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runtime.c
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linux-6.19.14/drivers/base/power/runtime.c
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * drivers/base/power/runtime.c - Helper functions for device runtime PM 4 * 5 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 6 * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu> 7 */ 8#include <linux/sched/mm.h> 9#include <linux/ktime.h> 10#include <linux/hrtimer.h> 11#include <linux/export.h> 12#include <linux/pm_runtime.h> 13#include <linux/pm_wakeirq.h> 14#include <linux/rculist.h> 15#include <trace/events/rpm.h> 16 17#include "../base.h" 18#include "power.h" 19 20typedef int (*pm_callback_t)(struct device *); 21 22static inline pm_callback_t get_callback_ptr(const void *start, size_t offset) 23{ 24 return *(pm_callback_t *)(start + offset); 25} 26 27static pm_callback_t __rpm_get_driver_callback(struct device *dev, 28 size_t cb_offset) 29{ 30 if (dev->driver && dev->driver->pm) 31 return get_callback_ptr(dev->driver->pm, cb_offset); 32 33 return NULL; 34} 35 36static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset) 37{ 38 const struct dev_pm_ops *ops; 39 pm_callback_t cb = NULL; 40 41 if (dev->pm_domain) 42 ops = &dev->pm_domain->ops; 43 else if (dev->type && dev->type->pm) 44 ops = dev->type->pm; 45 else if (dev->class && dev->class->pm) 46 ops = dev->class->pm; 47 else if (dev->bus && dev->bus->pm) 48 ops = dev->bus->pm; 49 else 50 ops = NULL; 51 52 if (ops) 53 cb = get_callback_ptr(ops, cb_offset); 54 55 if (!cb) 56 cb = __rpm_get_driver_callback(dev, cb_offset); 57 58 return cb; 59} 60 61#define RPM_GET_CALLBACK(dev, callback) \ 62 __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback)) 63 64static int rpm_resume(struct device *dev, int rpmflags); 65static int rpm_suspend(struct device *dev, int rpmflags); 66 67/** 68 * update_pm_runtime_accounting - Update the time accounting of power states 69 * @dev: Device to update the accounting for 70 * 71 * In order to be able to have time accounting of the various power states 72 * (as used by programs such as PowerTOP to show the effectiveness of runtime 73 * PM), we need to track the time spent in each state. 74 * update_pm_runtime_accounting must be called each time before the 75 * runtime_status field is updated, to account the time in the old state 76 * correctly. 77 */ 78static void update_pm_runtime_accounting(struct device *dev) 79{ 80 u64 now, last, delta; 81 82 if (dev->power.disable_depth > 0) 83 return; 84 85 last = dev->power.accounting_timestamp; 86 87 now = ktime_get_mono_fast_ns(); 88 dev->power.accounting_timestamp = now; 89 90 /* 91 * Because ktime_get_mono_fast_ns() is not monotonic during 92 * timekeeping updates, ensure that 'now' is after the last saved 93 * timestamp. 94 */ 95 if (now < last) 96 return; 97 98 delta = now - last; 99 100 if (dev->power.runtime_status == RPM_SUSPENDED) 101 dev->power.suspended_time += delta; 102 else 103 dev->power.active_time += delta; 104} 105 106static void __update_runtime_status(struct device *dev, enum rpm_status status) 107{ 108 update_pm_runtime_accounting(dev); 109 trace_rpm_status(dev, status); 110 dev->power.runtime_status = status; 111} 112 113static u64 rpm_get_accounted_time(struct device *dev, bool suspended) 114{ 115 u64 time; 116 unsigned long flags; 117 118 spin_lock_irqsave(&dev->power.lock, flags); 119 120 update_pm_runtime_accounting(dev); 121 time = suspended ? dev->power.suspended_time : dev->power.active_time; 122 123 spin_unlock_irqrestore(&dev->power.lock, flags); 124 125 return time; 126} 127 128u64 pm_runtime_active_time(struct device *dev) 129{ 130 return rpm_get_accounted_time(dev, false); 131} 132 133u64 pm_runtime_suspended_time(struct device *dev) 134{ 135 return rpm_get_accounted_time(dev, true); 136} 137EXPORT_SYMBOL_GPL(pm_runtime_suspended_time); 138 139/** 140 * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. 141 * @dev: Device to handle. 142 */ 143static void pm_runtime_deactivate_timer(struct device *dev) 144{ 145 if (dev->power.timer_expires > 0) { 146 hrtimer_try_to_cancel(&dev->power.suspend_timer); 147 dev->power.timer_expires = 0; 148 } 149} 150 151/** 152 * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests. 153 * @dev: Device to handle. 154 */ 155static void pm_runtime_cancel_pending(struct device *dev) 156{ 157 pm_runtime_deactivate_timer(dev); 158 /* 159 * In case there's a request pending, make sure its work function will 160 * return without doing anything. 161 */ 162 dev->power.request = RPM_REQ_NONE; 163} 164 165/* 166 * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time. 167 * @dev: Device to handle. 