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/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 #include <linux/wakeup_reason.h>
  37
  38 #include <asm/current.h>
  39
  40 #include "../base.h"
  41 #include "power.h"
  42
  43 typedef int (*pm_callback_t)(struct device *);
  44
  45 /*
  46  * The entries in the dpm_list list are in a depth first order, simply
  47  * because children are guaranteed to be discovered after parents, and
  48  * are inserted at the back of the list on discovery.
  49  *
  50  * Since device_pm_add() may be called with a device lock held,
  51  * we must never try to acquire a device lock while holding
  52  * dpm_list_mutex.
  53  */
  54
  55 LIST_HEAD(dpm_list);
  56 static LIST_HEAD(dpm_prepared_list);
  57 static LIST_HEAD(dpm_suspended_list);
  58 static LIST_HEAD(dpm_late_early_list);
  59 static LIST_HEAD(dpm_noirq_list);
  60
  61 struct suspend_stats suspend_stats;
  62 static DEFINE_MUTEX(dpm_list_mtx);
  63 static pm_message_t pm_transition;
  64
  65 static void dpm_drv_timeout(unsigned long data);
  66 struct dpm_drv_wd_data {
  67         struct device *dev;
  68         struct task_struct *tsk;
  69 };
  70
  71 static int async_error;
  72
  73 static char *pm_verb(int event)
  74 {
  75         switch (event) {
  76         case PM_EVENT_SUSPEND:
  77                 return "suspend";
  78         case PM_EVENT_RESUME:
  79                 return "resume";
  80         case PM_EVENT_FREEZE:
  81                 return "freeze";
  82         case PM_EVENT_QUIESCE:
  83                 return "quiesce";
  84         case PM_EVENT_HIBERNATE:
  85                 return "hibernate";
  86         case PM_EVENT_THAW:
  87                 return "thaw";
  88         case PM_EVENT_RESTORE:
  89                 return "restore";
  90         case PM_EVENT_RECOVER:
  91                 return "recover";
  92         default:
  93                 return "(unknown PM event)";
  94         }
  95 }
  96
  97 /**
  98  * device_pm_sleep_init - Initialize system suspend-related device fields.
  99  * @dev: Device object being initialized.
 100  */
 101 void device_pm_sleep_init(struct device *dev)
 102 {
 103         dev->power.is_prepared = false;
 104         dev->power.is_suspended = false;
 105         dev->power.is_noirq_suspended = false;
 106         dev->power.is_late_suspended = false;
 107         init_completion(&dev->power.completion);
 108         complete_all(&dev->power.completion);
 109         dev->power.wakeup = NULL;
 110         INIT_LIST_HEAD(&dev->power.entry);
 111 }
 112
 113 /**
 114  * device_pm_lock - Lock the list of active devices used by the PM core.
 115  */
 116 void device_pm_lock(void)
 117 {
 118         mutex_lock(&dpm_list_mtx);
 119 }
 120
 121 /**
 122  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 123  */
 124 void device_pm_unlock(void)
 125 {
 126         mutex_unlock(&dpm_list_mtx);
 127 }
 128
 129 /**
 130  * device_pm_add - Add a device to the PM core's list of active devices.
 131  * @dev: Device to add to the list.
 132  */
 133 void device_pm_add(struct device *dev)
 134 {
 135         pr_debug("PM: Adding info for %s:%s\n",
 136                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 137         mutex_lock(&dpm_list_mtx);
 138         if (dev->parent && dev->parent->power.is_prepared)
 139                 dev_warn(dev, "parent %s should not be sleeping\n",
 140                         dev_name(dev->parent));
 141         list_add_tail(&dev->power.entry, &dpm_list);
 142         mutex_unlock(&dpm_list_mtx);
 143 }
 144
 145 /**
 146  * device_pm_remove - Remove a device from the PM core's list of active devices.
 147  * @dev: Device to be removed from the list.
 148  */
 149 void device_pm_remove(struct device *dev)
 150 {
 151         pr_debug("PM: Removing info for %s:%s\n",
 152                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 153         complete_all(&dev->power.completion);
 154         mutex_lock(&dpm_list_mtx);
 155         list_del_init(&dev->power.entry);
 156         mutex_unlock(&dpm_list_mtx);
 157         device_wakeup_disable(dev);
 158         pm_runtime_remove(dev);
 159 }
 160
 161 /**
 162  * device_pm_move_before - Move device in the PM core's list of active devices.
 163  * @deva: Device to move in dpm_list.
 164  * @devb: Device @deva should come before.
 165  */
 166 void device_pm_move_before(struct device *deva, struct device *devb)
 167 {
 168         pr_debug("PM: Moving %s:%s before %s:%s\n",
 169                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 170                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 171         /* Delete deva from dpm_list and reinsert before devb. */
 172         list_move_tail(&deva->power.entry, &devb->power.entry);
 173 }
 174
 175 /**
 176  * device_pm_move_after - Move device in the PM core's list of active devices.
 177  * @deva: Device to move in dpm_list.
 178  * @devb: Device @deva should come after.
 179  */
 180 void device_pm_move_after(struct device *deva, struct device *devb)
 181 {
 182         pr_debug("PM: Moving %s:%s after %s:%s\n",
 183                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 184                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 185         /* Delete deva from dpm_list and reinsert after devb. */
 186         list_move(&deva->power.entry, &devb->power.entry);
 187 }
 188
 189 /**
 190  * device_pm_move_last - Move device to end of the PM core's list of devices.
 191  * @dev: Device to move in dpm_list.
 192  */
 193 void device_pm_move_last(struct device *dev)
 194 {
 195         pr_debug("PM: Moving %s:%s to end of list\n",
 196                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 197         list_move_tail(&dev->power.entry, &dpm_list);
 198 }
 199
 200 static ktime_t initcall_debug_start(struct device *dev)
 201 {
 202         ktime_t calltime = ktime_set(0, 0);
 203
 204         if (pm_print_times_enabled) {
 205                 pr_info("calling  %s+ @ %i, parent: %s\n",
 206                         dev_name(dev), task_pid_nr(current),
 207                         dev->parent ? dev_name(dev->parent) : "none");
 208                 calltime = ktime_get();
 209         }
 210
 211         return calltime;
 212 }
 213
 214 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 215                                   int error, pm_message_t state, char *info)
 216 {
 217         ktime_t rettime;
 218         s64 nsecs;
 219
 220         rettime = ktime_get();
 221         nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 222
 223         if (pm_print_times_enabled) {
 224                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 225                         error, (unsigned long long)nsecs >> 10);
 226         }
 227 }
 228
 229 /**
 230  * dpm_wait - Wait for a PM operation to complete.
 231  * @dev: Device to wait for.
