drivers/base/power/main.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
pm_verb
device_pm_sleep_init
device_pm_lock
device_pm_unlock
device_pm_add
device_pm_remove
device_pm_move_before
device_pm_move_after
device_pm_move_last
initcall_debug_start
initcall_debug_report
dpm_wait
dpm_wait_fn
dpm_wait_for_children
dpm_wait_for_suppliers
dpm_wait_for_superior
dpm_wait_for_consumers
dpm_wait_for_subordinate
pm_op
pm_late_early_op
pm_noirq_op
pm_dev_dbg
pm_dev_err
dpm_show_time
dpm_run_callback
dpm_watchdog_handler
dpm_watchdog_set
dpm_watchdog_clear
suspend_event
dev_pm_may_skip_resume
dpm_subsys_resume_noirq_cb
device_resume_noirq
is_async
dpm_async_fn
async_resume_noirq
dpm_noirq_resume_devices
dpm_resume_noirq
dpm_subsys_resume_early_cb
device_resume_early
async_resume_early
dpm_resume_early
dpm_resume_start
device_resume
async_resume
dpm_resume
device_complete
dpm_complete
dpm_resume_end
resume_event
dpm_superior_set_must_resume
dpm_subsys_suspend_noirq_cb
device_must_resume
__device_suspend_noirq
async_suspend_noirq
device_suspend_noirq
dpm_noirq_suspend_devices
dpm_suspend_noirq
dpm_propagate_wakeup_to_parent
dpm_subsys_suspend_late_cb
__device_suspend_late
async_suspend_late
device_suspend_late
dpm_suspend_late
dpm_suspend_end
legacy_suspend
dpm_clear_superiors_direct_complete
__device_suspend
async_suspend
device_suspend
dpm_suspend
device_prepare
dpm_prepare
dpm_suspend_start
__suspend_report_result
device_pm_wait_for_dev
dpm_for_each_dev
pm_ops_is_empty
device_pm_check_callbacks
dev_pm_smart_suspend_and_suspended
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/base/power/main.c - Where the driver meets power management.
   4  *
   5  * Copyright (c) 2003 Patrick Mochel
   6  * Copyright (c) 2003 Open Source Development Lab
   7  *
   8  * The driver model core calls device_pm_add() when a device is registered.
   9  * This will initialize the embedded device_pm_info object in the device
  10  * and add it to the list of power-controlled devices. sysfs entries for
  11  * controlling device power management will also be added.
  12  *
  13  * A separate list is used for keeping track of power info, because the power
  14  * domain dependencies may differ from the ancestral dependencies that the
  15  * subsystem list maintains.
  16  */
  17 
  18 #define pr_fmt(fmt) "PM: " fmt
  19 
  20 #include <linux/device.h>
  21 #include <linux/export.h>
  22 #include <linux/mutex.h>
  23 #include <linux/pm.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/pm-trace.h>
  26 #include <linux/pm_wakeirq.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/sched.h>
  29 #include <linux/sched/debug.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/devfreq.h>
  36 #include <linux/timer.h>
  37 
  38 #include "../base.h"
  39 #include "power.h"
  40 
  41 typedef int (*pm_callback_t)(struct device *);
  42 
  43 /*
  44  * The entries in the dpm_list list are in a depth first order, simply
  45  * because children are guaranteed to be discovered after parents, and
  46  * are inserted at the back of the list on discovery.
  47  *
  48  * Since device_pm_add() may be called with a device lock held,
  49  * we must never try to acquire a device lock while holding
  50  * dpm_list_mutex.
  51  */
  52 
  53 LIST_HEAD(dpm_list);
  54 static LIST_HEAD(dpm_prepared_list);
  55 static LIST_HEAD(dpm_suspended_list);
  56 static LIST_HEAD(dpm_late_early_list);
  57 static LIST_HEAD(dpm_noirq_list);
  58 
  59 struct suspend_stats suspend_stats;
  60 static DEFINE_MUTEX(dpm_list_mtx);
  61 static pm_message_t pm_transition;
  62 
  63 static int async_error;
  64 
  65 static const char *pm_verb(int event)
  66 {
  67         switch (event) {
  68         case PM_EVENT_SUSPEND:
  69                 return "suspend";
  70         case PM_EVENT_RESUME:
  71                 return "resume";
  72         case PM_EVENT_FREEZE:
  73                 return "freeze";
  74         case PM_EVENT_QUIESCE:
  75                 return "quiesce";
  76         case PM_EVENT_HIBERNATE:
  77                 return "hibernate";
  78         case PM_EVENT_THAW:
  79                 return "thaw";
  80         case PM_EVENT_RESTORE:
  81                 return "restore";
  82         case PM_EVENT_RECOVER:
  83                 return "recover";
  84         default:
  85                 return "(unknown PM event)";
  86         }
  87 }
  88 
  89 /**
  90  * device_pm_sleep_init - Initialize system suspend-related device fields.
  91  * @dev: Device object being initialized.
  92  */
  93 void device_pm_sleep_init(struct device *dev)
  94 {
  95         dev->power.is_prepared = false;
  96         dev->power.is_suspended = false;
  97         dev->power.is_noirq_suspended = false;
  98         dev->power.is_late_suspended = false;
  99         init_completion(&dev->power.completion);
 100         complete_all(&dev->power.completion);
 101         dev->power.wakeup = NULL;
 102         INIT_LIST_HEAD(&dev->power.entry);
 103 }
 104 
 105 /**
 106  * device_pm_lock - Lock the list of active devices used by the PM core.
 107  */
 108 void device_pm_lock(void)
 109 {
 110         mutex_lock(&dpm_list_mtx);
 111 }
 112 
 113 /**
 114  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 115  */
 116 void device_pm_unlock(void)
 117 {
 118         mutex_unlock(&dpm_list_mtx);
 119 }
 120 
 121 /**
 122  * device_pm_add - Add a device to the PM core's list of active devices.
 123  * @dev: Device to add to the list.
 124  */
 125 void device_pm_add(struct device *dev)
 126 {
 127         /* Skip PM setup/initialization. */
 128         if (device_pm_not_required(dev))
 129                 return;
 130 
 131         pr_debug("Adding info for %s:%s\n",
 132                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 133         device_pm_check_callbacks(dev);
 134         mutex_lock(&dpm_list_mtx);
 135         if (dev->parent && dev->parent->power.is_prepared)
 136                 dev_warn(dev, "parent %s should not be sleeping\n",
 137                         dev_name(dev->parent));
 138         list_add_tail(&dev->power.entry, &dpm_list);
 139         dev->power.in_dpm_list = true;
 140         mutex_unlock(&dpm_list_mtx);
 141 }
 142 
 143 /**
 144  * device_pm_remove - Remove a device from the PM core's list of active devices.
 145  * @dev: Device to be removed from the list.
 146  */
 147 void device_pm_remove(struct device *dev)
 148 {
 149         if (device_pm_not_required(dev))
 150                 return;
 151 
 152         pr_debug("Removing info for %s:%s\n",
 153                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 154         complete_all(&dev->power.completion);
 155         mutex_lock(&dpm_list_mtx);
 156         list_del_init(&dev->power.entry);
 157         dev->power.in_dpm_list = false;
 158         mutex_unlock(&dpm_list_mtx);
 159         device_wakeup_disable(dev);
 160         pm_runtime_remove(dev);
 161         device_pm_check_callbacks(dev);
 162 }
 163 
 164 /**
 165  * device_pm_move_before - Move device in the PM core's list of active devices.
 166  * @deva: Device to move in dpm_list.
 167  * @devb: Device @deva should come before.
 168  */
 169 void device_pm_move_before(struct device *deva, struct device *devb)
 170 {
 171         pr_debug("Moving %s:%s before %s:%s\n",
 172                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 173                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 174         /* Delete deva from dpm_list and reinsert before devb. */
 175         list_move_tail(&deva->power.entry, &devb->power.entry);
 176 }
 177 
 178 /**
 179  * device_pm_move_after - Move device in the PM core's list of active devices.
 180  * @deva: Device to move in dpm_list.
 181  * @devb: Device @deva should come after.
 182  */
 183 void device_pm_move_after(struct device *deva, struct device *devb)
 184 {
 185         pr_debug("Moving %s:%s after %s:%s\n",
 186                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 187                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 188         /* Delete deva from dpm_list and reinsert after devb. */
 189         list_move(&deva->power.entry, &devb->power.entry);
 190 }
 191 
 192 /**
 193  * device_pm_move_last - Move device to end of the PM core's list of devices.
 194  * @dev: Device to move in dpm_list.
