1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * kernel/power/suspend.c - Suspend to RAM and standby functionality. |
4 | * |
5 | * Copyright (c) 2003 Patrick Mochel |
6 | * Copyright (c) 2003 Open Source Development Lab |
7 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
8 | */ |
9 | |
10 | #define pr_fmt(fmt) "PM: " fmt |
11 | |
12 | #include <linux/string.h> |
13 | #include <linux/delay.h> |
14 | #include <linux/errno.h> |
15 | #include <linux/init.h> |
16 | #include <linux/console.h> |
17 | #include <linux/cpu.h> |
18 | #include <linux/cpuidle.h> |
19 | #include <linux/gfp.h> |
20 | #include <linux/io.h> |
21 | #include <linux/kernel.h> |
22 | #include <linux/list.h> |
23 | #include <linux/mm.h> |
24 | #include <linux/slab.h> |
25 | #include <linux/export.h> |
26 | #include <linux/suspend.h> |
27 | #include <linux/syscore_ops.h> |
28 | #include <linux/swait.h> |
29 | #include <linux/ftrace.h> |
30 | #include <trace/events/power.h> |
31 | #include <linux/compiler.h> |
32 | #include <linux/moduleparam.h> |
33 | |
34 | #include "power.h" |
35 | |
36 | const char * const pm_labels[] = { |
37 | [PM_SUSPEND_TO_IDLE] = "freeze" , |
38 | [PM_SUSPEND_STANDBY] = "standby" , |
39 | [PM_SUSPEND_MEM] = "mem" , |
40 | }; |
41 | const char *pm_states[PM_SUSPEND_MAX]; |
42 | static const char * const mem_sleep_labels[] = { |
43 | [PM_SUSPEND_TO_IDLE] = "s2idle" , |
44 | [PM_SUSPEND_STANDBY] = "shallow" , |
45 | [PM_SUSPEND_MEM] = "deep" , |
46 | }; |
47 | const char *mem_sleep_states[PM_SUSPEND_MAX]; |
48 | |
49 | suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE; |
50 | suspend_state_t mem_sleep_default = PM_SUSPEND_MAX; |
51 | suspend_state_t pm_suspend_target_state; |
52 | EXPORT_SYMBOL_GPL(pm_suspend_target_state); |
53 | |
54 | unsigned int pm_suspend_global_flags; |
55 | EXPORT_SYMBOL_GPL(pm_suspend_global_flags); |
56 | |
57 | static const struct platform_suspend_ops *suspend_ops; |
58 | static const struct platform_s2idle_ops *s2idle_ops; |
59 | static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head); |
60 | |
61 | enum s2idle_states __read_mostly s2idle_state; |
62 | static DEFINE_RAW_SPINLOCK(s2idle_lock); |
63 | |
64 | /** |
65 | * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend. |
66 | * |
67 | * Return 'true' if suspend-to-idle has been selected as the default system |
68 | * suspend method. |
69 | */ |
70 | bool pm_suspend_default_s2idle(void) |
71 | { |
72 | return mem_sleep_current == PM_SUSPEND_TO_IDLE; |
73 | } |
74 | EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle); |
75 | |
76 | void s2idle_set_ops(const struct platform_s2idle_ops *ops) |
77 | { |
78 | unsigned int sleep_flags; |
79 | |
80 | sleep_flags = lock_system_sleep(); |
81 | s2idle_ops = ops; |
82 | unlock_system_sleep(sleep_flags); |
83 | } |
84 | |
85 | static void s2idle_begin(void) |
86 | { |
87 | s2idle_state = S2IDLE_STATE_NONE; |
88 | } |
89 | |
90 | static void s2idle_enter(void) |
91 | { |
92 | trace_suspend_resume(TPS("machine_suspend" ), PM_SUSPEND_TO_IDLE, start: true); |
93 | |
94 | raw_spin_lock_irq(&s2idle_lock); |
95 | if (pm_wakeup_pending()) |
96 | goto out; |
97 | |
98 | s2idle_state = S2IDLE_STATE_ENTER; |
99 | raw_spin_unlock_irq(&s2idle_lock); |
100 | |
101 | cpus_read_lock(); |
102 | |
103 | /* Push all the CPUs into the idle loop. */ |
104 | wake_up_all_idle_cpus(); |
