1/*
   2 * drivers/base/power/main.c - Where the driver meets power management.
   3 *
   4 * Copyright (c) 2003 Patrick Mochel
   5 * Copyright (c) 2003 Open Source Development Lab
   6 *
   7 * This file is released under the GPLv2
   8 *
   9 *
  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.
  14 *
  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.
  18 */
  19
  20#include <linux/device.h>
  21#include <linux/kallsyms.h>
  22#include <linux/export.h>
  23#include <linux/mutex.h>
  24#include <linux/pm.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/async.h>
  31#include <linux/suspend.h>
  32#include <trace/events/power.h>
  33#include <linux/cpufreq.h>
  34#include <linux/cpuidle.h>
  35#include <linux/timer.h>
  36
  37#include "../base.h"
  38#include "power.h"
  39
  40typedef int (*pm_callback_t)(struct device *);
  41
  42/*
  43 * The entries in the dpm_list list are in a depth first order, simply
  44 * because children are guaranteed to be discovered after parents, and
  45 * are inserted at the back of the list on discovery.
  46 *
  47 * Since device_pm_add() may be called with a device lock held,
  48 * we must never try to acquire a device lock while holding
  49 * dpm_list_mutex.
  50 */
  51
  52LIST_HEAD(dpm_list);
  53static LIST_HEAD(dpm_prepared_list);
  54static LIST_HEAD(dpm_suspended_list);
  55static LIST_HEAD(dpm_late_early_list);
  56static LIST_HEAD(dpm_noirq_list);
  57
  58struct suspend_stats suspend_stats;
  59static DEFINE_MUTEX(dpm_list_mtx);
  60static pm_message_t pm_transition;
  61
  62static int async_error;
  63
  64static char *pm_verb(int event)
  65{
  66	switch (event) {
  67	case PM_EVENT_SUSPEND:
  68		return "suspend";
  69	case PM_EVENT_RESUME:
  70		return "resume";
  71	case PM_EVENT_FREEZE:
  72		return "freeze";
  73	case PM_EVENT_QUIESCE:
  74		return "quiesce";
  75	case PM_EVENT_HIBERNATE:
  76		return "hibernate";
  77	case PM_EVENT_THAW:
  78		return "thaw";
  79	case PM_EVENT_RESTORE:
  80		return "restore";
  81	case PM_EVENT_RECOVER:
  82		return "recover";
  83	default:
  84		return "(unknown PM event)";
  85	}
  86}
  87
  88/**
  89 * device_pm_sleep_init - Initialize system suspend-related device fields.
  90 * @dev: Device object being initialized.
  91 */
  92void device_pm_sleep_init(struct device *dev)
  93{
  94	dev->power.is_prepared = false;
  95	dev->power.is_suspended = false;
  96	dev->power.is_noirq_suspended = false;
  97	dev->power.is_late_suspended = false;
  98	init_completion(&dev->power.completion);
  99	complete_all(&dev->power.completion);
 100	dev->power.wakeup = NULL;
 101	INIT_LIST_HEAD(&dev->power.entry);
 102}
 103
 104/**
 105 * device_pm_lock - Lock the list of active devices used by the PM core.
 106 */
 107void device_pm_lock(void)
 108{
 109	mutex_lock(&dpm_list_mtx);
 110}
 111
 112/**
 113 * device_pm_unlock - Unlock the list of active devices used by the PM core.
 114 */
 115void device_pm_unlock(void)
 116{
 117	mutex_unlock(&dpm_list_mtx);
 118}
 119
 120/**
 121 * device_pm_add - Add a device to the PM core's list of active devices.
 122 * @dev: Device to add to the list.
 123 */
 124void device_pm_add(struct device *dev)
 125{
 126	pr_debug("PM: Adding info for %s:%s\n",
 127		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 128	device_pm_check_callbacks(dev);
 129	mutex_lock(&dpm_list_mtx);
 130	if (dev->parent && dev->parent->power.is_prepared)
 131		dev_warn(dev, "parent %s should not be sleeping\n",
 132			dev_name(dev->parent));
 133	list_add_tail(&dev->power.entry, &dpm_list);
 134	mutex_unlock(&dpm_list_mtx);
 135}
 136
 137/**
 138 * device_pm_remove - Remove a device from the PM core's list of active devices.
 139 * @dev: Device to be removed from the list.
 140 */
 141void device_pm_remove(struct device *dev)
 142{
 143	pr_debug("PM: Removing info for %s:%s\n",
 144		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 145	complete_all(&dev->power.completion);
 146	mutex_lock(&dpm_list_mtx);
 147	list_del_init(&dev->power.entry);
 148	mutex_unlock(&dpm_list_mtx);
 149	device_wakeup_disable(dev);
 150	pm_runtime_remove(dev);
 151	device_pm_check_callbacks(dev);
 152}
 153
 154/**
 155 * device_pm_move_before - Move device in the PM core's list of active devices.
 156 * @deva: Device to move in dpm_list.
 157 * @devb: Device @deva should come before.
 158 */
 159void device_pm_move_before(struct device *deva, struct device *devb)
 160{
 161	pr_debug("PM: Moving %s:%s before %s:%s\n",
 162		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 163		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 164	/* Delete deva from dpm_list and reinsert before devb. */
 165	list_move_tail(&deva->power.entry, &devb->power.entry);
 166}
 167
 168/**
 169 * device_pm_move_after - Move device in the PM core's list of active devices.
 170 * @deva: Device to move in dpm_list.
 171 * @devb: Device @deva should come after.
 172 */
 173void device_pm_move_after(struct device *deva, struct device *devb)
 174{
 175	pr_debug("PM: Moving %s:%s after %s:%s\n",
 176		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 177		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 178	/* Delete deva from dpm_list and reinsert after devb. */
 179	list_move(&deva->power.entry, &devb->power.entry);
 180}
 181
 182/**
 183 * device_pm_move_last - Move device to end of the PM core's list of devices.
 184 * @dev: Device to move in dpm_list.
 185 */
 186void device_pm_move_last(struct device *dev)
 187{
 188	pr_debug("PM: Moving %s:%s to end of list\n",
 189		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 190	list_move_tail(&dev->power.entry, &dpm_list);
 191}
 192
 193static ktime_t initcall_debug_start(struct device *dev)
 194{
 195	ktime_t calltime = ktime_set(0, 0);
 196
 197	if (pm_print_times_enabled) {
 198		pr_info("calling  %s+ @ %i, parent: %s\n",
 199			dev_name(dev), task_pid_nr(current),
 200			dev->parent ? dev_name(dev->parent) : "none");
 201		calltime = ktime_get();
 202	}
 203
 204	return calltime;
 205}
 206
 207static void initcall_debug_report(struct device *dev, ktime_t calltime,
 208				  int error, pm_message_t state, char *info)
 209{
 210	ktime_t rettime;
 211	s64 nsecs;
 212
 213	rettime = ktime_get();
 214	nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 215
 216	if (pm_print_times_enabled) {
 217		pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 218			error, (unsigned long long)nsecs >> 10);
 219	}
 
 
 
 220}
 221
 222/**
 223 * dpm_wait - Wait for a PM operation to complete.
