev
->pm_domain
->ops
, state
);
1287 } else if (dev
->type
&& dev
->type
->pm
) {
1288 info
= "late type ";
1289 callback
= pm_late_early_op(dev
->type
->pm
, state
);
1290 } else if (dev
->class && dev
->class->pm
) {
1291 info
= "late class ";
1292 callback
= pm_late_early_op(dev
->class->pm
, state
);
1293 } else if (dev
->bus
&& dev
->bus
->pm
) {
1295 callback
= pm_late_early_op(dev
->bus
->pm
, state
);
1298 if (!callback
&& dev
->driver
&& dev
->driver
->pm
) {
1299 info
= "late driver ";
1300 callback
= pm_late_early_op(dev
->driver
->pm
, state
);
1303 error
= dpm_run_callback(callback
, dev
, state
, info
);
1305 dev
->power
.is_late_suspended
= true;
1307 async_error
= error
;
1310 TRACE_SUSPEND(error
);
1311 complete_all(&dev
->power
.completion
);
1315 static void async_suspend_late(void *data
, async_cookie_t cookie
)
1317 struct device
*dev
= (struct device
*)data
;
1320 error
= __device_suspend_late(dev
, pm_transition
, true);
1322 dpm_save_failed_dev(dev_name(dev
));
1323 pm_dev_err(dev
, pm_transition
, " async", error
);
1328 static int device_suspend_late(struct device
*dev
)
1330 reinit_completion(&dev
->power
.completion
);
1332 if (is_async(dev
)) {
1334 async_schedule(async_suspend_late
, dev
);
1338 return __device_suspend_late(dev
, pm_transition
, false);
1342 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1343 * @state: PM transition of the system being carried out.
1345 int dpm_suspend_late(pm_message_t state
)
1347 ktime_t starttime
= ktime_get();
1350 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, true);
1351 mutex_lock(&dpm_list_mtx
);
1352 pm_transition
= state
;
1355 while (!list_empty(&dpm_suspended_list
)) {
1356 struct device
*dev
= to_device(dpm_suspended_list
.prev
);
1359 mutex_unlock(&dpm_list_mtx
);
1361 error
= device_suspend_late(dev
);
1363 mutex_lock(&dpm_list_mtx
);
1364 if (!list_empty(&dev
->power
.entry
))
1365 list_move(&dev
->power
.entry
, &dpm_late_early_list
);
1368 pm_dev_err(dev
, state
, " late", error
);
1369 dpm_save_failed_dev(dev_name(dev
));
1378 mutex_unlock(&dpm_list_mtx
);
1379 async_synchronize_full();
1381 error
= async_error
;
1383 suspend_stats
.failed_suspend_late
++;
1384 dpm_save_failed_step(SUSPEND_SUSPEND_LATE
);
1385 dpm_resume_early(resume_event(state
));
1387 dpm_show_time(starttime
, state
, error
, "late");
1388 trace_suspend_resume(TPS("dpm_suspend_late"), state
.event
, false);
1393 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1394 * @state: PM transition of the system being carried out.
1396 int dpm_suspend_end(pm_message_t state
)
1398 int error
= dpm_suspend_late(state
);
1402 error
= dpm_suspend_noirq(state
);
1404 dpm_resume_early(resume_event(state
));
1410 EXPORT_SYMBOL_GPL(dpm_suspend_end
);
1413 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1414 * @dev: Device to suspend.
1415 * @state: PM transition of the system being carried out.
1416 * @cb: Suspend callback to execute.
1417 * @info: string description of caller.
1419 static int legacy_suspend(struct device
*dev
, pm_message_t state
,
1420 int (*cb
)(struct device
*dev
, pm_message_t state
),
1426 calltime
= initcall_debug_start(dev
);
1428 trace_device_pm_callback_start(dev
, info
, state
.event
);
1429 error
= cb(dev
, state
);
1430 trace_device_pm_callback_end(dev
, error
);
1431 suspend_report_result(cb
, error
);
1433 initcall_debug_report(dev
, calltime
, error
, state
, info
);
1438 static void dpm_clear_suppliers_direct_complete(struct device
*dev
)
1440 struct device_link
*link
;
1443 idx
= device_links_read_lock();
1445 list_for_each_entry_rcu(link
, &dev
->links
.suppliers
, c_node
) {
1446 spin_lock_irq(&link
->supplier
->power
.lock
);
1447 link
->supplier
->power
.direct_complete
= false;
1448 spin_unlock_irq(&link
->supplier
->power
.lock
);
1451 device_links_read_unlock(idx
);
1455 * __device_suspend - Execute "suspend" callbacks for given device.