168 * 169 * Compute the autosuspend-delay expiration time based on the device's 170 * power.last_busy time. If the delay has already expired or is disabled 171 * (negative) or the power.use_autosuspend flag isn't set, return 0. 172 * Otherwise return the expiration time in nanoseconds (adjusted to be nonzero). 173 * 174 * This function may be called either with or without dev->power.lock held. 175 * Either way it can be racy, since power.last_busy may be updated at any time. 176 */ 177u64 pm_runtime_autosuspend_expiration(struct device *dev) 178{ 179 int autosuspend_delay; 180 u64 expires; 181 182 if (!dev->power.use_autosuspend) 183 return 0; 184 185 autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); 186 if (autosuspend_delay < 0) 187 return 0; 188 189 expires = READ_ONCE(dev->power.last_busy); 190 expires += (u64)autosuspend_delay * NSEC_PER_MSEC; 191 if (expires > ktime_get_mono_fast_ns()) 192 return expires; /* Expires in the future */ 193 194 return 0; 195} 196EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration); 197 198static int dev_memalloc_noio(struct device *dev, void *data) 199{ 200 return dev->power.memalloc_noio; 201} 202 203/* 204 * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag. 205 * @dev: Device to handle. 206 * @enable: True for setting the flag and False for clearing the flag. 207 * 208 * Set the flag for all devices in the path from the device to the 209 * root device in the device tree if @enable is true, otherwise clear 210 * the flag for devices in the path whose siblings don't set the flag. 211 * 212 * The function should only be called by block device, or network 213 * device driver for solving the deadlock problem during runtime 214 * resume/suspend: 215 * 216 * If memory allocation with GFP_KERNEL is called inside runtime 217 * resume/suspend callback of any one of its ancestors(or the 218 * block device itself), the deadlock may be triggered inside the 219 * memory allocation since it might not complete until the block 220 * device becomes active and the involved page I/O finishes. The 221 * situation is pointed out first by Alan Stern. Network device 222 * are involved in iSCSI kind of situation. 223 * 224 * The lock of dev_hotplug_mutex is held in the function for handling 225 * hotplug race because pm_runtime_set_memalloc_noio() may be called 226 * in async probe(). 227 * 228 * The function should be called between device_add() and device_del() 229 * on the affected device(block/network device). 230 */ 231void pm_runtime_set_memalloc_noio(struct device *dev, bool enable) 232{ 233 static DEFINE_MUTEX(dev_hotplug_mutex); 234 235 mutex_lock(&dev_hotplug_mutex); 236 for (;;) { 237 bool enabled; 238 239 /* hold power lock since bitfield is not SMP-safe. */ 240 spin_lock_irq(&dev->power.lock); 241 enabled = dev->power.memalloc_noio; 242 dev->power.memalloc_noio = enable; 243 spin_unlock_irq(&dev->power.lock); 244 245 /* 246 * not need to enable ancestors any more if the device 247 * has been enabled. 248 */ 249 if (enabled && enable) 250 break; 251 252 dev = dev->parent; 253 254 /* 255 * clear flag of the parent device only if all the 256 * children don't set the flag because ancestor's 257 * flag was set by any one of the descendants. 258 */ 259 if (!dev || (!enable && 260 device_for_each_child(dev, NULL, dev_memalloc_noio))) 261 break; 262 } 263 mutex_unlock(&dev_hotplug_mutex); 264} 265EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio); 266 267/** 268 * rpm_check_suspend_allowed - Test whether a device may be suspended. 269 * @dev: Device to test. 270 */ 271static int rpm_check_suspend_allowed(struct device *dev) 272{ 273 int retval = 0; 274 275 if (dev->power.runtime_error) 276 retval = -EINVAL; 277 else if (dev->power.disable_depth > 0) 278 retval = -EACCES; 279 else if (atomic_read(&dev->power.usage_count)) 280 retval = -EAGAIN; 281 else if (!dev->power.ignore_children && atomic_read(&dev->power.child_count)) 282 retval = -EBUSY; 283 284 /* Pending resume requests take precedence over suspends. */ 285 else if ((dev->power.deferred_resume && 286 dev->power.runtime_status == RPM_SUSPENDING) || 287 (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME)) 288 retval = -EAGAIN; 289 else if (__dev_pm_qos_resume_latency(dev) == 0) 290 retval = -EPERM; 291 else if (dev->power.runtime_status == RPM_SUSPENDED) 292 retval = 1; 293 294 return retval; 295} 296 297static int rpm_get_suppliers(struct device *dev) 298{ 299 struct device_link *link; 300 301 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, 302 device_links_read_lock_held()) { 303 int retval; 304 305 if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) 306 continue; 307 308 retval = pm_runtime_get_sync(link->supplier); 309 /* Ignore suppliers with disabled runtime PM. */ 310 if (retval < 0 && retval != -EACCES) { 311 pm_runtime_put_noidle(link->supplier); 312 return retval; 313 } 314 refcount_inc(&link->rpm_active); 315 } 316 return 0; 317} 318 319/** 320 * pm_runtime_release_supplier - Drop references to device link's supplier. 