 224 * @dev: Device to wait for.
 225 * @async: If unset, wait only if the device's power.async_suspend flag is set.
 226 */
 227static void dpm_wait(struct device *dev, bool async)
 228{
 229	if (!dev)
 230		return;
 231
 232	if (async || (pm_async_enabled && dev->power.async_suspend))
 233		wait_for_completion(&dev->power.completion);
 234}
 235
 236static int dpm_wait_fn(struct device *dev, void *async_ptr)
 237{
 238	dpm_wait(dev, *((bool *)async_ptr));
 239	return 0;
 240}
 241
 242static void dpm_wait_for_children(struct device *dev, bool async)
 243{
 244       device_for_each_child(dev, &async, dpm_wait_fn);
 245}
 246
 247/**
 248 * pm_op - Return the PM operation appropriate for given PM event.
 249 * @ops: PM operations to choose from.
 250 * @state: PM transition of the system being carried out.
 251 */
 252static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 253{
 254	switch (state.event) {
 255#ifdef CONFIG_SUSPEND
 256	case PM_EVENT_SUSPEND:
 257		return ops->suspend;
 258	case PM_EVENT_RESUME:
 259		return ops->resume;
 260#endif /* CONFIG_SUSPEND */
 261#ifdef CONFIG_HIBERNATE_CALLBACKS
 262	case PM_EVENT_FREEZE:
 263	case PM_EVENT_QUIESCE:
 264		return ops->freeze;
 265	case PM_EVENT_HIBERNATE:
 266		return ops->poweroff;
 267	case PM_EVENT_THAW:
 268	case PM_EVENT_RECOVER:
 269		return ops->thaw;
 270		break;
 271	case PM_EVENT_RESTORE:
 272		return ops->restore;
 273#endif /* CONFIG_HIBERNATE_CALLBACKS */
 274	}
 275
 276	return NULL;
 277}
 278
 279/**
 280 * pm_late_early_op - Return the PM operation appropriate for given PM event.
 281 * @ops: PM operations to choose from.
 282 * @state: PM transition of the system being carried out.
 283 *
 284 * Runtime PM is disabled for @dev while this function is being executed.
 285 */
 286static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 287				      pm_message_t state)
 288{
 289	switch (state.event) {
 290#ifdef CONFIG_SUSPEND
 291	case PM_EVENT_SUSPEND:
 292		return ops->suspend_late;
 293	case PM_EVENT_RESUME:
 294		return ops->resume_early;
 295#endif /* CONFIG_SUSPEND */
 296#ifdef CONFIG_HIBERNATE_CALLBACKS
 297	case PM_EVENT_FREEZE:
 298	case PM_EVENT_QUIESCE:
 299		return ops->freeze_late;
 300	case PM_EVENT_HIBERNATE:
 301		return ops->poweroff_late;
 302	case PM_EVENT_THAW:
 303	case PM_EVENT_RECOVER:
 304		return ops->thaw_early;
 305	case PM_EVENT_RESTORE:
 306		return ops->restore_early;
 307#endif /* CONFIG_HIBERNATE_CALLBACKS */
 308	}
 309
 310	return NULL;
 311}
 312
 313/**
 314 * pm_noirq_op - Return the PM operation appropriate for given PM event.
 315 * @ops: PM operations to choose from.
 316 * @state: PM transition of the system being carried out.
 317 *
 318 * The driver of @dev will not receive interrupts while this function is being
 319 * executed.
 320 */
 321static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 322{
 323	switch (state.event) {
 324#ifdef CONFIG_SUSPEND
 325	case PM_EVENT_SUSPEND:
 326		return ops->suspend_noirq;
 327	case PM_EVENT_RESUME:
 328		return ops->resume_noirq;
 329#endif /* CONFIG_SUSPEND */
 330#ifdef CONFIG_HIBERNATE_CALLBACKS
 331	case PM_EVENT_FREEZE:
 332	case PM_EVENT_QUIESCE:
 333		return ops->freeze_noirq;
 334	case PM_EVENT_HIBERNATE:
 335		return ops->poweroff_noirq;
 336	case PM_EVENT_THAW:
 337	case PM_EVENT_RECOVER:
 338		return ops->thaw_noirq;
 339	case PM_EVENT_RESTORE:
 340		return ops->restore_noirq;
 341#endif /* CONFIG_HIBERNATE_CALLBACKS */
 342	}
 343
 344	return NULL;
 345}
 346
 347static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 348{
 349	dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 350		((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 351		", may wakeup" : "");
 352}
 353
 354static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 355			int error)
 356{
 357	printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 358		dev_name(dev), pm_verb(state.event), info, error);
 359}
 360
 361static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 362{
 363	ktime_t calltime;
 364	u64 usecs64;
 365	int usecs;
 366
 367	calltime = ktime_get();
 368	usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 369	do_div(usecs64, NSEC_PER_USEC);
 370	usecs = usecs64;
 371	if (usecs == 0)
 372		usecs = 1;
 373	pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 374		info ?: "", info ? " " : "", pm_verb(state.event),
 375		usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 376}
 377
 378static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 379			    pm_message_t state, char *info)
 380{
 381	ktime_t calltime;
 382	int error;
 383
 384	if (!cb)
 385		return 0;
 386
 387	calltime = initcall_debug_start(dev);
 388
 389	pm_dev_dbg(dev, state, info);
 390	trace_device_pm_callback_start(dev, info, state.event);
 391	error = cb(dev);
 392	trace_device_pm_callback_end(dev, error);
 393	suspend_report_result(cb, error);
 394
 395	initcall_debug_report(dev, calltime, error, state, info);
 396
 397	return error;
 398}
 399
 400#ifdef CONFIG_DPM_WATCHDOG
 401struct dpm_watchdog {
 402	struct device		*dev;
 403	struct task_struct	*tsk;
 404	struct timer_list	timer;
 405};
 406
 407#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 408	struct dpm_watchdog wd
 409
 410/**
 411 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 412 * @data: Watchdog object address.
 413 *
 414 * Called when a driver has timed out suspending or resuming.
 415 * There's not much we can do here to recover so panic() to
 416 * capture a crash-dump in pstore.
 417 */
 418static void dpm_watchdog_handler(unsigned long data)
 419{
 420	struct dpm_watchdog *wd = (void *)data;
 421
 422	dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 423	show_stack(wd->tsk, NULL);
 424	panic("%s %s: unrecoverable failure\n",
 425		dev_driver_string(wd->dev), dev_name(wd->dev));
 426}
 427
 428/**
 429 * dpm_watchdog_set - Enable pm watchdog for given device.
 430 * @wd: Watchdog. Must be allocated on the stack.
 431 * @dev: Device to handle.