105 | /* Make the current CPU wait so it can enter the idle loop too. */ |
106 | swait_event_exclusive(s2idle_wait_head, |
107 | s2idle_state == S2IDLE_STATE_WAKE); |
108 | |
109 | /* |
110 | * Kick all CPUs to ensure that they resume their timers and restore |
111 | * consistent system state. |
112 | */ |
113 | wake_up_all_idle_cpus(); |
114 | |
115 | cpus_read_unlock(); |
116 | |
117 | raw_spin_lock_irq(&s2idle_lock); |
118 | |
119 | out: |
120 | s2idle_state = S2IDLE_STATE_NONE; |
121 | raw_spin_unlock_irq(&s2idle_lock); |
122 | |
123 | trace_suspend_resume(TPS("machine_suspend" ), PM_SUSPEND_TO_IDLE, start: false); |
124 | } |
125 | |
126 | static void s2idle_loop(void) |
127 | { |
128 | pm_pr_dbg("suspend-to-idle\n" ); |
129 | |
130 | /* |
131 | * Suspend-to-idle equals: |
132 | * frozen processes + suspended devices + idle processors. |
133 | * Thus s2idle_enter() should be called right after all devices have |
134 | * been suspended. |
135 | * |
136 | * Wakeups during the noirq suspend of devices may be spurious, so try |
137 | * to avoid them upfront. |
138 | */ |
139 | for (;;) { |
140 | if (s2idle_ops && s2idle_ops->wake) { |
141 | if (s2idle_ops->wake()) |
142 | break; |
143 | } else if (pm_wakeup_pending()) { |
144 | break; |
145 | } |
146 | |
147 | if (s2idle_ops && s2idle_ops->check) |
148 | s2idle_ops->check(); |
149 | |
150 | s2idle_enter(); |
151 | } |
152 | |
153 | pm_pr_dbg("resume from suspend-to-idle\n" ); |
154 | } |
155 | |
156 | void s2idle_wake(void) |
157 | { |
158 | unsigned long flags; |
159 | |
160 | raw_spin_lock_irqsave(&s2idle_lock, flags); |
161 | if (s2idle_state > S2IDLE_STATE_NONE) { |
162 | s2idle_state = S2IDLE_STATE_WAKE; |
163 | swake_up_one(q: &s2idle_wait_head); |
164 | } |
165 | raw_spin_unlock_irqrestore(&s2idle_lock, flags); |
166 | } |
167 | EXPORT_SYMBOL_GPL(s2idle_wake); |
168 | |
169 | static bool valid_state(suspend_state_t state) |
170 | { |
171 | /* |
172 | * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level |
173 | * support and need to be valid to the low-level implementation. |
174 | * |
175 | * No ->valid() or ->enter() callback implies that none are valid. |
176 | */ |
177 | return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) && |
178 | suspend_ops->enter; |
179 | } |
180 | |
181 | void __init pm_states_init(void) |
182 | { |
183 | /* "mem" and "freeze" are always present in /sys/power/state. */ |
184 | pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM]; |
185 | pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE]; |
186 | /* |
187 | * Suspend-to-idle should be supported even without any suspend_ops, |
188 | * initialize mem_sleep_states[] accordingly here. |
189 | */ |
190 | mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE]; |
191 | } |
192 | |
193 | static int __init mem_sleep_default_setup(char *str) |
194 | { |
195 | suspend_state_t state; |
196 | |
197 | for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++) |
198 | if (mem_sleep_labels[state] && |
199 | !strcmp(str, mem_sleep_labels[state])) { |
200 | mem_sleep_default = state; |
201 | mem_sleep_current = state; |
202 | break; |
203 | } |
204 | |
205 | return 1; |
206 | } |
207 | __setup("mem_sleep_default=" , mem_sleep_default_setup); |
208 | |
209 | /** |
210 | * suspend_set_ops - Set the global suspend method table. |
211 | * @ops: Suspend operations to use. |
212 | */ |