1456 * @dev: Device to handle.
1457 * @state: PM transition of the system being carried out.
1458 * @async: If true, the device is being suspended asynchronously.
1460 static int __device_suspend(struct device
*dev
, pm_message_t state
, bool async
)
1462 pm_callback_t callback
= NULL
;
1463 const char *info
= NULL
;
1465 DECLARE_DPM_WATCHDOG_ON_STACK(wd
);
1470 dpm_wait_for_subordinate(dev
, async
);
1476 * If a device configured to wake up the system from sleep states
1477 * has been suspended at run time and there's a resume request pending
1478 * for it, this is equivalent to the device signaling wakeup, so the
1479 * system suspend operation should be aborted.
1481 if (pm_runtime_barrier(dev
) && device_may_wakeup(dev
))
1482 pm_wakeup_event(dev
, 0);
1484 if (pm_wakeup_pending()) {
1485 async_error
= -EBUSY
;
1489 if (dev
->power
.syscore
)
1492 if (dev
->power
.direct_complete
) {
1493 if (pm_runtime_status_suspended(dev
)) {
1494 pm_runtime_disable(dev
);
1495 if (pm_runtime_status_suspended(dev
))
1498 pm_runtime_enable(dev
);
1500 dev
->power
.direct_complete
= false;
1503 dpm_watchdog_set(&wd
, dev
);
1506 if (dev
->pm_domain
) {
1507 info
= "power domain ";
1508 callback
= pm_op(&dev
->pm_domain
->ops
, state
);
1512 if (dev
->type
&& dev
->type
->pm
) {
1514 callback
= pm_op(dev
->type
->pm
, state
);
1518 if (dev
->class && dev
->class->pm
) {
1520 callback
= pm_op(dev
->class->pm
, state
);
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
)
1668 WARN_ON(dev_pm_test_driver_flags(dev
, DPM_FLAG_SMART_SUSPEND
) &&
1669 !pm_runtime_enabled(dev
));
1672 * If a device's parent goes into runtime suspend at the wrong time,
1673 * it won't be possible to resume the device. To prevent this we
1674 * block runtime suspend here, during the prepare phase, and allow
1675 * it again during the complete phase.
1677 pm_runtime_get_noresume(dev
);
1681 dev
->power
.wakeup_path
= device_may_wakeup(dev
);
1683 if (dev
->power
.no_pm_callbacks
) {
1684 ret
= 1; /* Let device go direct_complete */
1689 callback
= dev
->pm_domain
->ops
.prepare
;
1690 else if (dev
->type
&& dev
->type
->pm
)
1691 callback
= dev
->type
->pm
->prepare
;
1692 else if (dev
->class && dev
->class->pm
)
1693 callback
= dev
->class->pm
->prepare
;
1694 else if (dev
->bus
&& dev
->bus
->pm
)
1695 callback
= dev
->bus
->pm
->prepare
;
1697 if (!callback
&& dev
->driver
&& dev
->driver
->pm
)
1698 callback
= dev
->driver
->pm
->prepare
;
1701 ret
= callback(dev
);
1707 suspend_report_result(callback
, ret
);
1708 pm_runtime_put(dev
);
1712 * A positive return value from ->prepare() means "this device appears
1713 * to be runtime-suspended and its state is fine, so if it really is
1714 * runtime-suspended, you can leave it in that state provided that you
1715 * will do the same thing with all of its descendants". This only
1716 * applies to suspend transitions, however.
1718 spin_lock_irq(&dev
->power
.lock
);
1719 dev
->power
.direct_complete
= state
.event
== PM_EVENT_SUSPEND
&&
1720 pm_runtime_suspended(dev
) && ret
> 0 &&
1721 !dev_pm_test_driver_flags(dev
, DPM_FLAG_NEVER_SKIP
);
1722 spin_unlock_irq(&dev
->power
.lock
);
1727 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1728 * @state: PM transition of the system being carried out.
1730 * Execute the ->prepare() callback(s) for all devices.
1732 int dpm_prepare(pm_message_t state
)
1736 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, true);
1740 * Give a chance for the known devices to complete their probes, before
1741 * disable probing of devices. This sync point is important at least
1742 * at boot time + hibernation restore.