 432 */
 433static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 434{
 435	struct timer_list *timer = &wd->timer;
 436
 437	wd->dev = dev;
 438	wd->tsk = current;
 439
 440	init_timer_on_stack(timer);
 441	/* use same timeout value for both suspend and resume */
 442	timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 443	timer->function = dpm_watchdog_handler;
 444	timer->data = (unsigned long)wd;
 445	add_timer(timer);
 446}
 447
 448/**
 449 * dpm_watchdog_clear - Disable suspend/resume watchdog.
 450 * @wd: Watchdog to disable.
 451 */
 452static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 453{
 454	struct timer_list *timer = &wd->timer;
 455
 456	del_timer_sync(timer);
 457	destroy_timer_on_stack(timer);
 458}
 459#else
 460#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 461#define dpm_watchdog_set(x, y)
 462#define dpm_watchdog_clear(x)
 463#endif
 464
 465/*------------------------- Resume routines -------------------------*/
 466
 467/**
 468 * device_resume_noirq - Execute an "early resume" callback for given device.
 469 * @dev: Device to handle.
 470 * @state: PM transition of the system being carried out.
 471 * @async: If true, the device is being resumed asynchronously.
 472 *
 473 * The driver of @dev will not receive interrupts while this function is being
 474 * executed.
 475 */
 476static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 477{
 478	pm_callback_t callback = NULL;
 479	char *info = NULL;
 480	int error = 0;
 481
 482	TRACE_DEVICE(dev);
 483	TRACE_RESUME(0);
 484
 485	if (dev->power.syscore || dev->power.direct_complete)
 486		goto Out;
 487
 488	if (!dev->power.is_noirq_suspended)
 489		goto Out;
 490
 491	dpm_wait(dev->parent, async);
 492
 493	if (dev->pm_domain) {
 494		info = "noirq power domain ";
 495		callback = pm_noirq_op(&dev->pm_domain->ops, state);
 496	} else if (dev->type && dev->type->pm) {
 497		info = "noirq type ";
 498		callback = pm_noirq_op(dev->type->pm, state);
 499	} else if (dev->class && dev->class->pm) {
 500		info = "noirq class ";
 501		callback = pm_noirq_op(dev->class->pm, state);
 502	} else if (dev->bus && dev->bus->pm) {
 503		info = "noirq bus ";
 504		callback = pm_noirq_op(dev->bus->pm, state);
 505	}
 506
 507	if (!callback && dev->driver && dev->driver->pm) {
 508		info = "noirq driver ";
 509		callback = pm_noirq_op(dev->driver->pm, state);
 510	}
 511
 512	error = dpm_run_callback(callback, dev, state, info);
 513	dev->power.is_noirq_suspended = false;
 514
 515 Out:
 516	complete_all(&dev->power.completion);
 517	TRACE_RESUME(error);
 518	return error;
 519}
 520
 521static bool is_async(struct device *dev)
 522{
 523	return dev->power.async_suspend && pm_async_enabled
 524		&& !pm_trace_is_enabled();
 525}
 526
 527static void async_resume_noirq(void *data, async_cookie_t cookie)
 528{
 529	struct device *dev = (struct device *)data;
 530	int error;
 531
 532	error = device_resume_noirq(dev, pm_transition, true);
 533	if (error)
 534		pm_dev_err(dev, pm_transition, " async", error);
 535
 536	put_device(dev);
 537}
 538
 539/**
 540 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 541 * @state: PM transition of the system being carried out.
 542 *
 543 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
 544 * enable device drivers to receive interrupts.
 545 */
 546void dpm_resume_noirq(pm_message_t state)
 547{
 548	struct device *dev;
 549	ktime_t starttime = ktime_get();
 550
 551	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 552	mutex_lock(&dpm_list_mtx);
 553	pm_transition = state;
 554
 555	/*
 556	 * Advanced the async threads upfront,
 557	 * in case the starting of async threads is
 558	 * delayed by non-async resuming devices.
 559	 */
 560	list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
 561		reinit_completion(&dev->power.completion);
 562		if (is_async(dev)) {
 563			get_device(dev);
 564			async_schedule(async_resume_noirq, dev);
 565		}
 566	}
 567
 568	while (!list_empty(&dpm_noirq_list)) {
 569		dev = to_device(dpm_noirq_list.next);
 570		get_device(dev);
 571		list_move_tail(&dev->power.entry, &dpm_late_early_list);
 572		mutex_unlock(&dpm_list_mtx);
 573
 574		if (!is_async(dev)) {
 575			int error;
 576
 577			error = device_resume_noirq(dev, state, false);
 578			if (error) {
 579				suspend_stats.failed_resume_noirq++;
 580				dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 581				dpm_save_failed_dev(dev_name(dev));
 582				pm_dev_err(dev, state, " noirq", error);
 583			}
 584		}
 585
 586		mutex_lock(&dpm_list_mtx);
 587		put_device(dev);
 588	}
 589	mutex_unlock(&dpm_list_mtx);
 590	async_synchronize_full();
 591	dpm_show_time(starttime, state, "noirq");
 592	resume_device_irqs();
 593	device_wakeup_disarm_wake_irqs();
 594	cpuidle_resume();
 595	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 596}
 597
 598/**
 599 * device_resume_early - Execute an "early resume" callback for given device.
 600 * @dev: Device to handle.
 601 * @state: PM transition of the system being carried out.
 602 * @async: If true, the device is being resumed asynchronously.
 603 *
 604 * Runtime PM is disabled for @dev while this function is being executed.
 605 */
 606static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 607{
 608	pm_callback_t callback = NULL;
 609	char *info = NULL;
 610	int error = 0;
 611
 612	TRACE_DEVICE(dev);
 613	TRACE_RESUME(0);
 614
 615	if (dev->power.syscore || dev->power.direct_complete)
 616		goto Out;
 617
 618	if (!dev->power.is_late_suspended)
 619		goto Out;
 620
 621	dpm_wait(dev->parent, async);
 622
 623	if (dev->pm_domain) {
 624		info = "early power domain ";
 625		callback = pm_late_early_op(&dev->pm_domain->ops, state);
 626	} else if (dev->type && dev->type->pm) {
 627		info = "early type ";
 628		callback = pm_late_early_op(dev->type->pm, state);
 629	} else if (dev->class && dev->class->pm) {
 630		info = "early class ";
 631		callback = pm_late_early_op(dev->class->pm, state);
 632	} else if (dev->bus && dev->bus->pm) {
 633		info = "early bus ";
 634		callback = pm_late_early_op(dev->bus->pm, state);
 635	}
 636
 637	if (!callback && dev->driver && dev->driver->pm) {
 638		info = "early driver ";
 639		callback = pm_late_early_op(dev->driver->pm, state);
 640	}
 641
 642	error = dpm_run_callback(callback, dev, state, info);
 643	dev->power.is_late_suspended = false;
 644
 645 Out:
 646	TRACE_RESUME(error);
 647
 648	pm_runtime_enable(dev);
 649	complete_all(&dev->power.completion);
 650	return error;
 651}
 652
 653static void async_resume_early(void *data, async_cookie_t cookie)
 654{
 655	struct device *dev = (struct device *)data;
 656	int error;
 657
 658	error = device_resume_early(dev, pm_transition, true);
 659	if (error)
 660		pm_dev_err(dev, pm_transition, " async", error);
 661
 662	put_device(dev);
 663}
 664
 665/**
 666 * dpm_resume_early - Execute "early resume" callbacks for all devices.