 195  */
 196 void device_pm_move_last(struct device *dev)
 197 {
 198         pr_debug("Moving %s:%s to end of list\n",
 199                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 200         list_move_tail(&dev->power.entry, &dpm_list);
 201 }
 202 
 203 static ktime_t initcall_debug_start(struct device *dev, void *cb)
 204 {
 205         if (!pm_print_times_enabled)
 206                 return 0;
 207 
 208         dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
 209                  task_pid_nr(current),
 210                  dev->parent ? dev_name(dev->parent) : "none");
 211         return ktime_get();
 212 }
 213 
 214 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 215                                   void *cb, int error)
 216 {
 217         ktime_t rettime;
 218         s64 nsecs;
 219 
 220         if (!pm_print_times_enabled)
 221                 return;
 222 
 223         rettime = ktime_get();
 224         nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 225 
 226         dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
 227                  (unsigned long long)nsecs >> 10);
 228 }
 229 
 230 /**
 231  * dpm_wait - Wait for a PM operation to complete.
 232  * @dev: Device to wait for.
 233  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 234  */
 235 static void dpm_wait(struct device *dev, bool async)
 236 {
 237         if (!dev)
 238                 return;
 239 
 240         if (async || (pm_async_enabled && dev->power.async_suspend))
 241                 wait_for_completion(&dev->power.completion);
 242 }
 243 
 244 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 245 {
 246         dpm_wait(dev, *((bool *)async_ptr));
 247         return 0;
 248 }
 249 
 250 static void dpm_wait_for_children(struct device *dev, bool async)
 251 {
 252        device_for_each_child(dev, &async, dpm_wait_fn);
 253 }
 254 
 255 static void dpm_wait_for_suppliers(struct device *dev, bool async)
 256 {
 257         struct device_link *link;
 258         int idx;
 259 
 260         idx = device_links_read_lock();
 261 
 262         /*
 263          * If the supplier goes away right after we've checked the link to it,
 264          * we'll wait for its completion to change the state, but that's fine,
 265          * because the only things that will block as a result are the SRCU
 266          * callbacks freeing the link objects for the links in the list we're
 267          * walking.
 268          */
 269         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
 270                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 271                         dpm_wait(link->supplier, async);
 272 
 273         device_links_read_unlock(idx);
 274 }
 275 
 276 static bool dpm_wait_for_superior(struct device *dev, bool async)
 277 {
 278         struct device *parent;
 279 
 280         /*
 281          * If the device is resumed asynchronously and the parent's callback
 282          * deletes both the device and the parent itself, the parent object may
 283          * be freed while this function is running, so avoid that by reference
 284          * counting the parent once more unless the device has been deleted
 285          * already (in which case return right away).
 286          */
 287         mutex_lock(&dpm_list_mtx);
 288 
 289         if (!device_pm_initialized(dev)) {
 290                 mutex_unlock(&dpm_list_mtx);
 291                 return false;
 292         }
 293 
 294         parent = get_device(dev->parent);
 295 
 296         mutex_unlock(&dpm_list_mtx);
 297 
 298         dpm_wait(parent, async);
 299         put_device(parent);
 300 
 301         dpm_wait_for_suppliers(dev, async);
 302 
 303         /*
 304          * If the parent's callback has deleted the device, attempting to resume
 305          * it would be invalid, so avoid doing that then.
 306          */
 307         return device_pm_initialized(dev);
 308 }
 309 
 310 static void dpm_wait_for_consumers(struct device *dev, bool async)
 311 {
 312         struct device_link *link;
 313         int idx;
 314 
 315         idx = device_links_read_lock();
 316 
 317         /*
 318          * The status of a device link can only be changed from "dormant" by a
 319          * probe, but that cannot happen during system suspend/resume.  In
 320          * theory it can change to "dormant" at that time, but then it is
 321          * reasonable to wait for the target device anyway (eg. if it goes
 322          * away, it's better to wait for it to go away completely and then
 323          * continue instead of trying to continue in parallel with its
 324          * unregistration).
 325          */
 326         list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
 327                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 328                         dpm_wait(link->consumer, async);
 329 
 330         device_links_read_unlock(idx);
 331 }
 332 
 333 static void dpm_wait_for_subordinate(struct device *dev, bool async)
 334 {
 335         dpm_wait_for_children(dev, async);
 336         dpm_wait_for_consumers(dev, async);
 337 }
 338 
 339 /**
 340  * pm_op - Return the PM operation appropriate for given PM event.
 341  * @ops: PM operations to choose from.
 342  * @state: PM transition of the system being carried out.
 343  */
 344 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 345 {
 346         switch (state.event) {
 347 #ifdef CONFIG_SUSPEND
 348         case PM_EVENT_SUSPEND:
 349                 return ops->suspend;
 350         case PM_EVENT_RESUME:
 351                 return ops->resume;
 352 #endif /* CONFIG_SUSPEND */
 353 #ifdef CONFIG_HIBERNATE_CALLBACKS
 354         case PM_EVENT_FREEZE:
 355         case PM_EVENT_QUIESCE:
 356                 return ops->freeze;
 357         case PM_EVENT_HIBERNATE:
 358                 return ops->poweroff;
 359         case PM_EVENT_THAW:
 360         case PM_EVENT_RECOVER:
 361                 return ops->thaw;
 362                 break;
 363         case PM_EVENT_RESTORE:
 364                 return ops->restore;
 365 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 366         }
 367 
 368         return NULL;
 369 }
 370 
 371 /**
 372  * pm_late_early_op - Return the PM operation appropriate for given PM event.
 373  * @ops: PM operations to choose from.
 374  * @state: PM transition of the system being carried out.
 375  *
 376  * Runtime PM is disabled for @dev while this function is being executed.
 377  */
 378 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 379                                       pm_message_t state)
 380 {
 381         switch (state.event) {
 382 #ifdef CONFIG_SUSPEND
 383         case PM_EVENT_SUSPEND:
 384                 return ops->suspend_late;
 385         case PM_EVENT_RESUME:
 386                 return ops->resume_early;
 387 #endif /* CONFIG_SUSPEND */
 388 #ifdef CONFIG_HIBERNATE_CALLBACKS
 389         case PM_EVENT_FREEZE:
 390         case PM_EVENT_QUIESCE:
 391                 return ops->freeze_late;
 392         case PM_EVENT_HIBERNATE:
 393                 return ops->poweroff_late;
 394         case PM_EVENT_THAW:
 395         case PM_EVENT_RECOVER:
 396                 return ops->thaw_early;
 397         case PM_EVENT_RESTORE:
 398                 return ops->restore_early;
 399 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 400         }
 401 
 402         return NULL;
 403 }
 404 
 405 /**
 406  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 407  * @ops: PM operations to choose from.
 408  * @state: PM transition of the system being carried out.
 409  *
 410  * The driver of @dev will not receive interrupts while this function is being
 411  * executed.
 412  */
 413 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 414 {
 415         switch (state.event) {
 416 #ifdef CONFIG_SUSPEND
 417         case PM_EVENT_SUSPEND:
 418                 return ops->suspend_noirq;
 419         case PM_EVENT_RESUME:
 420                 return ops->resume_noirq;
 421 #endif /* CONFIG_SUSPEND */
 422 #ifdef CONFIG_HIBERNATE_CALLBACKS
 423         case PM_EVENT_FREEZE:
 424         case PM_EVENT_QUIESCE:
 425                 return ops->freeze_noirq;
 426         case PM_EVENT_HIBERNATE:
 427                 return ops->poweroff_noirq;
 428         case PM_EVENT_THAW:
 429         case PM_EVENT_RECOVER:
 430                 return ops->thaw_noirq;
 431         case PM_EVENT_RESTORE:
 432                 return ops->restore_noirq;
 433 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 434         }
 435 
 436         return NULL;
 437 }
 438 
 439 static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
 440 {
 441         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 442                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 443                 ", may wakeup" : "");
 444 }
 445 
 446 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
 447                         int error)
 448 {
 449         pr_err("Device %s failed to %s%s: error %d\n",
 450                dev_name(dev), pm_verb(state.event), info, error);
 451 }
 452 
 453 static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
 454                           const char *info)
 455 {
 456         ktime_t calltime;
 457         u64 usecs64;
 458         int usecs;
 459 
 460         calltime = ktime_get();
 461         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 462         do_div(usecs64, NSEC_PER_USEC);
 463         usecs = usecs64;
 464         if (usecs == 0)
 465                 usecs = 1;
 466 
 467         pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
 468                   info ?: "", info ? " " : "", pm_verb(state.event),
 469                   error ? "aborted" : "complete",
 470                   usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 471 }
 472 
 473 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 474                             pm_message_t state, const char *info)
 475 {
 476         ktime_t calltime;
 477         int error;
 478 
 479         if (!cb)
 480                 return 0;
 481 
 482         calltime = initcall_debug_start(dev, cb);
 483 
 484         pm_dev_dbg(dev, state, info);
 485         trace_device_pm_callback_start(dev, info, state.event);
 486         error = cb(dev);
 487         trace_device_pm_callback_end(dev, error);
 488         suspend_report_result(cb, error);
 489 
 490         initcall_debug_report(dev, calltime, cb, error);
 491 
 492         return error;
 493 }
 494 
 495 #ifdef CONFIG_DPM_WATCHDOG
 496 struct dpm_watchdog {
 497         struct device           *dev;
 498         struct task_struct      *tsk;
 499         struct timer_list       timer;
 500 };
 501 
 502 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 503         struct dpm_watchdog wd
 504 
 505 /**
 506  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 507  * @t: The timer that PM watchdog depends on.