 232  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 233  */
 234 static void dpm_wait(struct device *dev, bool async)
 235 {
 236         if (!dev)
 237                 return;
 238
 239         if (async || (pm_async_enabled && dev->power.async_suspend))
 240                 wait_for_completion(&dev->power.completion);
 241 }
 242
 243 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 244 {
 245         dpm_wait(dev, *((bool *)async_ptr));
 246         return 0;
 247 }
 248
 249 static void dpm_wait_for_children(struct device *dev, bool async)
 250 {
 251        device_for_each_child(dev, &async, dpm_wait_fn);
 252 }
 253
 254 /**
 255  * pm_op - Return the PM operation appropriate for given PM event.
 256  * @ops: PM operations to choose from.
 257  * @state: PM transition of the system being carried out.
 258  */
 259 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 260 {
 261         switch (state.event) {
 262 #ifdef CONFIG_SUSPEND
 263         case PM_EVENT_SUSPEND:
 264                 return ops->suspend;
 265         case PM_EVENT_RESUME:
 266                 return ops->resume;
 267 #endif /* CONFIG_SUSPEND */
 268 #ifdef CONFIG_HIBERNATE_CALLBACKS
 269         case PM_EVENT_FREEZE:
 270         case PM_EVENT_QUIESCE:
 271                 return ops->freeze;
 272         case PM_EVENT_HIBERNATE:
 273                 return ops->poweroff;
 274         case PM_EVENT_THAW:
 275         case PM_EVENT_RECOVER:
 276                 return ops->thaw;
 277                 break;
 278         case PM_EVENT_RESTORE:
 279                 return ops->restore;
 280 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 281         }
 282
 283         return NULL;
 284 }
 285
 286 /**
 287  * pm_late_early_op - Return the PM operation appropriate for given PM event.
 288  * @ops: PM operations to choose from.
 289  * @state: PM transition of the system being carried out.
 290  *
 291  * Runtime PM is disabled for @dev while this function is being executed.
 292  */
 293 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 294                                       pm_message_t state)
 295 {
 296         switch (state.event) {
 297 #ifdef CONFIG_SUSPEND
 298         case PM_EVENT_SUSPEND:
 299                 return ops->suspend_late;
 300         case PM_EVENT_RESUME:
 301                 return ops->resume_early;
 302 #endif /* CONFIG_SUSPEND */
 303 #ifdef CONFIG_HIBERNATE_CALLBACKS
 304         case PM_EVENT_FREEZE:
 305         case PM_EVENT_QUIESCE:
 306                 return ops->freeze_late;
 307         case PM_EVENT_HIBERNATE:
 308                 return ops->poweroff_late;
 309         case PM_EVENT_THAW:
 310         case PM_EVENT_RECOVER:
 311                 return ops->thaw_early;
 312         case PM_EVENT_RESTORE:
 313                 return ops->restore_early;
 314 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 315         }
 316
 317         return NULL;
 318 }
 319
 320 /**
 321  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 322  * @ops: PM operations to choose from.
 323  * @state: PM transition of the system being carried out.
 324  *
 325  * The driver of @dev will not receive interrupts while this function is being
 326  * executed.
 327  */
 328 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 329 {
 330         switch (state.event) {
 331 #ifdef CONFIG_SUSPEND
 332         case PM_EVENT_SUSPEND:
 333                 return ops->suspend_noirq;
 334         case PM_EVENT_RESUME:
 335                 return ops->resume_noirq;
 336 #endif /* CONFIG_SUSPEND */
 337 #ifdef CONFIG_HIBERNATE_CALLBACKS
 338         case PM_EVENT_FREEZE:
 339         case PM_EVENT_QUIESCE:
 340                 return ops->freeze_noirq;
 341         case PM_EVENT_HIBERNATE:
 342                 return ops->poweroff_noirq;
 343         case PM_EVENT_THAW:
 344         case PM_EVENT_RECOVER:
 345                 return ops->thaw_noirq;
 346         case PM_EVENT_RESTORE:
 347                 return ops->restore_noirq;
 348 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 349         }
 350
 351         return NULL;
 352 }
 353
 354 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 355 {
 356         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 357                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 358                 ", may wakeup" : "");
 359 }
 360
 361 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 362                         int error)
 363 {
 364         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 365                 dev_name(dev), pm_verb(state.event), info, error);
 366 }
 367
 368 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 369 {
 370         ktime_t calltime;
 371         u64 usecs64;
 372         int usecs;
 373
 374         calltime = ktime_get();
 375         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 376         do_div(usecs64, NSEC_PER_USEC);
 377         usecs = usecs64;
 378         if (usecs == 0)
 379                 usecs = 1;
 380         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 381                 info ?: "", info ? " " : "", pm_verb(state.event),
 382                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 383 }
 384
 385 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 386                             pm_message_t state, char *info)
 387 {
 388         ktime_t calltime;
 389         int error;
 390
 391         if (!cb)
 392                 return 0;
 393
 394         calltime = initcall_debug_start(dev);
 395
 396         pm_dev_dbg(dev, state, info);
 397         trace_device_pm_callback_start(dev, info, state.event);
 398         error = cb(dev);
 399         trace_device_pm_callback_end(dev, error);
 400         suspend_report_result(cb, error);
 401
 402         initcall_debug_report(dev, calltime, error, state, info);
 403
 404         return error;
 405 }
 406
 407 #ifdef CONFIG_DPM_WATCHDOG
 408 struct dpm_watchdog {
 409         struct device           *dev;
 410         struct task_struct      *tsk;
 411         struct timer_list       timer;
 412 };
 413
 414 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 415         struct dpm_watchdog wd
 416
 417 /**
 418  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 419  * @data: Watchdog object address.
 420  *
 421  * Called when a driver has timed out suspending or resuming.
 422  * There's not much we can do here to recover so panic() to
 423  * capture a crash-dump in pstore.
 424  */
 425 static void dpm_watchdog_handler(unsigned long data)
 426 {
 427         struct dpm_watchdog *wd = (void *)data;
 428
 429         dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 430         show_stack(wd->tsk, NULL);
 431         panic("%s %s: unrecoverable failure\n",
 432                 dev_driver_string(wd->dev), dev_name(wd->dev));
 433 }
 434
 435 /**
 436  * dpm_watchdog_set - Enable pm watchdog for given device.
 437  * @wd: Watchdog. Must be allocated on the stack.
 438  * @dev: Device to handle.
 439  */
 440 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 441 {
 442         struct timer_list *timer = &wd->timer;
 443
 444         wd->dev = dev;
 445         wd->tsk = current;
 446
 447         init_timer_on_stack(timer);
 448         /* use same timeout value for both suspend and resume */
 449         timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 450         timer->function = dpm_watchdog_handler;
 451         timer->data = (unsigned long)wd;
 452         add_timer(timer);
 453 }
 454
 455 /**
 456  * dpm_watchdog_clear - Disable suspend/resume watchdog.
 457  * @wd: Watchdog to disable.