 667 * @state: PM transition of the system being carried out.
 668 */
 669void dpm_resume_early(pm_message_t state)
 670{
 671	struct device *dev;
 672	ktime_t starttime = ktime_get();
 673
 674	trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 675	mutex_lock(&dpm_list_mtx);
 676	pm_transition = state;
 677
 678	/*
 679	 * Advanced the async threads upfront,
 680	 * in case the starting of async threads is
 681	 * delayed by non-async resuming devices.
 682	 */
 683	list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
 684		reinit_completion(&dev->power.completion);
 685		if (is_async(dev)) {
 686			get_device(dev);
 687			async_schedule(async_resume_early, dev);
 688		}
 689	}
 690
 691	while (!list_empty(&dpm_late_early_list)) {
 692		dev = to_device(dpm_late_early_list.next);
 693		get_device(dev);
 694		list_move_tail(&dev->power.entry, &dpm_suspended_list);
 695		mutex_unlock(&dpm_list_mtx);
 696
 697		if (!is_async(dev)) {
 698			int error;
 699
 700			error = device_resume_early(dev, state, false);
 701			if (error) {
 702				suspend_stats.failed_resume_early++;
 703				dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 704				dpm_save_failed_dev(dev_name(dev));
 705				pm_dev_err(dev, state, " early", error);
 706			}
 707		}
 708		mutex_lock(&dpm_list_mtx);
 709		put_device(dev);
 710	}
 711	mutex_unlock(&dpm_list_mtx);
 712	async_synchronize_full();
 713	dpm_show_time(starttime, state, "early");
 714	trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 715}
 716
 717/**
 718 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 719 * @state: PM transition of the system being carried out.
 720 */
 721void dpm_resume_start(pm_message_t state)
 722{
 723	dpm_resume_noirq(state);
 724	dpm_resume_early(state);
 725}
 726EXPORT_SYMBOL_GPL(dpm_resume_start);
 727
 728/**
 729 * device_resume - Execute "resume" callbacks for given device.
 730 * @dev: Device to handle.
 731 * @state: PM transition of the system being carried out.
 732 * @async: If true, the device is being resumed asynchronously.
 733 */
 734static int device_resume(struct device *dev, pm_message_t state, bool async)
 735{
 736	pm_callback_t callback = NULL;
 737	char *info = NULL;
 738	int error = 0;
 739	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 740
 741	TRACE_DEVICE(dev);
 742	TRACE_RESUME(0);
 743
 744	if (dev->power.syscore)
 745		goto Complete;
 746
 747	if (dev->power.direct_complete) {
 748		/* Match the pm_runtime_disable() in __device_suspend(). */
 749		pm_runtime_enable(dev);
 750		goto Complete;
 751	}
 752
 753	dpm_wait(dev->parent, async);
 754	dpm_watchdog_set(&wd, dev);
 755	device_lock(dev);
 756
 757	/*
 758	 * This is a fib.  But we'll allow new children to be added below
 759	 * a resumed device, even if the device hasn't been completed yet.
 760	 */
 761	dev->power.is_prepared = false;
 762
 763	if (!dev->power.is_suspended)
 764		goto Unlock;
 765
 766	if (dev->pm_domain) {
 767		info = "power domain ";
 768		callback = pm_op(&dev->pm_domain->ops, state);
 769		goto Driver;
 770	}
 771
 772	if (dev->type && dev->type->pm) {
 773		info = "type ";
 774		callback = pm_op(dev->type->pm, state);
 775		goto Driver;
 776	}
 777
 778	if (dev->class) {
 779		if (dev->class->pm) {
 780			info = "class ";
 781			callback = pm_op(dev->class->pm, state);
 782			goto Driver;
 783		} else if (dev->class->resume) {
 784			info = "legacy class ";
 785			callback = dev->class->resume;
 786			goto End;
 787		}
 788	}
 789
 790	if (dev->bus) {
 791		if (dev->bus->pm) {
 792			info = "bus ";
 793			callback = pm_op(dev->bus->pm, state);
 794		} else if (dev->bus->resume) {
 795			info = "legacy bus ";
 796			callback = dev->bus->resume;
 797			goto End;
 798		}
 799	}
 800
 801 Driver:
 802	if (!callback && dev->driver && dev->driver->pm) {
 803		info = "driver ";
 804		callback = pm_op(dev->driver->pm, state);
 805	}
 806
 807 End:
 808	error = dpm_run_callback(callback, dev, state, info);
 809	dev->power.is_suspended = false;
 810
 811 Unlock:
 812	device_unlock(dev);
 813	dpm_watchdog_clear(&wd);
 814
 815 Complete:
 816	complete_all(&dev->power.completion);
 817
 818	TRACE_RESUME(error);
 819
 820	return error;
 821}
 822
 823static void async_resume(void *data, async_cookie_t cookie)
 824{
 825	struct device *dev = (struct device *)data;
 826	int error;
 827
 828	error = device_resume(dev, pm_transition, true);
 829	if (error)
 830		pm_dev_err(dev, pm_transition, " async", error);
 831	put_device(dev);
 832}
 833
 834/**
 835 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 836 * @state: PM transition of the system being carried out.
 837 *
 838 * Execute the appropriate "resume" callback for all devices whose status
 839 * indicates that they are suspended.
 840 */
 841void dpm_resume(pm_message_t state)
 842{
 843	struct device *dev;
 844	ktime_t starttime = ktime_get();
 845
 846	trace_suspend_resume(TPS("dpm_resume"), state.event, true);
 847	might_sleep();
 848
 849	mutex_lock(&dpm_list_mtx);
 850	pm_transition = state;
 851	async_error = 0;
 852
 853	list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 854		reinit_completion(&dev->power.completion);
 855		if (is_async(dev)) {
 856			get_device(dev);
 857			async_schedule(async_resume, dev);
 858		}
 859	}
 860
 861	while (!list_empty(&dpm_suspended_list)) {
 862		dev = to_device(dpm_suspended_list.next);
 863		get_device(dev);
 864		if (!is_async(dev)) {
 865			int error;
 866
 867			mutex_unlock(&dpm_list_mtx);
 868
 869			error = device_resume(dev, state, false);
 870			if (error) {
 871				suspend_stats.failed_resume++;
 872				dpm_save_failed_step(SUSPEND_RESUME);
 873				dpm_save_failed_dev(dev_name(dev));
 874				pm_dev_err(dev, state, "", error);
 875			}
 876
 877			mutex_lock(&dpm_list_mtx);
 878		}
 879		if (!list_empty(&dev->power.entry))
 880			list_move_tail(&dev->power.entry, &dpm_prepared_list);
 881		put_device(dev);
 882	}
 883	mutex_unlock(&dpm_list_mtx);
 884	async_synchronize_full();
 885	dpm_show_time(starttime, state, NULL);
 886
 887	cpufreq_resume();
 888	trace_suspend_resume(TPS("dpm_resume"), state.event, false);
 889}
 890
 891/**
 892 * device_complete - Complete a PM transition for given device.