1744 wait_for_device_probe();
1746 * It is unsafe if probing of devices will happen during suspend or
1747 * hibernation and system behavior will be unpredictable in this case.
1748 * So, let's prohibit device's probing here and defer their probes
1749 * instead. The normal behavior will be restored in dpm_complete().
1751 device_block_probing();
1753 mutex_lock(&dpm_list_mtx
);
1754 while (!list_empty(&dpm_list
)) {
1755 struct device
*dev
= to_device(dpm_list
.next
);
1758 mutex_unlock(&dpm_list_mtx
);
1760 trace_device_pm_callback_start(dev
, "", state
.event
);
1761 error
= device_prepare(dev
, state
);
1762 trace_device_pm_callback_end(dev
, error
);
1764 mutex_lock(&dpm_list_mtx
);
1766 if (error
== -EAGAIN
) {
1771 printk(KERN_INFO
"PM: Device %s not prepared "
1772 "for power transition: code %d\n",
1773 dev_name(dev
), error
);
1777 dev
->power
.is_prepared
= true;
1778 if (!list_empty(&dev
->power
.entry
))
1779 list_move_tail(&dev
->power
.entry
, &dpm_prepared_list
);
1782 mutex_unlock(&dpm_list_mtx
);
1783 trace_suspend_resume(TPS("dpm_prepare"), state
.event
, false);
1788 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1789 * @state: PM transition of the system being carried out.
1791 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1792 * callbacks for them.
1794 int dpm_suspend_start(pm_message_t state
)
1798 error
= dpm_prepare(state
);
1800 suspend_stats
.failed_prepare
++;
1801 dpm_save_failed_step(SUSPEND_PREPARE
);
1803 error
= dpm_suspend(state
);
1806 EXPORT_SYMBOL_GPL(dpm_suspend_start
);
1808 void __suspend_report_result(const char *function
, void *fn
, int ret
)
1811 printk(KERN_ERR
"%s(): %pF returns %d\n", function
, fn
, ret
);
1813 EXPORT_SYMBOL_GPL(__suspend_report_result
);
1816 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1817 * @dev: Device to wait for.
1818 * @subordinate: Device that needs to wait for @dev.
1820 int device_pm_wait_for_dev(struct device
*subordinate
, struct device
*dev
)
1822 dpm_wait(dev
, subordinate
->power
.async_suspend
);
1825 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev
);
1828 * dpm_for_each_dev - device iterator.
1829 * @data: data for the callback.
1830 * @fn: function to be called for each device.
1832 * Iterate over devices in dpm_list, and call @fn for each device,
1835 void dpm_for_each_dev(void *data
, void (*fn
)(struct device
*, void *))
1843 list_for_each_entry(dev
, &dpm_list
, power
.entry
)
1847 EXPORT_SYMBOL_GPL(dpm_for_each_dev
);
1849 static bool pm_ops_is_empty(const struct dev_pm_ops
*ops
)
1854 return !ops
->prepare
&&
1856 !ops
->suspend_late
&&
1857 !ops
->suspend_noirq
&&
1858 !ops
->resume_noirq
&&
1859 !ops
->resume_early
&&
1864 void device_pm_check_callbacks(struct device
*dev
)
1866 spin_lock_irq(&dev
->power
.lock
);
1867 dev
->power
.no_pm_callbacks
=
1868 (!dev
->bus
|| (pm_ops_is_empty(dev
->bus
->pm
) &&
1869 !dev
->bus
->suspend
&& !dev
->bus
->resume
)) &&
1870 (!dev
->class || pm_ops_is_empty(dev
->class->pm
)) &&
1871 (!dev
->type
|| pm_ops_is_empty(dev
->type
->pm
)) &&
1872 (!dev
->pm_domain
|| pm_ops_is_empty(&dev
->pm_domain
->ops
)) &&
1873 (!dev
->driver
|| (pm_ops_is_empty(dev
->driver
->pm
) &&
1874 !dev
->driver
->suspend
&& !dev
->driver
->resume
));
1875 spin_unlock_irq(&dev
->power
.lock
);
1878 bool dev_pm_smart_suspend_and_suspended(struct device
*dev
)
1880 return dev_pm_test_driver_flags(dev
, DPM_FLAG_SMART_SUSPEND
) &&
1881 pm_runtime_status_suspended(dev
);