 458  */
 459 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 460 {
 461         struct timer_list *timer = &wd->timer;
 462
 463         del_timer_sync(timer);
 464         destroy_timer_on_stack(timer);
 465 }
 466 #else
 467 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 468 #define dpm_watchdog_set(x, y)
 469 #define dpm_watchdog_clear(x)
 470 #endif
 471
 472 /*------------------------- Resume routines -------------------------*/
 473
 474 /**
 475  * device_resume_noirq - Execute an "early resume" callback for given device.
 476  * @dev: Device to handle.
 477  * @state: PM transition of the system being carried out.
 478  * @async: If true, the device is being resumed asynchronously.
 479  *
 480  * The driver of @dev will not receive interrupts while this function is being
 481  * executed.
 482  */
 483 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 484 {
 485         pm_callback_t callback = NULL;
 486         char *info = NULL;
 487         int error = 0;
 488
 489         TRACE_DEVICE(dev);
 490         TRACE_RESUME(0);
 491
 492         if (dev->power.syscore || dev->power.direct_complete)
 493                 goto Out;
 494
 495         if (!dev->power.is_noirq_suspended)
 496                 goto Out;
 497
 498         dpm_wait(dev->parent, async);
 499
 500         if (dev->pm_domain) {
 501                 info = "noirq power domain ";
 502                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 503         } else if (dev->type && dev->type->pm) {
 504                 info = "noirq type ";
 505                 callback = pm_noirq_op(dev->type->pm, state);
 506         } else if (dev->class && dev->class->pm) {
 507                 info = "noirq class ";
 508                 callback = pm_noirq_op(dev->class->pm, state);
 509         } else if (dev->bus && dev->bus->pm) {
 510                 info = "noirq bus ";
 511                 callback = pm_noirq_op(dev->bus->pm, state);
 512         }
 513
 514         if (!callback && dev->driver && dev->driver->pm) {
 515                 info = "noirq driver ";
 516                 callback = pm_noirq_op(dev->driver->pm, state);
 517         }
 518
 519         error = dpm_run_callback(callback, dev, state, info);
 520         dev->power.is_noirq_suspended = false;
 521
 522  Out:
 523         complete_all(&dev->power.completion);
 524         TRACE_RESUME(error);
 525         return error;
 526 }
 527
 528 static bool is_async(struct device *dev)
 529 {
 530         return dev->power.async_suspend && pm_async_enabled
 531                 && !pm_trace_is_enabled();
 532 }
 533
 534 static void async_resume_noirq(void *data, async_cookie_t cookie)
 535 {
 536         struct device *dev = (struct device *)data;
 537         int error;
 538
 539         error = device_resume_noirq(dev, pm_transition, true);
 540         if (error)
 541                 pm_dev_err(dev, pm_transition, " async", error);
 542
 543         put_device(dev);
 544 }
 545
 546 /**
 547  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 548  * @state: PM transition of the system being carried out.
 549  *
 550  * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
 551  * enable device drivers to receive interrupts.
 552  */
 553 void dpm_resume_noirq(pm_message_t state)
 554 {
 555         struct device *dev;
 556         ktime_t starttime = ktime_get();
 557
 558         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 559         mutex_lock(&dpm_list_mtx);
 560         pm_transition = state;
 561
 562         /*
 563          * Advanced the async threads upfront,
 564          * in case the starting of async threads is
 565          * delayed by non-async resuming devices.
 566          */
 567         list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
 568                 reinit_completion(&dev->power.completion);
 569                 if (is_async(dev)) {
 570                         get_device(dev);
 571                         async_schedule(async_resume_noirq, dev);
 572                 }
 573         }
 574
 575         while (!list_empty(&dpm_noirq_list)) {
 576                 dev = to_device(dpm_noirq_list.next);
 577                 get_device(dev);
 578                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 579                 mutex_unlock(&dpm_list_mtx);
 580
 581                 if (!is_async(dev)) {
 582                         int error;
 583
 584                         error = device_resume_noirq(dev, state, false);
 585                         if (error) {
 586                                 suspend_stats.failed_resume_noirq++;
 587                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 588                                 dpm_save_failed_dev(dev_name(dev));
 589                                 pm_dev_err(dev, state, " noirq", error);
 590                         }
 591                 }
 592
 593                 mutex_lock(&dpm_list_mtx);
 594                 put_device(dev);
 595         }
 596         mutex_unlock(&dpm_list_mtx);
 597         async_synchronize_full();
 598         dpm_show_time(starttime, state, "noirq");
 599         resume_device_irqs();
 600         device_wakeup_disarm_wake_irqs();
 601         cpuidle_resume();
 602         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 603 }
 604
 605 /**
 606  * device_resume_early - Execute an "early resume" callback for given device.
 607  * @dev: Device to handle.
 608  * @state: PM transition of the system being carried out.
 609  * @async: If true, the device is being resumed asynchronously.
 610  *
 611  * Runtime PM is disabled for @dev while this function is being executed.
 612  */
 613 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 614 {
 615         pm_callback_t callback = NULL;
 616         char *info = NULL;
 617         int error = 0;
 618
 619         TRACE_DEVICE(dev);
 620         TRACE_RESUME(0);
 621
 622         if (dev->power.syscore || dev->power.direct_complete)
 623                 goto Out;
 624
 625         if (!dev->power.is_late_suspended)
 626                 goto Out;
 627
 628         dpm_wait(dev->parent, async);
 629
 630         if (dev->pm_domain) {
 631                 info = "early power domain ";
 632                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 633         } else if (dev->type && dev->type->pm) {
 634                 info = "early type ";
 635                 callback = pm_late_early_op(dev->type->pm, state);
 636         } else if (dev->class && dev->class->pm) {
 637                 info = "early class ";
 638                 callback = pm_late_early_op(dev->class->pm, state);
 639         } else if (dev->bus && dev->bus->pm) {
 640                 info = "early bus ";
 641                 callback = pm_late_early_op(dev->bus->pm, state);
 642         }
 643
 644         if (!callback && dev->driver && dev->driver->pm) {
 645                 info = "early driver ";
 646                 callback = pm_late_early_op(dev->driver->pm, state);
 647         }
 648
 649         error = dpm_run_callback(callback, dev, state, info);
 650         dev->power.is_late_suspended = false;
 651
 652  Out:
 653         TRACE_RESUME(error);
 654
 655         pm_runtime_enable(dev);
 656         complete_all(&dev->power.completion);
 657         return error;
 658 }
 659
 660 static void async_resume_early(void *data, async_cookie_t cookie)
 661 {
 662         struct device *dev = (struct device *)data;
 663         int error;
 664
 665         error = device_resume_early(dev, pm_transition, true);
 666         if (error)
 667                 pm_dev_err(dev, pm_transition, " async", error);
 668
 669         put_device(dev);
 670 }
 671
 672 /**
 673  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 674  * @state: PM transition of the system being carried out.