 893 * @dev: Device to handle.
 894 * @state: PM transition of the system being carried out.
 895 */
 896static void device_complete(struct device *dev, pm_message_t state)
 897{
 898	void (*callback)(struct device *) = NULL;
 899	char *info = NULL;
 900
 901	if (dev->power.syscore)
 902		return;
 903
 904	device_lock(dev);
 905
 906	if (dev->pm_domain) {
 907		info = "completing power domain ";
 908		callback = dev->pm_domain->ops.complete;
 909	} else if (dev->type && dev->type->pm) {
 910		info = "completing type ";
 911		callback = dev->type->pm->complete;
 912	} else if (dev->class && dev->class->pm) {
 913		info = "completing class ";
 914		callback = dev->class->pm->complete;
 915	} else if (dev->bus && dev->bus->pm) {
 916		info = "completing bus ";
 917		callback = dev->bus->pm->complete;
 918	}
 919
 920	if (!callback && dev->driver && dev->driver->pm) {
 921		info = "completing driver ";
 922		callback = dev->driver->pm->complete;
 923	}
 924
 925	if (callback) {
 926		pm_dev_dbg(dev, state, info);
 927		callback(dev);
 928	}
 929
 930	device_unlock(dev);
 931
 932	pm_runtime_put(dev);
 933}
 934
 935/**
 936 * dpm_complete - Complete a PM transition for all non-sysdev devices.
 937 * @state: PM transition of the system being carried out.
 938 *
 939 * Execute the ->complete() callbacks for all devices whose PM status is not
 940 * DPM_ON (this allows new devices to be registered).
 941 */
 942void dpm_complete(pm_message_t state)
 943{
 944	struct list_head list;
 945
 946	trace_suspend_resume(TPS("dpm_complete"), state.event, true);
 947	might_sleep();
 948
 949	INIT_LIST_HEAD(&list);
 950	mutex_lock(&dpm_list_mtx);
 951	while (!list_empty(&dpm_prepared_list)) {
 952		struct device *dev = to_device(dpm_prepared_list.prev);
 953
 954		get_device(dev);
 955		dev->power.is_prepared = false;
 956		list_move(&dev->power.entry, &list);
 957		mutex_unlock(&dpm_list_mtx);
 958
 959		trace_device_pm_callback_start(dev, "", state.event);
 960		device_complete(dev, state);
 961		trace_device_pm_callback_end(dev, 0);
 962
 963		mutex_lock(&dpm_list_mtx);
 964		put_device(dev);
 965	}
 966	list_splice(&list, &dpm_list);
 967	mutex_unlock(&dpm_list_mtx);
 968
 969	/* Allow device probing and trigger re-probing of deferred devices */
 970	device_unblock_probing();
 971	trace_suspend_resume(TPS("dpm_complete"), state.event, false);
 972}
 973
 974/**
 975 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 976 * @state: PM transition of the system being carried out.
 977 *
 978 * Execute "resume" callbacks for all devices and complete the PM transition of
 979 * the system.
 980 */
 981void dpm_resume_end(pm_message_t state)
 982{
 983	dpm_resume(state);
 984	dpm_complete(state);
 985}
 986EXPORT_SYMBOL_GPL(dpm_resume_end);
 987
 988
 989/*------------------------- Suspend routines -------------------------*/
 990
 991/**
 992 * resume_event - Return a "resume" message for given "suspend" sleep state.
 993 * @sleep_state: PM message representing a sleep state.
 994 *
 995 * Return a PM message representing the resume event corresponding to given
 996 * sleep state.
 997 */
 998static pm_message_t resume_event(pm_message_t sleep_state)
 999{
1000	switch (sleep_state.event) {
1001	case PM_EVENT_SUSPEND:
1002		return PMSG_RESUME;
1003	case PM_EVENT_FREEZE:
1004	case PM_EVENT_QUIESCE:
1005		return PMSG_RECOVER;
1006	case PM_EVENT_HIBERNATE:
1007		return PMSG_RESTORE;
1008	}
1009	return PMSG_ON;
1010}
1011
1012/**
1013 * device_suspend_noirq - Execute a "late suspend" callback for given device.
1014 * @dev: Device to handle.
1015 * @state: PM transition of the system being carried out.
1016 * @async: If true, the device is being suspended asynchronously.
1017 *
1018 * The driver of @dev will not receive interrupts while this function is being
1019 * executed.
1020 */
1021static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1022{
1023	pm_callback_t callback = NULL;
1024	char *info = NULL;
1025	int error = 0;
1026
1027	TRACE_DEVICE(dev);
1028	TRACE_SUSPEND(0);
1029
1030	if (async_error)
1031		goto Complete;
1032
1033	if (pm_wakeup_pending()) {
1034		async_error = -EBUSY;
1035		goto Complete;
1036	}
1037
1038	if (dev->power.syscore || dev->power.direct_complete)
1039		goto Complete;
1040
1041	dpm_wait_for_children(dev, async);
1042
1043	if (dev->pm_domain) {
1044		info = "noirq power domain ";
1045		callback = pm_noirq_op(&dev->pm_domain->ops, state);
1046	} else if (dev->type && dev->type->pm) {
1047		info = "noirq type ";
1048		callback = pm_noirq_op(dev->type->pm, state);
1049	} else if (dev->class && dev->class->pm) {
1050		info = "noirq class ";
1051		callback = pm_noirq_op(dev->class->pm, state);
1052	} else if (dev->bus && dev->bus->pm) {
1053		info = "noirq bus ";
1054		callback = pm_noirq_op(dev->bus->pm, state);
1055	}
1056
1057	if (!callback && dev->driver && dev->driver->pm) {
1058		info = "noirq driver ";
1059		callback = pm_noirq_op(dev->driver->pm, state);
1060	}
1061
1062	error = dpm_run_callback(callback, dev, state, info);
1063	if (!error)
1064		dev->power.is_noirq_suspended = true;
1065	else
1066		async_error = error;
1067
1068Complete:
1069	complete_all(&dev->power.completion);
1070	TRACE_SUSPEND(error);
1071	return error;
1072}
1073
1074static void async_suspend_noirq(void *data, async_cookie_t cookie)
1075{
1076	struct device *dev = (struct device *)data;
1077	int error;
1078
1079	error = __device_suspend_noirq(dev, pm_transition, true);
1080	if (error) {
1081		dpm_save_failed_dev(dev_name(dev));
1082		pm_dev_err(dev, pm_transition, " async", error);
1083	}
1084
1085	put_device(dev);
1086}
1087
1088static int device_suspend_noirq(struct device *dev)
1089{
1090	reinit_completion(&dev->power.completion);
1091
1092	if (is_async(dev)) {
1093		get_device(dev);
1094		async_schedule(async_suspend_noirq, dev);
1095		return 0;
1096	}
1097	return __device_suspend_noirq(dev, pm_transition, false);
1098}
1099
1100/**
1101 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1102 * @state: PM transition of the system being carried out.