 508  *
 509  * Called when a driver has timed out suspending or resuming.
 510  * There's not much we can do here to recover so panic() to
 511  * capture a crash-dump in pstore.
 512  */
 513 static void dpm_watchdog_handler(struct timer_list *t)
 514 {
 515         struct dpm_watchdog *wd = from_timer(wd, t, timer);
 516 
 517         dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 518         show_stack(wd->tsk, NULL);
 519         panic("%s %s: unrecoverable failure\n",
 520                 dev_driver_string(wd->dev), dev_name(wd->dev));
 521 }
 522 
 523 /**
 524  * dpm_watchdog_set - Enable pm watchdog for given device.
 525  * @wd: Watchdog. Must be allocated on the stack.
 526  * @dev: Device to handle.
 527  */
 528 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 529 {
 530         struct timer_list *timer = &wd->timer;
 531 
 532         wd->dev = dev;
 533         wd->tsk = current;
 534 
 535         timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
 536         /* use same timeout value for both suspend and resume */
 537         timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 538         add_timer(timer);
 539 }
 540 
 541 /**
 542  * dpm_watchdog_clear - Disable suspend/resume watchdog.
 543  * @wd: Watchdog to disable.
 544  */
 545 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 546 {
 547         struct timer_list *timer = &wd->timer;
 548 
 549         del_timer_sync(timer);
 550         destroy_timer_on_stack(timer);
 551 }
 552 #else
 553 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 554 #define dpm_watchdog_set(x, y)
 555 #define dpm_watchdog_clear(x)
 556 #endif
 557 
 558 /*------------------------- Resume routines -------------------------*/
 559 
 560 /**
 561  * suspend_event - Return a "suspend" message for given "resume" one.
 562  * @resume_msg: PM message representing a system-wide resume transition.
 563  */
 564 static pm_message_t suspend_event(pm_message_t resume_msg)
 565 {
 566         switch (resume_msg.event) {
 567         case PM_EVENT_RESUME:
 568                 return PMSG_SUSPEND;
 569         case PM_EVENT_THAW:
 570         case PM_EVENT_RESTORE:
 571                 return PMSG_FREEZE;
 572         case PM_EVENT_RECOVER:
 573                 return PMSG_HIBERNATE;
 574         }
 575         return PMSG_ON;
 576 }
 577 
 578 /**
 579  * dev_pm_may_skip_resume - System-wide device resume optimization check.
 580  * @dev: Target device.
 581  *
 582  * Checks whether or not the device may be left in suspend after a system-wide
 583  * transition to the working state.
 584  */
 585 bool dev_pm_may_skip_resume(struct device *dev)
 586 {
 587         return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
 588 }
 589 
 590 static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
 591                                                 pm_message_t state,
 592                                                 const char **info_p)
 593 {
 594         pm_callback_t callback;
 595         const char *info;
 596 
 597         if (dev->pm_domain) {
 598                 info = "noirq power domain ";
 599                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 600         } else if (dev->type && dev->type->pm) {
 601                 info = "noirq type ";
 602                 callback = pm_noirq_op(dev->type->pm, state);
 603         } else if (dev->class && dev->class->pm) {
 604                 info = "noirq class ";
 605                 callback = pm_noirq_op(dev->class->pm, state);
 606         } else if (dev->bus && dev->bus->pm) {
 607                 info = "noirq bus ";
 608                 callback = pm_noirq_op(dev->bus->pm, state);
 609         } else {
 610                 return NULL;
 611         }
 612 
 613         if (info_p)
 614                 *info_p = info;
 615 
 616         return callback;
 617 }
 618 
 619 static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
 620                                                  pm_message_t state,
 621                                                  const char **info_p);
 622 
 623 static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
 624                                                 pm_message_t state,
 625                                                 const char **info_p);
 626 
 627 /**
 628  * device_resume_noirq - Execute a "noirq resume" callback for given device.
 629  * @dev: Device to handle.
 630  * @state: PM transition of the system being carried out.
 631  * @async: If true, the device is being resumed asynchronously.
 632  *
 633  * The driver of @dev will not receive interrupts while this function is being
 634  * executed.
 635  */
 636 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 637 {
 638         pm_callback_t callback;
 639         const char *info;
 640         bool skip_resume;
 641         int error = 0;
 642 
 643         TRACE_DEVICE(dev);
 644         TRACE_RESUME(0);
 645 
 646         if (dev->power.syscore || dev->power.direct_complete)
 647                 goto Out;
 648 
 649         if (!dev->power.is_noirq_suspended)
 650                 goto Out;
 651 
 652         if (!dpm_wait_for_superior(dev, async))
 653                 goto Out;
 654 
 655         skip_resume = dev_pm_may_skip_resume(dev);
 656 
 657         callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
 658         if (callback)
 659                 goto Run;
 660 
 661         if (skip_resume)
 662                 goto Skip;
 663 
 664         if (dev_pm_smart_suspend_and_suspended(dev)) {
 665                 pm_message_t suspend_msg = suspend_event(state);
 666 
 667                 /*
 668                  * If "freeze" callbacks have been skipped during a transition
 669                  * related to hibernation, the subsequent "thaw" callbacks must
 670                  * be skipped too or bad things may happen.  Otherwise, resume
 671                  * callbacks are going to be run for the device, so its runtime
 672                  * PM status must be changed to reflect the new state after the
 673                  * transition under way.
 674                  */
 675                 if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
 676                     !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
 677                         if (state.event == PM_EVENT_THAW) {
 678                                 skip_resume = true;
 679                                 goto Skip;
 680                         } else {
 681                                 pm_runtime_set_active(dev);
 682                         }
 683                 }
 684         }
 685 
 686         if (dev->driver && dev->driver->pm) {
 687                 info = "noirq driver ";
 688                 callback = pm_noirq_op(dev->driver->pm, state);
 689         }
 690 
 691 Run:
 692         error = dpm_run_callback(callback, dev, state, info);
 693 
 694 Skip:
 695         dev->power.is_noirq_suspended = false;
 696 
 697         if (skip_resume) {
 698                 /* Make the next phases of resume skip the device. */
 699                 dev->power.is_late_suspended = false;
 700                 dev->power.is_suspended = false;
 701                 /*
 702                  * The device is going to be left in suspend, but it might not
 703                  * have been in runtime suspend before the system suspended, so
 704                  * its runtime PM status needs to be updated to avoid confusing
 705                  * the runtime PM framework when runtime PM is enabled for the
 706                  * device again.
 707                  */
 708                 pm_runtime_set_suspended(dev);
 709         }
 710 
 711 Out:
 712         complete_all(&dev->power.completion);
 713         TRACE_RESUME(error);
 714         return error;
 715 }
 716 
 717 static bool is_async(struct device *dev)
 718 {
 719         return dev->power.async_suspend && pm_async_enabled
 720                 && !pm_trace_is_enabled();
 721 }
 722 
 723 static bool dpm_async_fn(struct device *dev, async_func_t func)
 724 {
 725         reinit_completion(&dev->power.completion);
 726 
 727         if (is_async(dev)) {
 728                 get_device(dev);
 729                 async_schedule_dev(func, dev);
 730                 return true;
 731         }
 732 
 733         return false;
 734 }
 735 
 736 static void async_resume_noirq(void *data, async_cookie_t cookie)
 737 {
 738         struct device *dev = (struct device *)data;
 739         int error;
 740 
 741         error = device_resume_noirq(dev, pm_transition, true);
 742         if (error)
 743                 pm_dev_err(dev, pm_transition, " async", error);
 744 
 745         put_device(dev);
 746 }
 747 
 748 static void dpm_noirq_resume_devices(pm_message_t state)
 749 {
 750         struct device *dev;
 751         ktime_t starttime = ktime_get();
 752 
 753         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 754         mutex_lock(&dpm_list_mtx);
 755         pm_transition = state;
 756 
 757         /*
 758          * Advanced the async threads upfront,
 759          * in case the starting of async threads is
 760          * delayed by non-async resuming devices.