 675  */
 676 void dpm_resume_early(pm_message_t state)
 677 {
 678         struct device *dev;
 679         ktime_t starttime = ktime_get();
 680
 681         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 682         mutex_lock(&dpm_list_mtx);
 683         pm_transition = state;
 684
 685         /*
 686          * Advanced the async threads upfront,
 687          * in case the starting of async threads is
 688          * delayed by non-async resuming devices.
 689          */
 690         list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
 691                 reinit_completion(&dev->power.completion);
 692                 if (is_async(dev)) {
 693                         get_device(dev);
 694                         async_schedule(async_resume_early, dev);
 695                 }
 696         }
 697
 698         while (!list_empty(&dpm_late_early_list)) {
 699                 dev = to_device(dpm_late_early_list.next);
 700                 get_device(dev);
 701                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 702                 mutex_unlock(&dpm_list_mtx);
 703
 704                 if (!is_async(dev)) {
 705                         int error;
 706
 707                         error = device_resume_early(dev, state, false);
 708                         if (error) {
 709                                 suspend_stats.failed_resume_early++;
 710                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 711                                 dpm_save_failed_dev(dev_name(dev));
 712                                 pm_dev_err(dev, state, " early", error);
 713                         }
 714                 }
 715                 mutex_lock(&dpm_list_mtx);
 716                 put_device(dev);
 717         }
 718         mutex_unlock(&dpm_list_mtx);
 719         async_synchronize_full();
 720         dpm_show_time(starttime, state, "early");
 721         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 722 }
 723
 724 /**
 725  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 726  * @state: PM transition of the system being carried out.
 727  */
 728 void dpm_resume_start(pm_message_t state)
 729 {
 730         dpm_resume_noirq(state);
 731         dpm_resume_early(state);
 732 }
 733 EXPORT_SYMBOL_GPL(dpm_resume_start);
 734
 735 /**
 736  * device_resume - Execute "resume" callbacks for given device.
 737  * @dev: Device to handle.
 738  * @state: PM transition of the system being carried out.
 739  * @async: If true, the device is being resumed asynchronously.
 740  */
 741 static int device_resume(struct device *dev, pm_message_t state, bool async)
 742 {
 743         pm_callback_t callback = NULL;
 744         char *info = NULL;
 745         int error = 0;
 746         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 747
 748         TRACE_DEVICE(dev);
 749         TRACE_RESUME(0);
 750
 751         if (dev->power.syscore)
 752                 goto Complete;
 753
 754         if (dev->power.direct_complete) {
 755                 /* Match the pm_runtime_disable() in __device_suspend(). */
 756                 pm_runtime_enable(dev);
 757                 goto Complete;
 758         }
 759
 760         dpm_wait(dev->parent, async);
 761         dpm_watchdog_set(&wd, dev);
 762         device_lock(dev);
 763
 764         /*
 765          * This is a fib.  But we'll allow new children to be added below
 766          * a resumed device, even if the device hasn't been completed yet.
 767          */
 768         dev->power.is_prepared = false;
 769
 770         if (!dev->power.is_suspended)
 771                 goto Unlock;
 772
 773         if (dev->pm_domain) {
 774                 info = "power domain ";
 775                 callback = pm_op(&dev->pm_domain->ops, state);
 776                 goto Driver;
 777         }
 778
 779         if (dev->type && dev->type->pm) {
 780                 info = "type ";
 781                 callback = pm_op(dev->type->pm, state);
 782                 goto Driver;
 783         }
 784
 785         if (dev->class) {
 786                 if (dev->class->pm) {
 787                         info = "class ";
 788                         callback = pm_op(dev->class->pm, state);
 789                         goto Driver;
 790                 } else if (dev->class->resume) {
 791                         info = "legacy class ";
 792                         callback = dev->class->resume;
 793                         goto End;
 794                 }
 795         }
 796
 797         if (dev->bus) {
 798                 if (dev->bus->pm) {
 799                         info = "bus ";
 800                         callback = pm_op(dev->bus->pm, state);
 801                 } else if (dev->bus->resume) {
 802                         info = "legacy bus ";
 803                         callback = dev->bus->resume;
 804                         goto End;
 805                 }
 806         }
 807
 808  Driver:
 809         if (!callback && dev->driver && dev->driver->pm) {
 810                 info = "driver ";
 811                 callback = pm_op(dev->driver->pm, state);
 812         }
 813
 814  End:
 815         error = dpm_run_callback(callback, dev, state, info);
 816         dev->power.is_suspended = false;
 817
 818  Unlock:
 819         device_unlock(dev);
 820         dpm_watchdog_clear(&wd);
 821
 822  Complete:
 823         complete_all(&dev->power.completion);
 824
 825         TRACE_RESUME(error);
 826
 827         return error;
 828 }
 829
 830 static void async_resume(void *data, async_cookie_t cookie)
 831 {
 832         struct device *dev = (struct device *)data;
 833         int error;
 834
 835         error = device_resume(dev, pm_transition, true);
 836         if (error)
 837                 pm_dev_err(dev, pm_transition, " async", error);
 838         put_device(dev);
 839 }
 840
 841 /**
 842  *      dpm_drv_timeout - Driver suspend / resume watchdog handler
 843  *      @data: struct device which timed out
 844  *
 845  *      Called when a driver has timed out suspending or resuming.
 846  *      There's not much we can do here to recover so
 847  *      BUG() out for a crash-dump
 848  *
 849  */
 850 static void dpm_drv_timeout(unsigned long data)
 851 {
 852         struct dpm_drv_wd_data *wd_data = (void *)data;
 853         struct device *dev = wd_data->dev;
 854         struct task_struct *tsk = wd_data->tsk;
 855
 856         printk(KERN_EMERG "**** DPM device timeout: %s (%s)\n", dev_name(dev),
 857                (dev->driver ? dev->driver->name : "no driver"));
 858
 859         printk(KERN_EMERG "dpm suspend stack:\n");
 860         show_stack(tsk, NULL);
 861
 862         BUG();
 863 }
 864
 865 /**
 866  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 867  * @state: PM transition of the system being carried out.
 868  *
 869  * Execute the appropriate "resume" callback for all devices whose status
 870  * indicates that they are suspended.