1103 *
1104 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
1105 * handlers for all non-sysdev devices.
1106 */
1107int dpm_suspend_noirq(pm_message_t state)
1108{
1109	ktime_t starttime = ktime_get();
1110	int error = 0;
1111
1112	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1113	cpuidle_pause();
1114	device_wakeup_arm_wake_irqs();
1115	suspend_device_irqs();
1116	mutex_lock(&dpm_list_mtx);
1117	pm_transition = state;
1118	async_error = 0;
1119
1120	while (!list_empty(&dpm_late_early_list)) {
1121		struct device *dev = to_device(dpm_late_early_list.prev);
1122
1123		get_device(dev);
1124		mutex_unlock(&dpm_list_mtx);
1125
1126		error = device_suspend_noirq(dev);
1127
1128		mutex_lock(&dpm_list_mtx);
1129		if (error) {
1130			pm_dev_err(dev, state, " noirq", error);
1131			dpm_save_failed_dev(dev_name(dev));
1132			put_device(dev);
1133			break;
1134		}
1135		if (!list_empty(&dev->power.entry))
1136			list_move(&dev->power.entry, &dpm_noirq_list);
1137		put_device(dev);
1138
1139		if (async_error)
1140			break;
1141	}
1142	mutex_unlock(&dpm_list_mtx);
1143	async_synchronize_full();
1144	if (!error)
1145		error = async_error;
1146
1147	if (error) {
1148		suspend_stats.failed_suspend_noirq++;
1149		dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1150		dpm_resume_noirq(resume_event(state));
1151	} else {
1152		dpm_show_time(starttime, state, "noirq");
1153	}
1154	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1155	return error;
1156}
1157
1158/**
1159 * device_suspend_late - Execute a "late suspend" callback for given device.
1160 * @dev: Device to handle.
1161 * @state: PM transition of the system being carried out.
1162 * @async: If true, the device is being suspended asynchronously.
1163 *
1164 * Runtime PM is disabled for @dev while this function is being executed.
1165 */
1166static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1167{
1168	pm_callback_t callback = NULL;
1169	char *info = NULL;
1170	int error = 0;
1171
1172	TRACE_DEVICE(dev);
1173	TRACE_SUSPEND(0);
1174
1175	__pm_runtime_disable(dev, false);
1176
1177	if (async_error)
1178		goto Complete;
1179
1180	if (pm_wakeup_pending()) {
1181		async_error = -EBUSY;
1182		goto Complete;
1183	}
1184
1185	if (dev->power.syscore || dev->power.direct_complete)
1186		goto Complete;
1187
1188	dpm_wait_for_children(dev, async);
1189
1190	if (dev->pm_domain) {
1191		info = "late power domain ";
1192		callback = pm_late_early_op(&dev->pm_domain->ops, state);
1193	} else if (dev->type && dev->type->pm) {
1194		info = "late type ";
1195		callback = pm_late_early_op(dev->type->pm, state);
1196	} else if (dev->class && dev->class->pm) {
1197		info = "late class ";
1198		callback = pm_late_early_op(dev->class->pm, state);
1199	} else if (dev->bus && dev->bus->pm) {
1200		info = "late bus ";
1201		callback = pm_late_early_op(dev->bus->pm, state);
1202	}
1203
1204	if (!callback && dev->driver && dev->driver->pm) {
1205		info = "late driver ";
1206		callback = pm_late_early_op(dev->driver->pm, state);
1207	}
1208
1209	error = dpm_run_callback(callback, dev, state, info);
1210	if (!error)
1211		dev->power.is_late_suspended = true;
1212	else
1213		async_error = error;
1214
1215Complete:
1216	TRACE_SUSPEND(error);
1217	complete_all(&dev->power.completion);
1218	return error;
1219}
1220
1221static void async_suspend_late(void *data, async_cookie_t cookie)
1222{
1223	struct device *dev = (struct device *)data;
1224	int error;
1225
1226	error = __device_suspend_late(dev, pm_transition, true);
1227	if (error) {
1228		dpm_save_failed_dev(dev_name(dev));
1229		pm_dev_err(dev, pm_transition, " async", error);
1230	}
1231	put_device(dev);
1232}
1233
1234static int device_suspend_late(struct device *dev)
1235{
1236	reinit_completion(&dev->power.completion);
1237
1238	if (is_async(dev)) {
1239		get_device(dev);
1240		async_schedule(async_suspend_late, dev);
1241		return 0;
1242	}
1243
1244	return __device_suspend_late(dev, pm_transition, false);
1245}
1246
1247/**
1248 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1249 * @state: PM transition of the system being carried out.
1250 */
1251int dpm_suspend_late(pm_message_t state)
1252{
1253	ktime_t starttime = ktime_get();
1254	int error = 0;
1255
1256	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1257	mutex_lock(&dpm_list_mtx);
1258	pm_transition = state;
1259	async_error = 0;
1260
1261	while (!list_empty(&dpm_suspended_list)) {
1262		struct device *dev = to_device(dpm_suspended_list.prev);
1263
1264		get_device(dev);
1265		mutex_unlock(&dpm_list_mtx);
1266
1267		error = device_suspend_late(dev);
1268
1269		mutex_lock(&dpm_list_mtx);
1270		if (error) {
1271			pm_dev_err(dev, state, " late", error);
1272			dpm_save_failed_dev(dev_name(dev));
1273			put_device(dev);
1274			break;
1275		}
1276		if (!list_empty(&dev->power.entry))
1277			list_move(&dev->power.entry, &dpm_late_early_list);
1278		put_device(dev);
1279
1280		if (async_error)
1281			break;
1282	}
1283	mutex_unlock(&dpm_list_mtx);
1284	async_synchronize_full();
1285	if (!error)
1286		error = async_error;
1287	if (error) {
1288		suspend_stats.failed_suspend_late++;
1289		dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1290		dpm_resume_early(resume_event(state));
1291	} else {
1292		dpm_show_time(starttime, state, "late");
1293	}
1294	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1295	return error;
1296}
1297
1298/**
1299 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1300 * @state: PM transition of the system being carried out.
1301 */
1302int dpm_suspend_end(pm_message_t state)
1303{
1304	int error = dpm_suspend_late(state);
1305	if (error)
1306		return error;
1307
1308	error = dpm_suspend_noirq(state);
1309	if (error) {
1310		dpm_resume_early(resume_event(state));
1311		return error;
1312	}
1313
1314	return 0;
1315}
1316EXPORT_SYMBOL_GPL(dpm_suspend_end);
1317
1318/**
1319 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1320 * @dev: Device to suspend.
1321 * @state: PM transition of the system being carried out.
1322 * @cb: Suspend callback to execute.