 761          */
 762         list_for_each_entry(dev, &dpm_noirq_list, power.entry)
 763                 dpm_async_fn(dev, async_resume_noirq);
 764 
 765         while (!list_empty(&dpm_noirq_list)) {
 766                 dev = to_device(dpm_noirq_list.next);
 767                 get_device(dev);
 768                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 769                 mutex_unlock(&dpm_list_mtx);
 770 
 771                 if (!is_async(dev)) {
 772                         int error;
 773 
 774                         error = device_resume_noirq(dev, state, false);
 775                         if (error) {
 776                                 suspend_stats.failed_resume_noirq++;
 777                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 778                                 dpm_save_failed_dev(dev_name(dev));
 779                                 pm_dev_err(dev, state, " noirq", error);
 780                         }
 781                 }
 782 
 783                 mutex_lock(&dpm_list_mtx);
 784                 put_device(dev);
 785         }
 786         mutex_unlock(&dpm_list_mtx);
 787         async_synchronize_full();
 788         dpm_show_time(starttime, state, 0, "noirq");
 789         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 790 }
 791 
 792 /**
 793  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 794  * @state: PM transition of the system being carried out.
 795  *
 796  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 797  * allow device drivers' interrupt handlers to be called.
 798  */
 799 void dpm_resume_noirq(pm_message_t state)
 800 {
 801         dpm_noirq_resume_devices(state);
 802 
 803         resume_device_irqs();
 804         device_wakeup_disarm_wake_irqs();
 805 
 806         cpuidle_resume();
 807 }
 808 
 809 static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev,
 810                                                 pm_message_t state,
 811                                                 const char **info_p)
 812 {
 813         pm_callback_t callback;
 814         const char *info;
 815 
 816         if (dev->pm_domain) {
 817                 info = "early power domain ";
 818                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 819         } else if (dev->type && dev->type->pm) {
 820                 info = "early type ";
 821                 callback = pm_late_early_op(dev->type->pm, state);
 822         } else if (dev->class && dev->class->pm) {
 823                 info = "early class ";
 824                 callback = pm_late_early_op(dev->class->pm, state);
 825         } else if (dev->bus && dev->bus->pm) {
 826                 info = "early bus ";
 827                 callback = pm_late_early_op(dev->bus->pm, state);
 828         } else {
 829                 return NULL;
 830         }
 831 
 832         if (info_p)
 833                 *info_p = info;
 834 
 835         return callback;
 836 }
 837 
 838 /**
 839  * device_resume_early - Execute an "early resume" callback for given device.
 840  * @dev: Device to handle.
 841  * @state: PM transition of the system being carried out.
 842  * @async: If true, the device is being resumed asynchronously.
 843  *
 844  * Runtime PM is disabled for @dev while this function is being executed.
 845  */
 846 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 847 {
 848         pm_callback_t callback;
 849         const char *info;
 850         int error = 0;
 851 
 852         TRACE_DEVICE(dev);
 853         TRACE_RESUME(0);
 854 
 855         if (dev->power.syscore || dev->power.direct_complete)
 856                 goto Out;
 857 
 858         if (!dev->power.is_late_suspended)
 859                 goto Out;
 860 
 861         if (!dpm_wait_for_superior(dev, async))
 862                 goto Out;
 863 
 864         callback = dpm_subsys_resume_early_cb(dev, state, &info);
 865 
 866         if (!callback && dev->driver && dev->driver->pm) {
 867                 info = "early driver ";
 868                 callback = pm_late_early_op(dev->driver->pm, state);
 869         }
 870 
 871         error = dpm_run_callback(callback, dev, state, info);
 872         dev->power.is_late_suspended = false;
 873 
 874  Out:
 875         TRACE_RESUME(error);
 876 
 877         pm_runtime_enable(dev);
 878         complete_all(&dev->power.completion);
 879         return error;
 880 }
 881 
 882 static void async_resume_early(void *data, async_cookie_t cookie)
 883 {
 884         struct device *dev = (struct device *)data;
 885         int error;
 886 
 887         error = device_resume_early(dev, pm_transition, true);
 888         if (error)
 889                 pm_dev_err(dev, pm_transition, " async", error);
 890 
 891         put_device(dev);
 892 }
 893 
 894 /**
 895  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 896  * @state: PM transition of the system being carried out.
 897  */
 898 void dpm_resume_early(pm_message_t state)
 899 {
 900         struct device *dev;
 901         ktime_t starttime = ktime_get();
 902 
 903         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 904         mutex_lock(&dpm_list_mtx);
 905         pm_transition = state;
 906 
 907         /*
 908          * Advanced the async threads upfront,
 909          * in case the starting of async threads is
 910          * delayed by non-async resuming devices.
 911          */
 912         list_for_each_entry(dev, &dpm_late_early_list, power.entry)
 913                 dpm_async_fn(dev, async_resume_early);
 914 
 915         while (!list_empty(&dpm_late_early_list)) {
 916                 dev = to_device(dpm_late_early_list.next);
 917                 get_device(dev);
 918                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 919                 mutex_unlock(&dpm_list_mtx);
 920 
 921                 if (!is_async(dev)) {
 922                         int error;
 923 
 924                         error = device_resume_early(dev, state, false);
 925                         if (error) {
 926                                 suspend_stats.failed_resume_early++;
 927                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 928                                 dpm_save_failed_dev(dev_name(dev));
 929                                 pm_dev_err(dev, state, " early", error);
 930                         }
 931                 }
 932                 mutex_lock(&dpm_list_mtx);
 933                 put_device(dev);
 934         }
 935         mutex_unlock(&dpm_list_mtx);
 936         async_synchronize_full();
 937         dpm_show_time(starttime, state, 0, "early");
 938         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 939 }
 940 
 941 /**
 942  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 943  * @state: PM transition of the system being carried out.
 944  */
 945 void dpm_resume_start(pm_message_t state)
 946 {
 947         dpm_resume_noirq(state);
 948         dpm_resume_early(state);
 949 }
 950 EXPORT_SYMBOL_GPL(dpm_resume_start);
 951 
 952 /**
 953  * device_resume - Execute "resume" callbacks for given device.
 954  * @dev: Device to handle.
 955  * @state: PM transition of the system being carried out.
 956  * @async: If true, the device is being resumed asynchronously.
 957  */
 958 static int device_resume(struct device *dev, pm_message_t state, bool async)
 959 {
 960         pm_callback_t callback = NULL;
 961         const char *info = NULL;
 962         int error = 0;
 963         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 964 
 965         TRACE_DEVICE(dev);
 966         TRACE_RESUME(0);
 967 
 968         if (dev->power.syscore)
 969                 goto Complete;
 970 
 971         if (dev->power.direct_complete) {
 972                 /* Match the pm_runtime_disable() in __device_suspend(). */
 973                 pm_runtime_enable(dev);
 974                 goto Complete;
 975         }
 976 
 977         if (!dpm_wait_for_superior(dev, async))
 978                 goto Complete;
 979 
 980         dpm_watchdog_set(&wd, dev);
 981         device_lock(dev);
 982 
 983         /*
 984          * This is a fib.  But we'll allow new children to be added below
 985          * a resumed device, even if the device hasn't been completed yet.
 986          */
 987         dev->power.is_prepared = false;
 988 
 989         if (!dev->power.is_suspended)
 990                 goto Unlock;
 991 
 992         if (dev->pm_domain) {
 993                 info = "power domain ";
 994                 callback = pm_op(&dev->pm_domain->ops, state);
 995                 goto Driver;
 996         }
 997 
 998         if (dev->type && dev->type->pm) {
 999                 info = "type ";
1000                 callback = pm_op(dev->type->pm, state);
1001                 goto Driver;
1002         }
1003 
1004         if (dev->class && dev->class->pm) {
1005                 info = "class ";
1006                 callback = pm_op(dev->class->pm, state);
1007                 goto Driver;
1008         }
1009 
1010         if (dev->bus) {
1011                 if (dev->bus->pm) {
1012                         info = "bus ";
1013                         callback = pm_op(dev->bus->pm, state);
1014                 } else if (dev->bus->resume) {
1015                         info = "legacy bus ";
1016                         callback = dev->bus->resume;
1017                         goto End;
1018                 }
1019         }
1020 
1021  Driver:
1022         if (!callback && dev->driver && dev->driver->pm) {
1023                 info = "driver ";
1024                 callback = pm_op(dev->driver->pm, state);
1025         }
1026 
1027  End:
1028         error = dpm_run_callback(callback, dev, state, info);
1029         dev->power.is_suspended = false;
1030 
1031  Unlock:
1032         device_unlock(dev);
1033         dpm_watchdog_clear(&wd);
1034 
1035  Complete:
1036         complete_all(&dev->power.completion);
1037 
1038         TRACE_RESUME(error);
1039 
1040         return error;
1041 }
1042 
1043 static void async_resume(void *data, async_cookie_t cookie)
1044 {
1045         struct device *dev = (struct device *)data;
1046         int error;
1047 
1048         error = device_resume(dev, pm_transition, true);
1049         if (error)
1050                 pm_dev_err(dev, pm_transition, " async", error);
1051         put_device(dev);
1052 }
1053 
1054 /**
1055  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1056  * @state: PM transition of the system being carried out.