 871  */
 872 void dpm_resume(pm_message_t state)
 873 {
 874         struct device *dev;
 875         ktime_t starttime = ktime_get();
 876
 877         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
 878         might_sleep();
 879
 880         mutex_lock(&dpm_list_mtx);
 881         pm_transition = state;
 882         async_error = 0;
 883
 884         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 885                 reinit_completion(&dev->power.completion);
 886                 if (is_async(dev)) {
 887                         get_device(dev);
 888                         async_schedule(async_resume, dev);
 889                 }
 890         }
 891
 892         while (!list_empty(&dpm_suspended_list)) {
 893                 dev = to_device(dpm_suspended_list.next);
 894                 get_device(dev);
 895                 if (!is_async(dev)) {
 896                         int error;
 897
 898                         mutex_unlock(&dpm_list_mtx);
 899
 900                         error = device_resume(dev, state, false);
 901                         if (error) {
 902                                 suspend_stats.failed_resume++;
 903                                 dpm_save_failed_step(SUSPEND_RESUME);
 904                                 dpm_save_failed_dev(dev_name(dev));
 905                                 pm_dev_err(dev, state, "", error);
 906                         }
 907
 908                         mutex_lock(&dpm_list_mtx);
 909                 }
 910                 if (!list_empty(&dev->power.entry))
 911                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 912                 put_device(dev);
 913         }
 914         mutex_unlock(&dpm_list_mtx);
 915         async_synchronize_full();
 916         dpm_show_time(starttime, state, NULL);
 917
 918         cpufreq_resume();
 919         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
 920 }
 921
 922 /**
 923  * device_complete - Complete a PM transition for given device.
 924  * @dev: Device to handle.
 925  * @state: PM transition of the system being carried out.
 926  */
 927 static void device_complete(struct device *dev, pm_message_t state)
 928 {
 929         void (*callback)(struct device *) = NULL;
 930         char *info = NULL;
 931
 932         if (dev->power.syscore)
 933                 return;
 934
 935         device_lock(dev);
 936
 937         if (dev->pm_domain) {
 938                 info = "completing power domain ";
 939                 callback = dev->pm_domain->ops.complete;
 940         } else if (dev->type && dev->type->pm) {
 941                 info = "completing type ";
 942                 callback = dev->type->pm->complete;
 943         } else if (dev->class && dev->class->pm) {
 944                 info = "completing class ";
 945                 callback = dev->class->pm->complete;
 946         } else if (dev->bus && dev->bus->pm) {
 947                 info = "completing bus ";
 948                 callback = dev->bus->pm->complete;
 949         }
 950
 951         if (!callback && dev->driver && dev->driver->pm) {
 952                 info = "completing driver ";
 953                 callback = dev->driver->pm->complete;
 954         }
 955
 956         if (callback) {
 957                 pm_dev_dbg(dev, state, info);
 958                 callback(dev);
 959         }
 960
 961         device_unlock(dev);
 962
 963         pm_runtime_put(dev);
 964 }
 965
 966 /**
 967  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 968  * @state: PM transition of the system being carried out.
 969  *
 970  * Execute the ->complete() callbacks for all devices whose PM status is not
 971  * DPM_ON (this allows new devices to be registered).
 972  */
 973 void dpm_complete(pm_message_t state)
 974 {
 975         struct list_head list;
 976
 977         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
 978         might_sleep();
 979
 980         INIT_LIST_HEAD(&list);
 981         mutex_lock(&dpm_list_mtx);
 982         while (!list_empty(&dpm_prepared_list)) {
 983                 struct device *dev = to_device(dpm_prepared_list.prev);
 984
 985                 get_device(dev);
 986                 dev->power.is_prepared = false;
 987                 list_move(&dev->power.entry, &list);
 988                 mutex_unlock(&dpm_list_mtx);
 989
 990                 trace_device_pm_callback_start(dev, "", state.event);
 991                 device_complete(dev, state);
 992                 trace_device_pm_callback_end(dev, 0);
 993
 994                 mutex_lock(&dpm_list_mtx);
 995                 put_device(dev);
 996         }
 997         list_splice(&list, &dpm_list);
 998         mutex_unlock(&dpm_list_mtx);
 999         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1000 }
1001
1002 /**
1003  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1004  * @state: PM transition of the system being carried out.
1005  *
1006  * Execute "resume" callbacks for all devices and complete the PM transition of
1007  * the system.
1008  */
1009 void dpm_resume_end(pm_message_t state)
1010 {
1011         dpm_resume(state);
1012         dpm_complete(state);
1013 }
1014 EXPORT_SYMBOL_GPL(dpm_resume_end);
1015
1016
1017 /*------------------------- Suspend routines -------------------------*/
1018
1019 /**
1020  * resume_event - Return a "resume" message for given "suspend" sleep state.
1021  * @sleep_state: PM message representing a sleep state.
1022  *
1023  * Return a PM message representing the resume event corresponding to given
1024  * sleep state.
1025  */
1026 static pm_message_t resume_event(pm_message_t sleep_state)
1027 {
1028         switch (sleep_state.event) {
1029         case PM_EVENT_SUSPEND:
1030                 return PMSG_RESUME;
1031         case PM_EVENT_FREEZE:
1032         case PM_EVENT_QUIESCE:
1033                 return PMSG_RECOVER;
1034         case PM_EVENT_HIBERNATE:
1035                 return PMSG_RESTORE;
1036         }
1037         return PMSG_ON;
1038 }
1039
1040 /**
1041  * device_suspend_noirq - Execute a "late suspend" callback for given device.
1042  * @dev: Device to handle.
1043  * @state: PM transition of the system being carried out.
1044  * @async: If true, the device is being suspended asynchronously.
1045  *
1046  * The driver of @dev will not receive interrupts while this function is being
1047  * executed.
1048  */
1049 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1050 {
1051         pm_callback_t callback = NULL;
1052         char *info = NULL;
1053         int error = 0;
1054
1055         TRACE_DEVICE(dev);
1056         TRACE_SUSPEND(0);
1057
1058         if (async_error)
1059                 goto Complete;
1060
1061         if (pm_wakeup_pending()) {
1062                 async_error = -EBUSY;
1063                 goto Complete;
1064         }
1065
1066         if (dev->power.syscore || dev->power.direct_complete)
1067                 goto Complete;
1068
1069         dpm_wait_for_children(dev, async);
1070
1071         if (dev->pm_domain) {
1072                 info = "noirq power domain ";
1073                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1074         } else if (dev->type && dev->type->pm) {
1075                 info = "noirq type ";
1076                 callback = pm_noirq_op(dev->type->pm, state);
1077         } else if (dev->class && dev->class->pm) {
1078                 info = "noirq class ";
1079                 callback = pm_noirq_op(dev->class->pm, state);
1080         } else if (dev->bus && dev->bus->pm) {
1081                 info = "noirq bus ";
1082                 callback = pm_noirq_op(dev->bus->pm, state);
1083         }
1084
1085         if (!callback && dev->driver && dev->driver->pm) {
1086                 info = "noirq driver ";
1087                 callback = pm_noirq_op(dev->driver->pm, state);
1088         }
1089
1090         error = dpm_run_callback(callback, dev, state, info);
1091         if (!error)
1092                 dev->power.is_noirq_suspended = true;
1093         else
1094                 async_error = error;
1095
1096 Complete:
1097         complete_all(&dev->power.completion);
1098         TRACE_SUSPEND(error);
1099         return error;
1100 }
1101
1102 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1103 {
1104         struct device *dev = (struct device *)data;
1105         int error;
1106
1107         error = __device_suspend_noirq(dev, pm_transition, true);
1108         if (error) {
1109                 dpm_save_failed_dev(dev_name(dev));
1110                 pm_dev_err(dev, pm_transition, " async", error);
1111         }
1112
1113         put_device(dev);
1114 }
1115
1116 static int device_suspend_noirq(struct device *dev)
1117 {
1118         reinit_completion(&dev->power.completion);
1119
1120         if (is_async(dev)) {
1121                 get_device(dev);
1122                 async_schedule(async_suspend_noirq, dev);
1123                 return 0;
1124         }
1125         return __device_suspend_noirq(dev, pm_transition, false);
1126 }
1127
1128 /**
1129  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1130  * @state: PM transition of the system being carried out.