1323 * @info: string description of caller.
1324 */
1325static int legacy_suspend(struct device *dev, pm_message_t state,
1326			  int (*cb)(struct device *dev, pm_message_t state),
1327			  char *info)
1328{
1329	int error;
1330	ktime_t calltime;
1331
1332	calltime = initcall_debug_start(dev);
1333
1334	trace_device_pm_callback_start(dev, info, state.event);
1335	error = cb(dev, state);
1336	trace_device_pm_callback_end(dev, error);
1337	suspend_report_result(cb, error);
1338
1339	initcall_debug_report(dev, calltime, error, state, info);
1340
1341	return error;
1342}
1343
1344/**
1345 * device_suspend - Execute "suspend" callbacks for given device.
1346 * @dev: Device to handle.
1347 * @state: PM transition of the system being carried out.
1348 * @async: If true, the device is being suspended asynchronously.
1349 */
1350static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1351{
1352	pm_callback_t callback = NULL;
1353	char *info = NULL;
1354	int error = 0;
1355	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1356
1357	TRACE_DEVICE(dev);
1358	TRACE_SUSPEND(0);
1359
1360	dpm_wait_for_children(dev, async);
1361
1362	if (async_error)
1363		goto Complete;
1364
1365	/*
1366	 * If a device configured to wake up the system from sleep states
1367	 * has been suspended at run time and there's a resume request pending
1368	 * for it, this is equivalent to the device signaling wakeup, so the
1369	 * system suspend operation should be aborted.
1370	 */
1371	if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1372		pm_wakeup_event(dev, 0);
1373
1374	if (pm_wakeup_pending()) {
1375		async_error = -EBUSY;
1376		goto Complete;
1377	}
1378
1379	if (dev->power.syscore)
1380		goto Complete;
1381
1382	if (dev->power.direct_complete) {
1383		if (pm_runtime_status_suspended(dev)) {
1384			pm_runtime_disable(dev);
1385			if (pm_runtime_status_suspended(dev))
1386				goto Complete;
1387
1388			pm_runtime_enable(dev);
1389		}
1390		dev->power.direct_complete = false;
1391	}
1392
1393	dpm_watchdog_set(&wd, dev);
1394	device_lock(dev);
1395
1396	if (dev->pm_domain) {
1397		info = "power domain ";
1398		callback = pm_op(&dev->pm_domain->ops, state);
1399		goto Run;
1400	}
1401
1402	if (dev->type && dev->type->pm) {
1403		info = "type ";
1404		callback = pm_op(dev->type->pm, state);
1405		goto Run;
1406	}
1407
1408	if (dev->class) {
1409		if (dev->class->pm) {
1410			info = "class ";
1411			callback = pm_op(dev->class->pm, state);
1412			goto Run;
1413		} else if (dev->class->suspend) {
1414			pm_dev_dbg(dev, state, "legacy class ");
1415			error = legacy_suspend(dev, state, dev->class->suspend,
1416						"legacy class ");
1417			goto End;
1418		}
1419	}
1420
1421	if (dev->bus) {
1422		if (dev->bus->pm) {
1423			info = "bus ";
1424			callback = pm_op(dev->bus->pm, state);
1425		} else if (dev->bus->suspend) {
1426			pm_dev_dbg(dev, state, "legacy bus ");
1427			error = legacy_suspend(dev, state, dev->bus->suspend,
1428						"legacy bus ");
1429			goto End;
1430		}
1431	}
1432
1433 Run:
1434	if (!callback && dev->driver && dev->driver->pm) {
1435		info = "driver ";
1436		callback = pm_op(dev->driver->pm, state);
1437	}
1438
1439	error = dpm_run_callback(callback, dev, state, info);
1440
1441 End:
1442	if (!error) {
1443		struct device *parent = dev->parent;
1444
1445		dev->power.is_suspended = true;
1446		if (parent) {
1447			spin_lock_irq(&parent->power.lock);
1448
1449			dev->parent->power.direct_complete = false;
1450			if (dev->power.wakeup_path
1451			    && !dev->parent->power.ignore_children)
1452				dev->parent->power.wakeup_path = true;
1453
1454			spin_unlock_irq(&parent->power.lock);
1455		}
1456	}
1457
1458	device_unlock(dev);
1459	dpm_watchdog_clear(&wd);
1460
1461 Complete:
1462	complete_all(&dev->power.completion);
1463	if (error)
1464		async_error = error;
1465
1466	TRACE_SUSPEND(error);
1467	return error;
1468}
1469
1470static void async_suspend(void *data, async_cookie_t cookie)
1471{
1472	struct device *dev = (struct device *)data;
1473	int error;
1474
1475	error = __device_suspend(dev, pm_transition, true);
1476	if (error) {
1477		dpm_save_failed_dev(dev_name(dev));
1478		pm_dev_err(dev, pm_transition, " async", error);
1479	}
1480
1481	put_device(dev);
1482}
1483
1484static int device_suspend(struct device *dev)
1485{
1486	reinit_completion(&dev->power.completion);
1487
1488	if (is_async(dev)) {
1489		get_device(dev);
1490		async_schedule(async_suspend, dev);
1491		return 0;
1492	}
1493
1494	return __device_suspend(dev, pm_transition, false);
1495}
1496
1497/**
1498 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1499 * @state: PM transition of the system being carried out.
1500 */
1501int dpm_suspend(pm_message_t state)
1502{
1503	ktime_t starttime = ktime_get();
1504	int error = 0;
1505
1506	trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1507	might_sleep();
1508
1509	cpufreq_suspend();
1510
1511	mutex_lock(&dpm_list_mtx);
1512	pm_transition = state;
1513	async_error = 0;
1514	while (!list_empty(&dpm_prepared_list)) {
1515		struct device *dev = to_device(dpm_prepared_list.prev);
1516
1517		get_device(dev);
1518		mutex_unlock(&dpm_list_mtx);
1519
1520		error = device_suspend(dev);
1521
1522		mutex_lock(&dpm_list_mtx);
1523		if (error) {
1524			pm_dev_err(dev, state, "", error);
1525			dpm_save_failed_dev(dev_name(dev));
1526			put_device(dev);
1527			break;
1528		}
1529		if (!list_empty(&dev->power.entry))
1530			list_move(&dev->power.entry, &dpm_suspended_list);
1531		put_device(dev);
1532		if (async_error)
1533			break;
1534	}
1535	mutex_unlock(&dpm_list_mtx);
1536	async_synchronize_full();
1537	if (!error)
1538		error = async_error;
1539	if (error) {
1540		suspend_stats.failed_suspend++;
1541		dpm_save_failed_step(SUSPEND_SUSPEND);
1542	} else
1543		dpm_show_time(starttime, state, NULL);
1544	trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1545	return error;
1546}
1547
1548/**
1549 * device_prepare - Prepare a device for system power transition.
1550 * @dev: Device to handle.
1551 * @state: PM transition of the system being carried out.
1552 *
1553 * Execute the ->prepare() callback(s) for given device.  No new children of the
1554 * device may be registered after this function has returned.