1057  *
1058  * Execute the appropriate "resume" callback for all devices whose status
1059  * indicates that they are suspended.
1060  */
1061 void dpm_resume(pm_message_t state)
1062 {
1063         struct device *dev;
1064         ktime_t starttime = ktime_get();
1065 
1066         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1067         might_sleep();
1068 
1069         mutex_lock(&dpm_list_mtx);
1070         pm_transition = state;
1071         async_error = 0;
1072 
1073         list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1074                 dpm_async_fn(dev, async_resume);
1075 
1076         while (!list_empty(&dpm_suspended_list)) {
1077                 dev = to_device(dpm_suspended_list.next);
1078                 get_device(dev);
1079                 if (!is_async(dev)) {
1080                         int error;
1081 
1082                         mutex_unlock(&dpm_list_mtx);
1083 
1084                         error = device_resume(dev, state, false);
1085                         if (error) {
1086                                 suspend_stats.failed_resume++;
1087                                 dpm_save_failed_step(SUSPEND_RESUME);
1088                                 dpm_save_failed_dev(dev_name(dev));
1089                                 pm_dev_err(dev, state, "", error);
1090                         }
1091 
1092                         mutex_lock(&dpm_list_mtx);
1093                 }
1094                 if (!list_empty(&dev->power.entry))
1095                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1096                 put_device(dev);
1097         }
1098         mutex_unlock(&dpm_list_mtx);
1099         async_synchronize_full();
1100         dpm_show_time(starttime, state, 0, NULL);
1101 
1102         cpufreq_resume();
1103         devfreq_resume();
1104         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1105 }
1106 
1107 /**
1108  * device_complete - Complete a PM transition for given device.
1109  * @dev: Device to handle.
1110  * @state: PM transition of the system being carried out.
1111  */
1112 static void device_complete(struct device *dev, pm_message_t state)
1113 {
1114         void (*callback)(struct device *) = NULL;
1115         const char *info = NULL;
1116 
1117         if (dev->power.syscore)
1118                 return;
1119 
1120         device_lock(dev);
1121 
1122         if (dev->pm_domain) {
1123                 info = "completing power domain ";
1124                 callback = dev->pm_domain->ops.complete;
1125         } else if (dev->type && dev->type->pm) {
1126                 info = "completing type ";
1127                 callback = dev->type->pm->complete;
1128         } else if (dev->class && dev->class->pm) {
1129                 info = "completing class ";
1130                 callback = dev->class->pm->complete;
1131         } else if (dev->bus && dev->bus->pm) {
1132                 info = "completing bus ";
1133                 callback = dev->bus->pm->complete;
1134         }
1135 
1136         if (!callback && dev->driver && dev->driver->pm) {
1137                 info = "completing driver ";
1138                 callback = dev->driver->pm->complete;
1139         }
1140 
1141         if (callback) {
1142                 pm_dev_dbg(dev, state, info);
1143                 callback(dev);
1144         }
1145 
1146         device_unlock(dev);
1147 
1148         pm_runtime_put(dev);
1149 }
1150 
1151 /**
1152  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1153  * @state: PM transition of the system being carried out.
1154  *
1155  * Execute the ->complete() callbacks for all devices whose PM status is not
1156  * DPM_ON (this allows new devices to be registered).
1157  */
1158 void dpm_complete(pm_message_t state)
1159 {
1160         struct list_head list;
1161 
1162         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1163         might_sleep();
1164 
1165         INIT_LIST_HEAD(&list);
1166         mutex_lock(&dpm_list_mtx);
1167         while (!list_empty(&dpm_prepared_list)) {
1168                 struct device *dev = to_device(dpm_prepared_list.prev);
1169 
1170                 get_device(dev);
1171                 dev->power.is_prepared = false;
1172                 list_move(&dev->power.entry, &list);
1173                 mutex_unlock(&dpm_list_mtx);
1174 
1175                 trace_device_pm_callback_start(dev, "", state.event);
1176                 device_complete(dev, state);
1177                 trace_device_pm_callback_end(dev, 0);
1178 
1179                 mutex_lock(&dpm_list_mtx);
1180                 put_device(dev);
1181         }
1182         list_splice(&list, &dpm_list);
1183         mutex_unlock(&dpm_list_mtx);
1184 
1185         /* Allow device probing and trigger re-probing of deferred devices */
1186         device_unblock_probing();
1187         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1188 }
1189 
1190 /**
1191  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1192  * @state: PM transition of the system being carried out.
1193  *
1194  * Execute "resume" callbacks for all devices and complete the PM transition of
1195  * the system.
1196  */
1197 void dpm_resume_end(pm_message_t state)
1198 {
1199         dpm_resume(state);
1200         dpm_complete(state);
1201 }
1202 EXPORT_SYMBOL_GPL(dpm_resume_end);
1203 
1204 
1205 /*------------------------- Suspend routines -------------------------*/
1206 
1207 /**
1208  * resume_event - Return a "resume" message for given "suspend" sleep state.
1209  * @sleep_state: PM message representing a sleep state.
1210  *
1211  * Return a PM message representing the resume event corresponding to given
1212  * sleep state.
1213  */
1214 static pm_message_t resume_event(pm_message_t sleep_state)
1215 {
1216         switch (sleep_state.event) {
1217         case PM_EVENT_SUSPEND:
1218                 return PMSG_RESUME;
1219         case PM_EVENT_FREEZE:
1220         case PM_EVENT_QUIESCE:
1221                 return PMSG_RECOVER;
1222         case PM_EVENT_HIBERNATE:
1223                 return PMSG_RESTORE;
1224         }
1225         return PMSG_ON;
1226 }
1227 
1228 static void dpm_superior_set_must_resume(struct device *dev)
1229 {
1230         struct device_link *link;
1231         int idx;
1232 
1233         if (dev->parent)
1234                 dev->parent->power.must_resume = true;
1235 
1236         idx = device_links_read_lock();
1237 
1238         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
1239                 link->supplier->power.must_resume = true;
1240 
1241         device_links_read_unlock(idx);
1242 }
1243 
1244 static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
1245                                                  pm_message_t state,
1246                                                  const char **info_p)
1247 {
1248         pm_callback_t callback;
1249         const char *info;
1250 
1251         if (dev->pm_domain) {
1252                 info = "noirq power domain ";
1253                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1254         } else if (dev->type && dev->type->pm) {
1255                 info = "noirq type ";
1256                 callback = pm_noirq_op(dev->type->pm, state);
1257         } else if (dev->class && dev->class->pm) {
1258                 info = "noirq class ";
1259                 callback = pm_noirq_op(dev->class->pm, state);
1260         } else if (dev->bus && dev->bus->pm) {
1261                 info = "noirq bus ";
1262                 callback = pm_noirq_op(dev->bus->pm, state);
1263         } else {
1264                 return NULL;
1265         }
1266 
1267         if (info_p)
1268                 *info_p = info;
1269 
1270         return callback;
1271 }
1272 
1273 static bool device_must_resume(struct device *dev, pm_message_t state,
1274                                bool no_subsys_suspend_noirq)
1275 {
1276         pm_message_t resume_msg = resume_event(state);
1277 
1278         /*
1279          * If all of the device driver's "noirq", "late" and "early" callbacks
1280          * are invoked directly by the core, the decision to allow the device to
1281          * stay in suspend can be based on its current runtime PM status and its
1282          * wakeup settings.
1283          */
1284         if (no_subsys_suspend_noirq &&
1285             !dpm_subsys_suspend_late_cb(dev, state, NULL) &&
1286             !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) &&
1287             !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL))
1288                 return !pm_runtime_status_suspended(dev) &&
1289                         (resume_msg.event != PM_EVENT_RESUME ||
1290                          (device_can_wakeup(dev) && !device_may_wakeup(dev)));
1291 
1292         /*
1293          * The only safe strategy here is to require that if the device may not
1294          * be left in suspend, resume callbacks must be invoked for it.
1295          */
1296         return !dev->power.may_skip_resume;
1297 }
1298 
1299 /**
1300  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1301  * @dev: Device to handle.