213 | void suspend_set_ops(const struct platform_suspend_ops *ops) |
214 | { |
215 | unsigned int sleep_flags; |
216 | |
217 | sleep_flags = lock_system_sleep(); |
218 | |
219 | suspend_ops = ops; |
220 | |
221 | if (valid_state(PM_SUSPEND_STANDBY)) { |
222 | mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY]; |
223 | pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY]; |
224 | if (mem_sleep_default == PM_SUSPEND_STANDBY) |
225 | mem_sleep_current = PM_SUSPEND_STANDBY; |
226 | } |
227 | if (valid_state(PM_SUSPEND_MEM)) { |
228 | mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM]; |
229 | if (mem_sleep_default >= PM_SUSPEND_MEM) |
230 | mem_sleep_current = PM_SUSPEND_MEM; |
231 | } |
232 | |
233 | unlock_system_sleep(sleep_flags); |
234 | } |
235 | EXPORT_SYMBOL_GPL(suspend_set_ops); |
236 | |
237 | /** |
238 | * suspend_valid_only_mem - Generic memory-only valid callback. |
239 | * @state: Target system sleep state. |
240 | * |
241 | * Platform drivers that implement mem suspend only and only need to check for |
242 | * that in their .valid() callback can use this instead of rolling their own |
243 | * .valid() callback. |
244 | */ |
245 | int suspend_valid_only_mem(suspend_state_t state) |
246 | { |
247 | return state == PM_SUSPEND_MEM; |
248 | } |
249 | EXPORT_SYMBOL_GPL(suspend_valid_only_mem); |
250 | |
251 | static bool sleep_state_supported(suspend_state_t state) |
252 | { |
253 | return state == PM_SUSPEND_TO_IDLE || |
254 | (valid_state(state) && !cxl_mem_active()); |
255 | } |
256 | |
257 | static int platform_suspend_prepare(suspend_state_t state) |
258 | { |
259 | return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ? |
260 | suspend_ops->prepare() : 0; |
261 | } |
262 | |
263 | static int platform_suspend_prepare_late(suspend_state_t state) |
264 | { |
265 | return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ? |
266 | s2idle_ops->prepare() : 0; |
267 | } |
268 | |
269 | static int platform_suspend_prepare_noirq(suspend_state_t state) |
270 | { |
271 | if (state == PM_SUSPEND_TO_IDLE) |
272 | return s2idle_ops && s2idle_ops->prepare_late ? |
273 | s2idle_ops->prepare_late() : 0; |
274 | |
275 | return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0; |
276 | } |
277 | |
278 | static void platform_resume_noirq(suspend_state_t state) |
279 | { |
280 | if (state == PM_SUSPEND_TO_IDLE) { |
281 | if (s2idle_ops && s2idle_ops->restore_early) |
282 | s2idle_ops->restore_early(); |
283 | } else if (suspend_ops->wake) { |
284 | suspend_ops->wake(); |
285 | } |
286 | } |
287 | |
288 | static void platform_resume_early(suspend_state_t state) |
289 | { |
290 | if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore) |
291 | s2idle_ops->restore(); |
292 | } |
293 | |
294 | static void platform_resume_finish(suspend_state_t state) |
295 | { |
296 | if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish) |
297 | suspend_ops->finish(); |
298 | } |
299 | |
300 | static int platform_suspend_begin(suspend_state_t state) |
301 | { |
302 | if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin) |
303 | return s2idle_ops->begin(); |
304 | else if (suspend_ops && suspend_ops->begin) |
305 | return suspend_ops->begin(state); |
306 | else |
307 | return 0; |
308 | } |
309 | |
310 | static void platform_resume_end(suspend_state_t state) |
311 | { |
312 | if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end) |