1555 */
1556static int device_prepare(struct device *dev, pm_message_t state)
1557{
1558	int (*callback)(struct device *) = NULL;
1559	char *info = NULL;
1560	int ret = 0;
1561
1562	if (dev->power.syscore)
1563		return 0;
1564
1565	/*
1566	 * If a device's parent goes into runtime suspend at the wrong time,
1567	 * it won't be possible to resume the device.  To prevent this we
1568	 * block runtime suspend here, during the prepare phase, and allow
1569	 * it again during the complete phase.
1570	 */
1571	pm_runtime_get_noresume(dev);
1572
1573	device_lock(dev);
1574
1575	dev->power.wakeup_path = device_may_wakeup(dev);
1576
1577	if (dev->power.no_pm_callbacks) {
1578		ret = 1;	/* Let device go direct_complete */
1579		goto unlock;
1580	}
1581
1582	if (dev->pm_domain) {
1583		info = "preparing power domain ";
1584		callback = dev->pm_domain->ops.prepare;
1585	} else if (dev->type && dev->type->pm) {
1586		info = "preparing type ";
1587		callback = dev->type->pm->prepare;
1588	} else if (dev->class && dev->class->pm) {
1589		info = "preparing class ";
1590		callback = dev->class->pm->prepare;
1591	} else if (dev->bus && dev->bus->pm) {
1592		info = "preparing bus ";
1593		callback = dev->bus->pm->prepare;
1594	}
1595
1596	if (!callback && dev->driver && dev->driver->pm) {
1597		info = "preparing driver ";
1598		callback = dev->driver->pm->prepare;
1599	}
1600
1601	if (callback)
1602		ret = callback(dev);
 
 
1603
1604unlock:
1605	device_unlock(dev);
1606
1607	if (ret < 0) {
1608		suspend_report_result(callback, ret);
1609		pm_runtime_put(dev);
1610		return ret;
1611	}
1612	/*
1613	 * A positive return value from ->prepare() means "this device appears
1614	 * to be runtime-suspended and its state is fine, so if it really is
1615	 * runtime-suspended, you can leave it in that state provided that you
1616	 * will do the same thing with all of its descendants".  This only
1617	 * applies to suspend transitions, however.
1618	 */
1619	spin_lock_irq(&dev->power.lock);
1620	dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND;
1621	spin_unlock_irq(&dev->power.lock);
1622	return 0;
1623}
1624
1625/**
1626 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1627 * @state: PM transition of the system being carried out.
1628 *
1629 * Execute the ->prepare() callback(s) for all devices.
1630 */
1631int dpm_prepare(pm_message_t state)
1632{
1633	int error = 0;
1634
1635	trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1636	might_sleep();
1637
1638	/*
1639	 * Give a chance for the known devices to complete their probes, before
1640	 * disable probing of devices. This sync point is important at least
1641	 * at boot time + hibernation restore.
1642	 */
1643	wait_for_device_probe();
1644	/*
1645	 * It is unsafe if probing of devices will happen during suspend or
1646	 * hibernation and system behavior will be unpredictable in this case.
1647	 * So, let's prohibit device's probing here and defer their probes
1648	 * instead. The normal behavior will be restored in dpm_complete().
1649	 */
1650	device_block_probing();
1651
1652	mutex_lock(&dpm_list_mtx);
1653	while (!list_empty(&dpm_list)) {
1654		struct device *dev = to_device(dpm_list.next);
1655
1656		get_device(dev);
1657		mutex_unlock(&dpm_list_mtx);
1658
1659		trace_device_pm_callback_start(dev, "", state.event);
1660		error = device_prepare(dev, state);
1661		trace_device_pm_callback_end(dev, error);
1662
1663		mutex_lock(&dpm_list_mtx);
1664		if (error) {
1665			if (error == -EAGAIN) {
1666				put_device(dev);
1667				error = 0;
1668				continue;
1669			}
1670			printk(KERN_INFO "PM: Device %s not prepared "
1671				"for power transition: code %d\n",
1672				dev_name(dev), error);
1673			put_device(dev);
1674			break;
1675		}
1676		dev->power.is_prepared = true;
1677		if (!list_empty(&dev->power.entry))
1678			list_move_tail(&dev->power.entry, &dpm_prepared_list);
1679		put_device(dev);
1680	}
1681	mutex_unlock(&dpm_list_mtx);
1682	trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1683	return error;
1684}
1685
1686/**
1687 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1688 * @state: PM transition of the system being carried out.
1689 *
1690 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1691 * callbacks for them.
1692 */
1693int dpm_suspend_start(pm_message_t state)
1694{
1695	int error;
1696
1697	error = dpm_prepare(state);
1698	if (error) {
1699		suspend_stats.failed_prepare++;
1700		dpm_save_failed_step(SUSPEND_PREPARE);
1701	} else
1702		error = dpm_suspend(state);
1703	return error;
1704}
1705EXPORT_SYMBOL_GPL(dpm_suspend_start);
1706
1707void __suspend_report_result(const char *function, void *fn, int ret)
1708{
1709	if (ret)
1710		printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1711}
1712EXPORT_SYMBOL_GPL(__suspend_report_result);
1713
1714/**
1715 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1716 * @dev: Device to wait for.
1717 * @subordinate: Device that needs to wait for @dev.
1718 */
1719int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1720{
1721	dpm_wait(dev, subordinate->power.async_suspend);
1722	return async_error;
1723}
1724EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1725
1726/**
1727 * dpm_for_each_dev - device iterator.
1728 * @data: data for the callback.
1729 * @fn: function to be called for each device.
1730 *
1731 * Iterate over devices in dpm_list, and call @fn for each device,
1732 * passing it @data.
1733 */
1734void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1735{
1736	struct device *dev;
1737
1738	if (!fn)
1739		return;
1740
1741	device_pm_lock();
1742	list_for_each_entry(dev, &dpm_list, power.entry)
1743		fn(dev, data);
1744	device_pm_unlock();
1745}
1746EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1747
1748static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1749{
1750	if (!ops)
1751		return true;
1752
1753	return !ops->prepare &&
1754	       !ops->suspend &&
1755	       !ops->suspend_late &&
1756	       !ops->suspend_noirq &&
1757	       !ops->resume_noirq &&
1758	       !ops->resume_early &&
1759	       !ops->resume &&
1760	       !ops->complete;
1761}
1762
1763void device_pm_check_callbacks(struct device *dev)
1764{
1765	spin_lock_irq(&dev->power.lock);
1766	dev->power.no_pm_callbacks =
1767		(!dev->bus || pm_ops_is_empty(dev->bus->pm)) &&
1768		(!dev->class || pm_ops_is_empty(dev->class->pm)) &&
1769		(!dev->type || pm_ops_is_empty(dev->type->pm)) &&
1770		(!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
1771		(!dev->driver || pm_ops_is_empty(dev->driver->pm));
1772	spin_unlock_irq(&dev->power.lock);
1773}