1131  *
1132  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
1133  * handlers for all non-sysdev devices.
1134  */
1135 int dpm_suspend_noirq(pm_message_t state)
1136 {
1137         ktime_t starttime = ktime_get();
1138         int error = 0;
1139
1140         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1141         cpuidle_pause();
1142         device_wakeup_arm_wake_irqs();
1143         suspend_device_irqs();
1144         mutex_lock(&dpm_list_mtx);
1145         pm_transition = state;
1146         async_error = 0;
1147
1148         while (!list_empty(&dpm_late_early_list)) {
1149                 struct device *dev = to_device(dpm_late_early_list.prev);
1150
1151                 get_device(dev);
1152                 mutex_unlock(&dpm_list_mtx);
1153
1154                 error = device_suspend_noirq(dev);
1155
1156                 mutex_lock(&dpm_list_mtx);
1157                 if (error) {
1158                         pm_dev_err(dev, state, " noirq", error);
1159                         dpm_save_failed_dev(dev_name(dev));
1160                         put_device(dev);
1161                         break;
1162                 }
1163                 if (!list_empty(&dev->power.entry))
1164                         list_move(&dev->power.entry, &dpm_noirq_list);
1165                 put_device(dev);
1166
1167                 if (async_error)
1168                         break;
1169         }
1170         mutex_unlock(&dpm_list_mtx);
1171         async_synchronize_full();
1172         if (!error)
1173                 error = async_error;
1174
1175         if (error) {
1176                 suspend_stats.failed_suspend_noirq++;
1177                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1178                 dpm_resume_noirq(resume_event(state));
1179         } else {
1180                 dpm_show_time(starttime, state, "noirq");
1181         }
1182         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1183         return error;
1184 }
1185
1186 /**
1187  * device_suspend_late - Execute a "late suspend" callback for given device.
1188  * @dev: Device to handle.
1189  * @state: PM transition of the system being carried out.
1190  * @async: If true, the device is being suspended asynchronously.
1191  *
1192  * Runtime PM is disabled for @dev while this function is being executed.
1193  */
1194 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1195 {
1196         pm_callback_t callback = NULL;
1197         char *info = NULL;
1198         int error = 0;
1199
1200         TRACE_DEVICE(dev);
1201         TRACE_SUSPEND(0);
1202
1203         __pm_runtime_disable(dev, false);
1204
1205         if (async_error)
1206                 goto Complete;
1207
1208         if (pm_wakeup_pending()) {
1209                 async_error = -EBUSY;
1210                 goto Complete;
1211         }
1212
1213         if (dev->power.syscore || dev->power.direct_complete)
1214                 goto Complete;
1215
1216         dpm_wait_for_children(dev, async);
1217
1218         if (dev->pm_domain) {
1219                 info = "late power domain ";
1220                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1221         } else if (dev->type && dev->type->pm) {
1222                 info = "late type ";
1223                 callback = pm_late_early_op(dev->type->pm, state);
1224         } else if (dev->class && dev->class->pm) {
1225                 info = "late class ";
1226                 callback = pm_late_early_op(dev->class->pm, state);
1227         } else if (dev->bus && dev->bus->pm) {
1228                 info = "late bus ";
1229                 callback = pm_late_early_op(dev->bus->pm, state);
1230         }
1231
1232         if (!callback && dev->driver && dev->driver->pm) {
1233                 info = "late driver ";
1234                 callback = pm_late_early_op(dev->driver->pm, state);
1235         }
1236
1237         error = dpm_run_callback(callback, dev, state, info);
1238         if (!error)
1239                 dev->power.is_late_suspended = true;
1240         else
1241                 async_error = error;
1242
1243 Complete:
1244         TRACE_SUSPEND(error);
1245         complete_all(&dev->power.completion);
1246         return error;
1247 }
1248
1249 static void async_suspend_late(void *data, async_cookie_t cookie)
1250 {
1251         struct device *dev = (struct device *)data;
1252         int error;
1253
1254         error = __device_suspend_late(dev, pm_transition, true);
1255         if (error) {
1256                 dpm_save_failed_dev(dev_name(dev));
1257                 pm_dev_err(dev, pm_transition, " async", error);
1258         }
1259         put_device(dev);
1260 }
1261
1262 static int device_suspend_late(struct device *dev)
1263 {
1264         reinit_completion(&dev->power.completion);
1265
1266         if (is_async(dev)) {
1267                 get_device(dev);
1268                 async_schedule(async_suspend_late, dev);
1269                 return 0;
1270         }
1271
1272         return __device_suspend_late(dev, pm_transition, false);
1273 }
1274
1275 /**
1276  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1277  * @state: PM transition of the system being carried out.
1278  */
1279 int dpm_suspend_late(pm_message_t state)
1280 {
1281         ktime_t starttime = ktime_get();
1282         int error = 0;
1283
1284         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1285         mutex_lock(&dpm_list_mtx);
1286         pm_transition = state;
1287         async_error = 0;
1288
1289         while (!list_empty(&dpm_suspended_list)) {
1290                 struct device *dev = to_device(dpm_suspended_list.prev);
1291
1292                 get_device(dev);
1293                 mutex_unlock(&dpm_list_mtx);
1294
1295                 error = device_suspend_late(dev);
1296
1297                 mutex_lock(&dpm_list_mtx);
1298                 if (error) {
1299                         pm_dev_err(dev, state, " late", error);
1300                         dpm_save_failed_dev(dev_name(dev));
1301                         put_device(dev);
1302                         break;
1303                 }
1304                 if (!list_empty(&dev->power.entry))
1305                         list_move(&dev->power.entry, &dpm_late_early_list);
1306                 put_device(dev);
1307
1308                 if (async_error)
1309                         break;
1310         }
1311         mutex_unlock(&dpm_list_mtx);
1312         async_synchronize_full();
1313         if (!error)
1314                 error = async_error;
1315         if (error) {
1316                 suspend_stats.failed_suspend_late++;
1317                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1318                 dpm_resume_early(resume_event(state));
1319         } else {
1320                 dpm_show_time(starttime, state, "late");
1321         }
1322         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1323         return error;
1324 }
1325
1326 /**
1327  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1328  * @state: PM transition of the system being carried out.