313 | s2idle_ops->end(); |
314 | else if (suspend_ops && suspend_ops->end) |
315 | suspend_ops->end(); |
316 | } |
317 | |
318 | static void platform_recover(suspend_state_t state) |
319 | { |
320 | if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover) |
321 | suspend_ops->recover(); |
322 | } |
323 | |
324 | static bool platform_suspend_again(suspend_state_t state) |
325 | { |
326 | return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ? |
327 | suspend_ops->suspend_again() : false; |
328 | } |
329 | |
330 | #ifdef CONFIG_PM_DEBUG |
331 | static unsigned int pm_test_delay = 5; |
332 | module_param(pm_test_delay, uint, 0644); |
333 | MODULE_PARM_DESC(pm_test_delay, |
334 | "Number of seconds to wait before resuming from suspend test" ); |
335 | #endif |
336 | |
337 | static int suspend_test(int level) |
338 | { |
339 | #ifdef CONFIG_PM_DEBUG |
340 | if (pm_test_level == level) { |
341 | pr_info("suspend debug: Waiting for %d second(s).\n" , |
342 | pm_test_delay); |
343 | mdelay(pm_test_delay * 1000); |
344 | return 1; |
345 | } |
346 | #endif /* !CONFIG_PM_DEBUG */ |
347 | return 0; |
348 | } |
349 | |
350 | /** |
351 | * suspend_prepare - Prepare for entering system sleep state. |
352 | * @state: Target system sleep state. |
353 | * |
354 | * Common code run for every system sleep state that can be entered (except for |
355 | * hibernation). Run suspend notifiers, allocate the "suspend" console and |
356 | * freeze processes. |
357 | */ |
358 | static int suspend_prepare(suspend_state_t state) |
359 | { |
360 | int error; |
361 | |
362 | if (!sleep_state_supported(state)) |
363 | return -EPERM; |
364 | |
365 | pm_prepare_console(); |
366 | |
367 | error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND); |
368 | if (error) |
369 | goto Restore; |
370 | |
371 | trace_suspend_resume(TPS("freeze_processes" ), val: 0, start: true); |
372 | error = suspend_freeze_processes(); |
373 | trace_suspend_resume(TPS("freeze_processes" ), val: 0, start: false); |
374 | if (!error) |
375 | return 0; |
376 | |
377 | dpm_save_failed_step(step: SUSPEND_FREEZE); |
378 | pm_notifier_call_chain(PM_POST_SUSPEND); |
379 | Restore: |
380 | pm_restore_console(); |
381 | return error; |
382 | } |
383 | |
384 | /* default implementation */ |
385 | void __weak arch_suspend_disable_irqs(void) |
386 | { |
387 | local_irq_disable(); |
388 | } |
389 | |
390 | /* default implementation */ |
391 | void __weak arch_suspend_enable_irqs(void) |
392 | { |
393 | local_irq_enable(); |
394 | } |
395 | |
396 | /** |
397 | * suspend_enter - Make the system enter the given sleep state. |
398 | * @state: System sleep state to enter. |
399 | * @wakeup: Returns information that the sleep state should not be re-entered. |
400 | * |
401 | * This function should be called after devices have been suspended. |
402 | */ |
403 | static int suspend_enter(suspend_state_t state, bool *wakeup) |
404 | { |
405 | int error; |
406 | |
407 | error = platform_suspend_prepare(state); |
408 | if (error) |
409 | goto Platform_finish; |
410 | |
411 | error = dpm_suspend_late(PMSG_SUSPEND); |
412 | if (error) { |
413 | pr_err("late suspend of devices failed\n" ); |
414 | goto Platform_finish; |
415 | } |
416 | error = platform_suspend_prepare_late(state); |
417 | if (error) |
418 | goto Devices_early_resume; |
419 | |