1302  * @state: PM transition of the system being carried out.
1303  * @async: If true, the device is being suspended asynchronously.
1304  *
1305  * The driver of @dev will not receive interrupts while this function is being
1306  * executed.
1307  */
1308 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1309 {
1310         pm_callback_t callback;
1311         const char *info;
1312         bool no_subsys_cb = false;
1313         int error = 0;
1314 
1315         TRACE_DEVICE(dev);
1316         TRACE_SUSPEND(0);
1317 
1318         dpm_wait_for_subordinate(dev, async);
1319 
1320         if (async_error)
1321                 goto Complete;
1322 
1323         if (dev->power.syscore || dev->power.direct_complete)
1324                 goto Complete;
1325 
1326         callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
1327         if (callback)
1328                 goto Run;
1329 
1330         no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL);
1331 
1332         if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb)
1333                 goto Skip;
1334 
1335         if (dev->driver && dev->driver->pm) {
1336                 info = "noirq driver ";
1337                 callback = pm_noirq_op(dev->driver->pm, state);
1338         }
1339 
1340 Run:
1341         error = dpm_run_callback(callback, dev, state, info);
1342         if (error) {
1343                 async_error = error;
1344                 goto Complete;
1345         }
1346 
1347 Skip:
1348         dev->power.is_noirq_suspended = true;
1349 
1350         if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
1351                 dev->power.must_resume = dev->power.must_resume ||
1352                                 atomic_read(&dev->power.usage_count) > 1 ||
1353                                 device_must_resume(dev, state, no_subsys_cb);
1354         } else {
1355                 dev->power.must_resume = true;
1356         }
1357 
1358         if (dev->power.must_resume)
1359                 dpm_superior_set_must_resume(dev);
1360 
1361 Complete:
1362         complete_all(&dev->power.completion);
1363         TRACE_SUSPEND(error);
1364         return error;
1365 }
1366 
1367 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1368 {
1369         struct device *dev = (struct device *)data;
1370         int error;
1371 
1372         error = __device_suspend_noirq(dev, pm_transition, true);
1373         if (error) {
1374                 dpm_save_failed_dev(dev_name(dev));
1375                 pm_dev_err(dev, pm_transition, " async", error);
1376         }
1377 
1378         put_device(dev);
1379 }
1380 
1381 static int device_suspend_noirq(struct device *dev)
1382 {
1383         if (dpm_async_fn(dev, async_suspend_noirq))
1384                 return 0;
1385 
1386         return __device_suspend_noirq(dev, pm_transition, false);
1387 }
1388 
1389 static int dpm_noirq_suspend_devices(pm_message_t state)
1390 {
1391         ktime_t starttime = ktime_get();
1392         int error = 0;
1393 
1394         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1395         mutex_lock(&dpm_list_mtx);
1396         pm_transition = state;
1397         async_error = 0;
1398 
1399         while (!list_empty(&dpm_late_early_list)) {
1400                 struct device *dev = to_device(dpm_late_early_list.prev);
1401 
1402                 get_device(dev);
1403                 mutex_unlock(&dpm_list_mtx);
1404 
1405                 error = device_suspend_noirq(dev);
1406 
1407                 mutex_lock(&dpm_list_mtx);
1408                 if (error) {
1409                         pm_dev_err(dev, state, " noirq", error);
1410                         dpm_save_failed_dev(dev_name(dev));
1411                         put_device(dev);
1412                         break;
1413                 }
1414                 if (!list_empty(&dev->power.entry))
1415                         list_move(&dev->power.entry, &dpm_noirq_list);
1416                 put_device(dev);
1417 
1418                 if (async_error)
1419                         break;
1420         }
1421         mutex_unlock(&dpm_list_mtx);
1422         async_synchronize_full();
1423         if (!error)
1424                 error = async_error;
1425 
1426         if (error) {
1427                 suspend_stats.failed_suspend_noirq++;
1428                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1429         }
1430         dpm_show_time(starttime, state, error, "noirq");
1431         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1432         return error;
1433 }
1434 
1435 /**
1436  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1437  * @state: PM transition of the system being carried out.
1438  *
1439  * Prevent device drivers' interrupt handlers from being called and invoke
1440  * "noirq" suspend callbacks for all non-sysdev devices.
1441  */
1442 int dpm_suspend_noirq(pm_message_t state)
1443 {
1444         int ret;
1445 
1446         cpuidle_pause();
1447 
1448         device_wakeup_arm_wake_irqs();
1449         suspend_device_irqs();
1450 
1451         ret = dpm_noirq_suspend_devices(state);
1452         if (ret)
1453                 dpm_resume_noirq(resume_event(state));
1454 
1455         return ret;
1456 }
1457 
1458 static void dpm_propagate_wakeup_to_parent(struct device *dev)
1459 {
1460         struct device *parent = dev->parent;
1461 
1462         if (!parent)
1463                 return;
1464 
1465         spin_lock_irq(&parent->power.lock);
1466 
1467         if (dev->power.wakeup_path && !parent->power.ignore_children)
1468                 parent->power.wakeup_path = true;
1469 
1470         spin_unlock_irq(&parent->power.lock);
1471 }
1472 
1473 static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
1474                                                 pm_message_t state,
1475                                                 const char **info_p)
1476 {
1477         pm_callback_t callback;
1478         const char *info;
1479 
1480         if (dev->pm_domain) {
1481                 info = "late power domain ";
1482                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1483         } else if (dev->type && dev->type->pm) {
1484                 info = "late type ";
1485                 callback = pm_late_early_op(dev->type->pm, state);
1486         } else if (dev->class && dev->class->pm) {
1487                 info = "late class ";
1488                 callback = pm_late_early_op(dev->class->pm, state);
1489         } else if (dev->bus && dev->bus->pm) {
1490                 info = "late bus ";
1491                 callback = pm_late_early_op(dev->bus->pm, state);
1492         } else {
1493                 return NULL;
1494         }
1495 
1496         if (info_p)
1497                 *info_p = info;
1498 
1499         return callback;
1500 }
1501 
1502 /**
1503  * __device_suspend_late - Execute a "late suspend" callback for given device.
1504  * @dev: Device to handle.
1505  * @state: PM transition of the system being carried out.
1506  * @async: If true, the device is being suspended asynchronously.
1507  *
1508  * Runtime PM is disabled for @dev while this function is being executed.
1509  */
1510 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1511 {
1512         pm_callback_t callback;
1513         const char *info;
1514         int error = 0;
1515 
1516         TRACE_DEVICE(dev);
1517         TRACE_SUSPEND(0);
1518 
1519         __pm_runtime_disable(dev, false);
1520 
1521         dpm_wait_for_subordinate(dev, async);
1522 
1523         if (async_error)
1524                 goto Complete;
1525 
1526         if (pm_wakeup_pending()) {
1527                 async_error = -EBUSY;
1528                 goto Complete;
1529         }
1530 
1531         if (dev->power.syscore || dev->power.direct_complete)
1532                 goto Complete;
1533 
1534         callback = dpm_subsys_suspend_late_cb(dev, state, &info);
1535         if (callback)
1536                 goto Run;
1537 
1538         if (dev_pm_smart_suspend_and_suspended(dev) &&
1539             !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
1540                 goto Skip;
1541 
1542         if (dev->driver && dev->driver->pm) {
1543                 info = "late driver ";
1544                 callback = pm_late_early_op(dev->driver->pm, state);
1545         }
1546 
1547 Run:
1548         error = dpm_run_callback(callback, dev, state, info);
1549         if (error) {
1550                 async_error = error;
1551                 goto Complete;
1552         }
1553         dpm_propagate_wakeup_to_parent(dev);
1554 
1555 Skip:
1556         dev->power.is_late_suspended = true;
1557 
1558 Complete:
1559         TRACE_SUSPEND(error);
1560         complete_all(&dev->power.completion);
1561         return error;
1562 }
1563 
1564 static void async_suspend_late(void *data, async_cookie_t cookie)
1565 {
1566         struct device *dev = (struct device *)data;
1567         int error;
1568 
1569         error = __device_suspend_late(dev, pm_transition, true);
1570         if (error) {
1571                 dpm_save_failed_dev(dev_name(dev));
1572                 pm_dev_err(dev, pm_transition, " async", error);
1573         }
1574         put_device(dev);
1575 }
1576 
1577 static int device_suspend_late(struct device *dev)
1578 {
1579         if (dpm_async_fn(dev, async_suspend_late))
1580                 return 0;
1581 
1582         return __device_suspend_late(dev, pm_transition, false);
1583 }
1584 
1585 /**
1586  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1587  * @state: PM transition of the system being carried out.