1329  */
1330 int dpm_suspend_end(pm_message_t state)
1331 {
1332         int error = dpm_suspend_late(state);
1333         if (error)
1334                 return error;
1335
1336         error = dpm_suspend_noirq(state);
1337         if (error) {
1338                 dpm_resume_early(resume_event(state));
1339                 return error;
1340         }
1341
1342         return 0;
1343 }
1344 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1345
1346 /**
1347  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1348  * @dev: Device to suspend.
1349  * @state: PM transition of the system being carried out.
1350  * @cb: Suspend callback to execute.
1351  * @info: string description of caller.
1352  */
1353 static int legacy_suspend(struct device *dev, pm_message_t state,
1354                           int (*cb)(struct device *dev, pm_message_t state),
1355                           char *info)
1356 {
1357         int error;
1358         ktime_t calltime;
1359
1360         calltime = initcall_debug_start(dev);
1361
1362         trace_device_pm_callback_start(dev, info, state.event);
1363         error = cb(dev, state);
1364         trace_device_pm_callback_end(dev, error);
1365         suspend_report_result(cb, error);
1366
1367         initcall_debug_report(dev, calltime, error, state, info);
1368
1369         return error;
1370 }
1371
1372 /**
1373  * device_suspend - Execute "suspend" callbacks for given device.
1374  * @dev: Device to handle.
1375  * @state: PM transition of the system being carried out.
1376  * @async: If true, the device is being suspended asynchronously.
1377  */
1378 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1379 {
1380         pm_callback_t callback = NULL;
1381         char *info = NULL;
1382         int error = 0;
1383         struct timer_list timer;
1384         struct dpm_drv_wd_data data;
1385         char suspend_abort[MAX_SUSPEND_ABORT_LEN];
1386         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1387
1388         TRACE_DEVICE(dev);
1389         TRACE_SUSPEND(0);
1390
1391         dpm_wait_for_children(dev, async);
1392
1393         if (async_error)
1394                 goto Complete;
1395
1396         /*
1397          * If a device configured to wake up the system from sleep states
1398          * has been suspended at run time and there's a resume request pending
1399          * for it, this is equivalent to the device signaling wakeup, so the
1400          * system suspend operation should be aborted.
1401          */
1402         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1403                 pm_wakeup_event(dev, 0);
1404
1405         if (pm_wakeup_pending()) {
1406                 pm_get_active_wakeup_sources(suspend_abort,
1407                         MAX_SUSPEND_ABORT_LEN);
1408                 log_suspend_abort_reason(suspend_abort);
1409                 async_error = -EBUSY;
1410                 goto Complete;
1411         }
1412
1413         if (dev->power.syscore)
1414                 goto Complete;
1415
1416         data.dev = dev;
1417         data.tsk = current;
1418         init_timer_on_stack(&timer);
1419         timer.expires = jiffies + HZ * 12;
1420         timer.function = dpm_drv_timeout;
1421         timer.data = (unsigned long)&data;
1422         add_timer(&timer);
1423
1424         if (dev->power.direct_complete) {
1425                 if (pm_runtime_status_suspended(dev)) {
1426                         pm_runtime_disable(dev);
1427                         if (pm_runtime_status_suspended(dev))
1428                                 goto Complete;
1429
1430                         pm_runtime_enable(dev);
1431                 }
1432                 dev->power.direct_complete = false;
1433         }
1434
1435         dpm_watchdog_set(&wd, dev);
1436         device_lock(dev);
1437
1438         if (dev->pm_domain) {
1439                 info = "power domain ";
1440                 callback = pm_op(&dev->pm_domain->ops, state);
1441                 goto Run;
1442         }
1443
1444         if (dev->type && dev->type->pm) {
1445                 info = "type ";
1446                 callback = pm_op(dev->type->pm, state);
1447                 goto Run;
1448         }
1449
1450         if (dev->class) {
1451                 if (dev->class->pm) {
1452                         info = "class ";
1453                         callback = pm_op(dev->class->pm, state);
1454                         goto Run;
1455                 } else if (dev->class->suspend) {
1456                         pm_dev_dbg(dev, state, "legacy class ");
1457                         error = legacy_suspend(dev, state, dev->class->suspend,
1458                                                 "legacy class ");
1459                         goto End;
1460                 }
1461         }
1462
1463         if (dev->bus) {
1464                 if (dev->bus->pm) {
1465                         info = "bus ";
1466                         callback = pm_op(dev->bus->pm, state);
1467                 } else if (dev->bus->suspend) {
1468                         pm_dev_dbg(dev, state, "legacy bus ");
1469                         error = legacy_suspend(dev, state, dev->bus->suspend,
1470                                                 "legacy bus ");
1471                         goto End;
1472                 }
1473         }
1474
1475  Run:
1476         if (!callback && dev->driver && dev->driver->pm) {
1477                 info = "driver ";
1478                 callback = pm_op(dev->driver->pm, state);
1479         }
1480
1481         error = dpm_run_callback(callback, dev, state, info);
1482
1483  End:
1484         if (!error) {
1485                 struct device *parent = dev->parent;
1486
1487                 dev->power.is_suspended = true;
1488                 if (parent) {
1489                         spin_lock_irq(&parent->power.lock);
1490
1491                         dev->parent->power.direct_complete = false;
1492                         if (dev->power.wakeup_path
1493                             && !dev->parent->power.ignore_children)
1494                                 dev->parent->power.wakeup_path = true;
1495
1496                         spin_unlock_irq(&parent->power.lock);
1497                 }
1498         }
1499
1500         device_unlock(dev);
1501         dpm_watchdog_clear(&wd);
1502
1503         del_timer_sync(&timer);
1504         destroy_timer_on_stack(&timer);
1505
1506  Complete:
1507         complete_all(&dev->power.completion);
1508         if (error)
1509                 async_error = error;
1510
1511         TRACE_SUSPEND(error);
1512         return error;
1513 }
1514
1515 static void async_suspend(void *data, async_cookie_t cookie)
1516 {
1517         struct device *dev = (struct device *)data;
1518         int error;
1519
1520         error = __device_suspend(dev, pm_transition, true);
1521         if (error) {
1522                 dpm_save_failed_dev(dev_name(dev));
1523                 pm_dev_err(dev, pm_transition, " async", error);
1524         }
1525
1526         put_device(dev);
1527 }
1528
1529 static int device_suspend(struct device *dev)
1530 {
1531         reinit_completion(&dev->power.completion);
1532
1533         if (is_async(dev)) {
1534                 get_device(dev);
1535                 async_schedule(async_suspend, dev);
1536                 return 0;
1537         }
1538
1539         return __device_suspend(dev, pm_transition, false);
1540 }
1541
1542 /**
1543  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1544  * @state: PM transition of the system being carried out.