420 | error = dpm_suspend_noirq(PMSG_SUSPEND); |
421 | if (error) { |
422 | pr_err("noirq suspend of devices failed\n" ); |
423 | goto Platform_early_resume; |
424 | } |
425 | error = platform_suspend_prepare_noirq(state); |
426 | if (error) |
427 | goto Platform_wake; |
428 | |
429 | if (suspend_test(level: TEST_PLATFORM)) |
430 | goto Platform_wake; |
431 | |
432 | if (state == PM_SUSPEND_TO_IDLE) { |
433 | s2idle_loop(); |
434 | goto Platform_wake; |
435 | } |
436 | |
437 | error = pm_sleep_disable_secondary_cpus(); |
438 | if (error || suspend_test(level: TEST_CPUS)) |
439 | goto Enable_cpus; |
440 | |
441 | arch_suspend_disable_irqs(); |
442 | BUG_ON(!irqs_disabled()); |
443 | |
444 | system_state = SYSTEM_SUSPEND; |
445 | |
446 | error = syscore_suspend(); |
447 | if (!error) { |
448 | *wakeup = pm_wakeup_pending(); |
449 | if (!(suspend_test(level: TEST_CORE) || *wakeup)) { |
450 | trace_suspend_resume(TPS("machine_suspend" ), |
451 | val: state, start: true); |
452 | error = suspend_ops->enter(state); |
453 | trace_suspend_resume(TPS("machine_suspend" ), |
454 | val: state, start: false); |
455 | } else if (*wakeup) { |
456 | error = -EBUSY; |
457 | } |
458 | syscore_resume(); |
459 | } |
460 | |
461 | system_state = SYSTEM_RUNNING; |
462 | |
463 | arch_suspend_enable_irqs(); |
464 | BUG_ON(irqs_disabled()); |
465 | |
466 | Enable_cpus: |
467 | pm_sleep_enable_secondary_cpus(); |
468 | |
469 | Platform_wake: |
470 | platform_resume_noirq(state); |
471 | dpm_resume_noirq(PMSG_RESUME); |
472 | |
473 | Platform_early_resume: |
474 | platform_resume_early(state); |
475 | |
476 | Devices_early_resume: |
477 | dpm_resume_early(PMSG_RESUME); |
478 | |
479 | Platform_finish: |
480 | platform_resume_finish(state); |
481 | return error; |
482 | } |
483 | |
484 | /** |
485 | * suspend_devices_and_enter - Suspend devices and enter system sleep state. |
486 | * @state: System sleep state to enter. |
487 | */ |
488 | int suspend_devices_and_enter(suspend_state_t state) |
489 | { |
490 | int error; |
491 | bool wakeup = false; |
492 | |
493 | if (!sleep_state_supported(state)) |
494 | return -ENOSYS; |
495 | |
496 | pm_suspend_target_state = state; |
497 | |
498 | if (state == PM_SUSPEND_TO_IDLE) |
499 | pm_set_suspend_no_platform(); |
500 | |
501 | error = platform_suspend_begin(state); |
502 | if (error) |
503 | goto Close; |
504 | |
505 | suspend_console(); |
506 | suspend_test_start(); |
507 | error = dpm_suspend_start(PMSG_SUSPEND); |
508 | if (error) { |
509 | pr_err("Some devices failed to suspend, or early wake event detected\n" ); |
510 | goto Recover_platform; |
511 | } |
512 | suspend_test_finish(label: "suspend devices" ); |
513 | if (suspend_test(level: TEST_DEVICES)) |
514 | goto Recover_platform; |
515 | |
516 | do { |
517 | error = suspend_enter(state, wakeup: &wakeup); |
518 | } while (!error && !wakeup && platform_suspend_again(state)); |
519 | |
520 | Resume_devices: |
521 | suspend_test_start(); |
522 | dpm_resume_end(PMSG_RESUME); |
523 | suspend_test_finish(label: "resume devices" ); |
524 | trace_suspend_resume(TPS("resume_console" ), val: state, start: true); |
525 | resume_console(); |
526 | trace_suspend_resume(TPS("resume_console" ), val: state, start: false); |
527 | |
528 | Close: |
529 | platform_resume_end(state); |
530 | pm_suspend_target_state = PM_SUSPEND_ON; |
531 | return error; |
532 | |