1588  */
1589 int dpm_suspend_late(pm_message_t state)
1590 {
1591         ktime_t starttime = ktime_get();
1592         int error = 0;
1593 
1594         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1595         mutex_lock(&dpm_list_mtx);
1596         pm_transition = state;
1597         async_error = 0;
1598 
1599         while (!list_empty(&dpm_suspended_list)) {
1600                 struct device *dev = to_device(dpm_suspended_list.prev);
1601 
1602                 get_device(dev);
1603                 mutex_unlock(&dpm_list_mtx);
1604 
1605                 error = device_suspend_late(dev);
1606 
1607                 mutex_lock(&dpm_list_mtx);
1608                 if (!list_empty(&dev->power.entry))
1609                         list_move(&dev->power.entry, &dpm_late_early_list);
1610 
1611                 if (error) {
1612                         pm_dev_err(dev, state, " late", error);
1613                         dpm_save_failed_dev(dev_name(dev));
1614                         put_device(dev);
1615                         break;
1616                 }
1617                 put_device(dev);
1618 
1619                 if (async_error)
1620                         break;
1621         }
1622         mutex_unlock(&dpm_list_mtx);
1623         async_synchronize_full();
1624         if (!error)
1625                 error = async_error;
1626         if (error) {
1627                 suspend_stats.failed_suspend_late++;
1628                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1629                 dpm_resume_early(resume_event(state));
1630         }
1631         dpm_show_time(starttime, state, error, "late");
1632         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1633         return error;
1634 }
1635 
1636 /**
1637  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1638  * @state: PM transition of the system being carried out.
1639  */
1640 int dpm_suspend_end(pm_message_t state)
1641 {
1642         ktime_t starttime = ktime_get();
1643         int error;
1644 
1645         error = dpm_suspend_late(state);
1646         if (error)
1647                 goto out;
1648 
1649         error = dpm_suspend_noirq(state);
1650         if (error)
1651                 dpm_resume_early(resume_event(state));
1652 
1653 out:
1654         dpm_show_time(starttime, state, error, "end");
1655         return error;
1656 }
1657 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1658 
1659 /**
1660  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1661  * @dev: Device to suspend.
1662  * @state: PM transition of the system being carried out.
1663  * @cb: Suspend callback to execute.
1664  * @info: string description of caller.
1665  */
1666 static int legacy_suspend(struct device *dev, pm_message_t state,
1667                           int (*cb)(struct device *dev, pm_message_t state),
1668                           const char *info)
1669 {
1670         int error;
1671         ktime_t calltime;
1672 
1673         calltime = initcall_debug_start(dev, cb);
1674 
1675         trace_device_pm_callback_start(dev, info, state.event);
1676         error = cb(dev, state);
1677         trace_device_pm_callback_end(dev, error);
1678         suspend_report_result(cb, error);
1679 
1680         initcall_debug_report(dev, calltime, cb, error);
1681 
1682         return error;
1683 }
1684 
1685 static void dpm_clear_superiors_direct_complete(struct device *dev)
1686 {
1687         struct device_link *link;
1688         int idx;
1689 
1690         if (dev->parent) {
1691                 spin_lock_irq(&dev->parent->power.lock);
1692                 dev->parent->power.direct_complete = false;
1693                 spin_unlock_irq(&dev->parent->power.lock);
1694         }
1695 
1696         idx = device_links_read_lock();
1697 
1698         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1699                 spin_lock_irq(&link->supplier->power.lock);
1700                 link->supplier->power.direct_complete = false;
1701                 spin_unlock_irq(&link->supplier->power.lock);
1702         }
1703 
1704         device_links_read_unlock(idx);
1705 }
1706 
1707 /**
1708  * __device_suspend - Execute "suspend" callbacks for given device.
1709  * @dev: Device to handle.
1710  * @state: PM transition of the system being carried out.
1711  * @async: If true, the device is being suspended asynchronously.
1712  */
1713 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1714 {
1715         pm_callback_t callback = NULL;
1716         const char *info = NULL;
1717         int error = 0;
1718         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1719 
1720         TRACE_DEVICE(dev);
1721         TRACE_SUSPEND(0);
1722 
1723         dpm_wait_for_subordinate(dev, async);
1724 
1725         if (async_error) {
1726                 dev->power.direct_complete = false;
1727                 goto Complete;
1728         }
1729 
1730         /*
1731          * If a device configured to wake up the system from sleep states
1732          * has been suspended at run time and there's a resume request pending
1733          * for it, this is equivalent to the device signaling wakeup, so the
1734          * system suspend operation should be aborted.
1735          */
1736         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1737                 pm_wakeup_event(dev, 0);
1738 
1739         if (pm_wakeup_pending()) {
1740                 dev->power.direct_complete = false;
1741                 async_error = -EBUSY;
1742                 goto Complete;
1743         }
1744 
1745         if (dev->power.syscore)
1746                 goto Complete;
1747 
1748         /* Avoid direct_complete to let wakeup_path propagate. */
1749         if (device_may_wakeup(dev) || dev->power.wakeup_path)
1750                 dev->power.direct_complete = false;
1751 
1752         if (dev->power.direct_complete) {
1753                 if (pm_runtime_status_suspended(dev)) {
1754                         pm_runtime_disable(dev);
1755                         if (pm_runtime_status_suspended(dev)) {
1756                                 pm_dev_dbg(dev, state, "direct-complete ");
1757                                 goto Complete;
1758                         }
1759 
1760                         pm_runtime_enable(dev);
1761                 }
1762                 dev->power.direct_complete = false;
1763         }
1764 
1765         dev->power.may_skip_resume = false;
1766         dev->power.must_resume = false;
1767 
1768         dpm_watchdog_set(&wd, dev);
1769         device_lock(dev);
1770 
1771         if (dev->pm_domain) {
1772                 info = "power domain ";
1773                 callback = pm_op(&dev->pm_domain->ops, state);
1774                 goto Run;
1775         }
1776 
1777         if (dev->type && dev->type->pm) {
1778                 info = "type ";
1779                 callback = pm_op(dev->type->pm, state);
1780                 goto Run;
1781         }
1782 
1783         if (dev->class && dev->class->pm) {
1784                 info = "class ";
1785                 callback = pm_op(dev->class->pm, state);
1786                 goto Run;
1787         }
1788 
1789         if (dev->bus) {
1790                 if (dev->bus->pm) {
1791                         info = "bus ";
1792                         callback = pm_op(dev->bus->pm, state);
1793                 } else if (dev->bus->suspend) {
1794                         pm_dev_dbg(dev, state, "legacy bus ");
1795                         error = legacy_suspend(dev, state, dev->bus->suspend,
1796                                                 "legacy bus ");
1797                         goto End;
1798                 }
1799         }
1800 
1801  Run:
1802         if (!callback && dev->driver && dev->driver->pm) {
1803                 info = "driver ";
1804                 callback = pm_op(dev->driver->pm, state);
1805         }
1806 
1807         error = dpm_run_callback(callback, dev, state, info);
1808 
1809  End:
1810         if (!error) {
1811                 dev->power.is_suspended = true;
1812                 if (device_may_wakeup(dev))
1813                         dev->power.wakeup_path = true;
1814 
1815                 dpm_propagate_wakeup_to_parent(dev);
1816                 dpm_clear_superiors_direct_complete(dev);
1817         }
1818 
1819         device_unlock(dev);
1820         dpm_watchdog_clear(&wd);
1821 
1822  Complete:
1823         if (error)
1824                 async_error = error;
1825 
1826         complete_all(&dev->power.completion);
1827         TRACE_SUSPEND(error);
1828         return error;
1829 }
1830 
1831 static void async_suspend(void *data, async_cookie_t cookie)
1832 {
1833         struct device *dev = (struct device *)data;
1834         int error;
1835 
1836         error = __device_suspend(dev, pm_transition, true);
1837         if (error) {
1838                 dpm_save_failed_dev(dev_name(dev));
1839                 pm_dev_err(dev, pm_transition, " async", error);
1840         }
1841 
1842         put_device(dev);
1843 }
1844 
1845 static int device_suspend(struct device *dev)
1846 {
1847         if (dpm_async_fn(dev, async_suspend))
1848                 return 0;
1849 
1850         return __device_suspend(dev, pm_transition, false);
1851 }
1852 
1853 /**
1854  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1855  * @state: PM transition of the system being carried out.