1545  */
1546 int dpm_suspend(pm_message_t state)
1547 {
1548         ktime_t starttime = ktime_get();
1549         int error = 0;
1550
1551         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1552         might_sleep();
1553
1554         cpufreq_suspend();
1555
1556         mutex_lock(&dpm_list_mtx);
1557         pm_transition = state;
1558         async_error = 0;
1559         while (!list_empty(&dpm_prepared_list)) {
1560                 struct device *dev = to_device(dpm_prepared_list.prev);
1561
1562                 get_device(dev);
1563                 mutex_unlock(&dpm_list_mtx);
1564
1565                 error = device_suspend(dev);
1566
1567                 mutex_lock(&dpm_list_mtx);
1568                 if (error) {
1569                         pm_dev_err(dev, state, "", error);
1570                         dpm_save_failed_dev(dev_name(dev));
1571                         put_device(dev);
1572                         break;
1573                 }
1574                 if (!list_empty(&dev->power.entry))
1575                         list_move(&dev->power.entry, &dpm_suspended_list);
1576                 put_device(dev);
1577                 if (async_error)
1578                         break;
1579         }
1580         mutex_unlock(&dpm_list_mtx);
1581         async_synchronize_full();
1582         if (!error)
1583                 error = async_error;
1584         if (error) {
1585                 suspend_stats.failed_suspend++;
1586                 dpm_save_failed_step(SUSPEND_SUSPEND);
1587         } else
1588                 dpm_show_time(starttime, state, NULL);
1589         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1590         return error;
1591 }
1592
1593 /**
1594  * device_prepare - Prepare a device for system power transition.
1595  * @dev: Device to handle.
1596  * @state: PM transition of the system being carried out.
1597  *
1598  * Execute the ->prepare() callback(s) for given device.  No new children of the
1599  * device may be registered after this function has returned.
1600  */
1601 static int device_prepare(struct device *dev, pm_message_t state)
1602 {
1603         int (*callback)(struct device *) = NULL;
1604         char *info = NULL;
1605         int ret = 0;
1606
1607         if (dev->power.syscore)
1608                 return 0;
1609
1610         /*
1611          * If a device's parent goes into runtime suspend at the wrong time,
1612          * it won't be possible to resume the device.  To prevent this we
1613          * block runtime suspend here, during the prepare phase, and allow
1614          * it again during the complete phase.
1615          */
1616         pm_runtime_get_noresume(dev);
1617
1618         device_lock(dev);
1619
1620         dev->power.wakeup_path = device_may_wakeup(dev);
1621
1622         if (dev->pm_domain) {
1623                 info = "preparing power domain ";
1624                 callback = dev->pm_domain->ops.prepare;
1625         } else if (dev->type && dev->type->pm) {
1626                 info = "preparing type ";
1627                 callback = dev->type->pm->prepare;
1628         } else if (dev->class && dev->class->pm) {
1629                 info = "preparing class ";
1630                 callback = dev->class->pm->prepare;
1631         } else if (dev->bus && dev->bus->pm) {
1632                 info = "preparing bus ";
1633                 callback = dev->bus->pm->prepare;
1634         }
1635
1636         if (!callback && dev->driver && dev->driver->pm) {
1637                 info = "preparing driver ";
1638                 callback = dev->driver->pm->prepare;
1639         }
1640
1641         if (callback)
1642                 ret = callback(dev);
1643
1644         device_unlock(dev);
1645
1646         if (ret < 0) {
1647                 suspend_report_result(callback, ret);
1648                 pm_runtime_put(dev);
1649                 return ret;
1650         }
1651         /*
1652          * A positive return value from ->prepare() means "this device appears
1653          * to be runtime-suspended and its state is fine, so if it really is
1654          * runtime-suspended, you can leave it in that state provided that you
1655          * will do the same thing with all of its descendants".  This only
1656          * applies to suspend transitions, however.
1657          */
1658         spin_lock_irq(&dev->power.lock);
1659         dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND;
1660         spin_unlock_irq(&dev->power.lock);
1661         return 0;
1662 }
1663
1664 /**
1665  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1666  * @state: PM transition of the system being carried out.
1667  *
1668  * Execute the ->prepare() callback(s) for all devices.
1669  */
1670 int dpm_prepare(pm_message_t state)
1671 {
1672         int error = 0;
1673
1674         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1675         might_sleep();
1676
1677         mutex_lock(&dpm_list_mtx);
1678         while (!list_empty(&dpm_list)) {
1679                 struct device *dev = to_device(dpm_list.next);
1680
1681                 get_device(dev);
1682                 mutex_unlock(&dpm_list_mtx);
1683
1684                 trace_device_pm_callback_start(dev, "", state.event);
1685                 error = device_prepare(dev, state);
1686                 trace_device_pm_callback_end(dev, error);
1687
1688                 mutex_lock(&dpm_list_mtx);
1689                 if (error) {
1690                         if (error == -EAGAIN) {
1691                                 put_device(dev);
1692                                 error = 0;
1693                                 continue;
1694                         }
1695                         printk(KERN_INFO "PM: Device %s not prepared "
1696                                 "for power transition: code %d\n",
1697                                 dev_name(dev), error);
1698                         put_device(dev);
1699                         break;
1700                 }
1701                 dev->power.is_prepared = true;
1702                 if (!list_empty(&dev->power.entry))
1703                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1704                 put_device(dev);
1705         }
1706         mutex_unlock(&dpm_list_mtx);
1707         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1708         return error;
1709 }
1710
1711 /**
1712  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1713  * @state: PM transition of the system being carried out.
1714  *
1715  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1716  * callbacks for them.
1717  */
1718 int dpm_suspend_start(pm_message_t state)
1719 {
1720         int error;
1721
1722         error = dpm_prepare(state);
1723         if (error) {
1724                 suspend_stats.failed_prepare++;
1725                 dpm_save_failed_step(SUSPEND_PREPARE);
1726         } else
1727                 error = dpm_suspend(state);
1728         return error;
1729 }
1730 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1731
1732 void __suspend_report_result(const char *function, void *fn, int ret)
1733 {
1734         if (ret)
1735                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1736 }
1737 EXPORT_SYMBOL_GPL(__suspend_report_result);
1738
1739 /**
1740  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1741  * @dev: Device to wait for.
1742  * @subordinate: Device that needs to wait for @dev.
1743  */
1744 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1745 {
1746         dpm_wait(dev, subordinate->power.async_suspend);
1747         return async_error;
1748 }
1749 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1750
1751 /**
1752  * dpm_for_each_dev - device iterator.
1753  * @data: data for the callback.
1754  * @fn: function to be called for each device.
1755  *
1756  * Iterate over devices in dpm_list, and call @fn for each device,
1757  * passing it @data.
1758  */
1759 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1760 {
1761         struct device *dev;
1762
1763         if (!fn)
1764                 return;
1765
1766         device_pm_lock();
1767         list_for_each_entry(dev, &dpm_list, power.entry)
1768                 fn(dev, data);
1769         device_pm_unlock();
1770 }
1771 EXPORT_SYMBOL_GPL(dpm_for_each_dev);