drivers/base/power/main.c

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