533 | Recover_platform: |
534 | platform_recover(state); |
535 | goto Resume_devices; |
536 | } |
537 | |
538 | /** |
539 | * suspend_finish - Clean up before finishing the suspend sequence. |
540 | * |
541 | * Call platform code to clean up, restart processes, and free the console that |
542 | * we've allocated. This routine is not called for hibernation. |
543 | */ |
544 | static void suspend_finish(void) |
545 | { |
546 | suspend_thaw_processes(); |
547 | pm_notifier_call_chain(PM_POST_SUSPEND); |
548 | pm_restore_console(); |
549 | } |
550 | |
551 | /** |
552 | * enter_state - Do common work needed to enter system sleep state. |
553 | * @state: System sleep state to enter. |
554 | * |
555 | * Make sure that no one else is trying to put the system into a sleep state. |
556 | * Fail if that's not the case. Otherwise, prepare for system suspend, make the |
557 | * system enter the given sleep state and clean up after wakeup. |
558 | */ |
559 | static int enter_state(suspend_state_t state) |
560 | { |
561 | int error; |
562 | |
563 | trace_suspend_resume(TPS("suspend_enter" ), val: state, start: true); |
564 | if (state == PM_SUSPEND_TO_IDLE) { |
565 | #ifdef CONFIG_PM_DEBUG |
566 | if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { |
567 | pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n" ); |
568 | return -EAGAIN; |
569 | } |
570 | #endif |
571 | } else if (!valid_state(state)) { |
572 | return -EINVAL; |
573 | } |
574 | if (!mutex_trylock(lock: &system_transition_mutex)) |
575 | return -EBUSY; |
576 | |
577 | if (state == PM_SUSPEND_TO_IDLE) |
578 | s2idle_begin(); |
579 | |
580 | if (sync_on_suspend_enabled) { |
581 | trace_suspend_resume(TPS("sync_filesystems" ), val: 0, start: true); |
582 | ksys_sync_helper(); |
583 | trace_suspend_resume(TPS("sync_filesystems" ), val: 0, start: false); |
584 | } |
585 | |
586 | pm_pr_dbg("Preparing system for sleep (%s)\n" , mem_sleep_labels[state]); |
587 | pm_suspend_clear_flags(); |
588 | error = suspend_prepare(state); |
589 | if (error) |
590 | goto Unlock; |
591 | |
592 | if (suspend_test(level: TEST_FREEZER)) |
593 | goto Finish; |
594 | |
595 | trace_suspend_resume(TPS("suspend_enter" ), val: state, start: false); |
596 | pm_pr_dbg("Suspending system (%s)\n" , mem_sleep_labels[state]); |
597 | pm_restrict_gfp_mask(); |
598 | error = suspend_devices_and_enter(state); |
599 | pm_restore_gfp_mask(); |
600 | |
601 | Finish: |
602 | events_check_enabled = false; |
603 | pm_pr_dbg("Finishing wakeup.\n" ); |
604 | suspend_finish(); |
605 | Unlock: |
606 | mutex_unlock(lock: &system_transition_mutex); |
607 | return error; |
608 | } |
609 | |
610 | /** |
611 | * pm_suspend - Externally visible function for suspending the system. |
612 | * @state: System sleep state to enter. |
613 | * |
614 | * Check if the value of @state represents one of the supported states, |
615 | * execute enter_state() and update system suspend statistics. |
616 | */ |
617 | int pm_suspend(suspend_state_t state) |
618 | { |
619 | int error; |
620 | |
621 | if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX) |
622 | return -EINVAL; |
623 | |
624 | pr_info("suspend entry (%s)\n" , mem_sleep_labels[state]); |
625 | error = enter_state(state); |
626 | dpm_save_errno(err: error); |
627 | pr_info("suspend exit\n" ); |
628 | return error; |
629 | } |
630 | EXPORT_SYMBOL(pm_suspend); |
631 | |