1856  */
1857 int dpm_suspend(pm_message_t state)
1858 {
1859         ktime_t starttime = ktime_get();
1860         int error = 0;
1861 
1862         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1863         might_sleep();
1864 
1865         devfreq_suspend();
1866         cpufreq_suspend();
1867 
1868         mutex_lock(&dpm_list_mtx);
1869         pm_transition = state;
1870         async_error = 0;
1871         while (!list_empty(&dpm_prepared_list)) {
1872                 struct device *dev = to_device(dpm_prepared_list.prev);
1873 
1874                 get_device(dev);
1875                 mutex_unlock(&dpm_list_mtx);
1876 
1877                 error = device_suspend(dev);
1878 
1879                 mutex_lock(&dpm_list_mtx);
1880                 if (error) {
1881                         pm_dev_err(dev, state, "", error);
1882                         dpm_save_failed_dev(dev_name(dev));
1883                         put_device(dev);
1884                         break;
1885                 }
1886                 if (!list_empty(&dev->power.entry))
1887                         list_move(&dev->power.entry, &dpm_suspended_list);
1888                 put_device(dev);
1889                 if (async_error)
1890                         break;
1891         }
1892         mutex_unlock(&dpm_list_mtx);
1893         async_synchronize_full();
1894         if (!error)
1895                 error = async_error;
1896         if (error) {
1897                 suspend_stats.failed_suspend++;
1898                 dpm_save_failed_step(SUSPEND_SUSPEND);
1899         }
1900         dpm_show_time(starttime, state, error, NULL);
1901         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1902         return error;
1903 }
1904 
1905 /**
1906  * device_prepare - Prepare a device for system power transition.
1907  * @dev: Device to handle.
1908  * @state: PM transition of the system being carried out.
1909  *
1910  * Execute the ->prepare() callback(s) for given device.  No new children of the
1911  * device may be registered after this function has returned.
1912  */
1913 static int device_prepare(struct device *dev, pm_message_t state)
1914 {
1915         int (*callback)(struct device *) = NULL;
1916         int ret = 0;
1917 
1918         if (dev->power.syscore)
1919                 return 0;
1920 
1921         WARN_ON(!pm_runtime_enabled(dev) &&
1922                 dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
1923                                               DPM_FLAG_LEAVE_SUSPENDED));
1924 
1925         /*
1926          * If a device's parent goes into runtime suspend at the wrong time,
1927          * it won't be possible to resume the device.  To prevent this we
1928          * block runtime suspend here, during the prepare phase, and allow
1929          * it again during the complete phase.
1930          */
1931         pm_runtime_get_noresume(dev);
1932 
1933         device_lock(dev);
1934 
1935         dev->power.wakeup_path = false;
1936 
1937         if (dev->power.no_pm_callbacks)
1938                 goto unlock;
1939 
1940         if (dev->pm_domain)
1941                 callback = dev->pm_domain->ops.prepare;
1942         else if (dev->type && dev->type->pm)
1943                 callback = dev->type->pm->prepare;
1944         else if (dev->class && dev->class->pm)
1945                 callback = dev->class->pm->prepare;
1946         else if (dev->bus && dev->bus->pm)
1947                 callback = dev->bus->pm->prepare;
1948 
1949         if (!callback && dev->driver && dev->driver->pm)
1950                 callback = dev->driver->pm->prepare;
1951 
1952         if (callback)
1953                 ret = callback(dev);
1954 
1955 unlock:
1956         device_unlock(dev);
1957 
1958         if (ret < 0) {
1959                 suspend_report_result(callback, ret);
1960                 pm_runtime_put(dev);
1961                 return ret;
1962         }
1963         /*
1964          * A positive return value from ->prepare() means "this device appears
1965          * to be runtime-suspended and its state is fine, so if it really is
1966          * runtime-suspended, you can leave it in that state provided that you
1967          * will do the same thing with all of its descendants".  This only
1968          * applies to suspend transitions, however.
1969          */
1970         spin_lock_irq(&dev->power.lock);
1971         dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1972                 ((pm_runtime_suspended(dev) && ret > 0) ||
1973                  dev->power.no_pm_callbacks) &&
1974                 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1975         spin_unlock_irq(&dev->power.lock);
1976         return 0;
1977 }
1978 
1979 /**
1980  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1981  * @state: PM transition of the system being carried out.
1982  *
1983  * Execute the ->prepare() callback(s) for all devices.
1984  */
1985 int dpm_prepare(pm_message_t state)
1986 {
1987         int error = 0;
1988 
1989         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1990         might_sleep();
1991 
1992         /*
1993          * Give a chance for the known devices to complete their probes, before
1994          * disable probing of devices. This sync point is important at least
1995          * at boot time + hibernation restore.
1996          */
1997         wait_for_device_probe();
1998         /*
1999          * It is unsafe if probing of devices will happen during suspend or
2000          * hibernation and system behavior will be unpredictable in this case.
2001          * So, let's prohibit device's probing here and defer their probes
2002          * instead. The normal behavior will be restored in dpm_complete().
2003          */
2004         device_block_probing();
2005 
2006         mutex_lock(&dpm_list_mtx);
2007         while (!list_empty(&dpm_list)) {
2008                 struct device *dev = to_device(dpm_list.next);
2009 
2010                 get_device(dev);
2011                 mutex_unlock(&dpm_list_mtx);
2012 
2013                 trace_device_pm_callback_start(dev, "", state.event);
2014                 error = device_prepare(dev, state);
2015                 trace_device_pm_callback_end(dev, error);
2016 
2017                 mutex_lock(&dpm_list_mtx);
2018                 if (error) {
2019                         if (error == -EAGAIN) {
2020                                 put_device(dev);
2021                                 error = 0;
2022                                 continue;
2023                         }
2024                         pr_info("Device %s not prepared for power transition: code %d\n",
2025                                 dev_name(dev), error);
2026                         put_device(dev);
2027                         break;
2028                 }
2029                 dev->power.is_prepared = true;
2030                 if (!list_empty(&dev->power.entry))
2031                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
2032                 put_device(dev);
2033         }
2034         mutex_unlock(&dpm_list_mtx);
2035         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
2036         return error;
2037 }
2038 
2039 /**
2040  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
2041  * @state: PM transition of the system being carried out.
2042  *
2043  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
2044  * callbacks for them.
2045  */
2046 int dpm_suspend_start(pm_message_t state)
2047 {
2048         ktime_t starttime = ktime_get();
2049         int error;
2050 
2051         error = dpm_prepare(state);
2052         if (error) {
2053                 suspend_stats.failed_prepare++;
2054                 dpm_save_failed_step(SUSPEND_PREPARE);
2055         } else
2056                 error = dpm_suspend(state);
2057         dpm_show_time(starttime, state, error, "start");
2058         return error;
2059 }
2060 EXPORT_SYMBOL_GPL(dpm_suspend_start);
2061 
2062 void __suspend_report_result(const char *function, void *fn, int ret)
2063 {
2064         if (ret)
2065                 pr_err("%s(): %pS returns %d\n", function, fn, ret);
2066 }
2067 EXPORT_SYMBOL_GPL(__suspend_report_result);
2068 
2069 /**
2070  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
2071  * @subordinate: Device that needs to wait for @dev.
2072  * @dev: Device to wait for.
2073  */
2074 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
2075 {
2076         dpm_wait(dev, subordinate->power.async_suspend);
2077         return async_error;
2078 }
2079 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
2080 
2081 /**
2082  * dpm_for_each_dev - device iterator.
2083  * @data: data for the callback.
2084  * @fn: function to be called for each device.
2085  *
2086  * Iterate over devices in dpm_list, and call @fn for each device,
2087  * passing it @data.
2088  */
2089 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
2090 {
2091         struct device *dev;
2092 
2093         if (!fn)
2094                 return;
2095 
2096         device_pm_lock();
2097         list_for_each_entry(dev, &dpm_list, power.entry)
2098                 fn(dev, data);
2099         device_pm_unlock();
2100 }
2101 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2102 
2103 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2104 {
2105         if (!ops)
2106                 return true;
2107 
2108         return !ops->prepare &&
2109                !ops->suspend &&
2110                !ops->suspend_late &&
2111                !ops->suspend_noirq &&
2112                !ops->resume_noirq &&
2113                !ops->resume_early &&
2114                !ops->resume &&
2115                !ops->complete;
2116 }
2117 
2118 void device_pm_check_callbacks(struct device *dev)
2119 {
2120         spin_lock_irq(&dev->power.lock);
2121         dev->power.no_pm_callbacks =
2122                 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2123                  !dev->bus->suspend && !dev->bus->resume)) &&
2124                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2125                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2126                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2127                 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2128                  !dev->driver->suspend && !dev->driver->resume));
2129         spin_unlock_irq(&dev->power.lock);
2130 }
2131 
2132 bool dev_pm_smart_suspend_and_suspended(struct device *dev)
2133 {
2134         return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2135                 pm_runtime_status_suspended(dev);
2136 }
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root/drivers/base/power/main.c

DEFINITIONS