321 * @link: Target device link. 322 * 323 * Drop all runtime PM references associated with @link to its supplier device. 324 */ 325void pm_runtime_release_supplier(struct device_link *link) 326{ 327 struct device *supplier = link->supplier; 328 329 /* 330 * The additional power.usage_count check is a safety net in case 331 * the rpm_active refcount becomes saturated, in which case 332 * refcount_dec_not_one() would return true forever, but it is not 333 * strictly necessary. 334 */ 335 while (refcount_dec_not_one(&link->rpm_active) && 336 atomic_read(&supplier->power.usage_count) > 0) 337 pm_runtime_put_noidle(supplier); 338} 339 340static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) 341{ 342 struct device_link *link; 343 344 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, 345 device_links_read_lock_held()) { 346 pm_runtime_release_supplier(link); 347 if (try_to_suspend) 348 pm_request_idle(link->supplier); 349 } 350} 351 352static void rpm_put_suppliers(struct device *dev) 353{ 354 __rpm_put_suppliers(dev, true); 355} 356 357static void rpm_suspend_suppliers(struct device *dev) 358{ 359 struct device_link *link; 360 int idx = device_links_read_lock(); 361 362 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, 363 device_links_read_lock_held()) 364 pm_request_idle(link->supplier); 365 366 device_links_read_unlock(idx); 367} 368 369/** 370 * __rpm_callback - Run a given runtime PM callback for a given device. 371 * @cb: Runtime PM callback to run. 372 * @dev: Device to run the callback for. 373 */ 374static int __rpm_callback(int (*cb)(struct device *), struct device *dev) 375 __releases(&dev->power.lock) __acquires(&dev->power.lock) 376{ 377 int retval = 0, idx; 378 bool use_links = dev->power.links_count > 0; 379 380 if (dev->power.irq_safe) { 381 spin_unlock(&dev->power.lock); 382 } else { 383 spin_unlock_irq(&dev->power.lock); 384 385 /* 386 * Resume suppliers if necessary. 387 * 388 * The device's runtime PM status cannot change until this 389 * routine returns, so it is safe to read the status outside of 390 * the lock. 391 */ 392 if (use_links && dev->power.runtime_status == RPM_RESUMING) { 393 idx = device_links_read_lock(); 394 395 retval = rpm_get_suppliers(dev); 396 if (retval) { 397 rpm_put_suppliers(dev); 398 goto fail; 399 } 400 401 device_links_read_unlock(idx); 402 } 403 } 404 405 if (cb) 406 retval = cb(dev); 407 408 if (dev->power.irq_safe) { 409 spin_lock(&dev->power.lock); 410 } else { 411 /* 412 * If the device is suspending and the callback has returned 413 * success, drop the usage counters of the suppliers that have 414 * been reference counted on its resume. 415 * 416 * Do that if resume fails too. 417 */ 418 if (use_links && 419 ((dev->power.runtime_status == RPM_SUSPENDING && !retval) || 420 (dev->power.runtime_status == RPM_RESUMING && retval))) { 421 idx = device_links_read_lock(); 422 423 __rpm_put_suppliers(dev, false); 424 425fail: 426 device_links_read_unlock(idx); 427 } 428 429 spin_lock_irq(&dev->power.lock); 430 } 431 432 return retval; 433} 434 435/** 436 * rpm_callback - Run a given runtime PM callback for a given device. 437 * @cb: Runtime PM callback to run. 438 * @dev: Device to run the callback for. 439 */ 440static int rpm_callback(int (*cb)(struct device *), struct device *dev) 441{ 442 int retval; 443 444 if (dev->power.memalloc_noio) { 445 unsigned int noio_flag; 446 447 /* 448 * Deadlock might be caused if memory allocation with 449 * GFP_KERNEL happens inside runtime_suspend and 450 * runtime_resume callbacks of one block device's 451 * ancestor or the block device itself. Network 452 * device might be thought as part of iSCSI block 453 * device, so network device and its ancestor should 454 * be marked as memalloc_noio too. 455 */ 456 noio_flag = memalloc_noio_save(); 457 retval = __rpm_callback(cb, dev); 458 memalloc_noio_restore(noio_flag); 459 } else { 460 retval = __rpm_callback(cb, dev); 461 } 462 463 /* 464 * Since -EACCES means that runtime PM is disabled for the given device, 465 * it should not be returned by runtime PM callbacks. If it is returned 466 * nevertheless, assume it to be a transient error and convert it to 467 * -EAGAIN. 468 */ 469 if (retval == -EACCES) 470 retval = -EAGAIN; 471 472 if (retval != -EAGAIN && retval != -EBUSY) 473 dev->power.runtime_error = retval; 474 475 return retval; 476} 477 478/** 479 * rpm_idle - Notify device bus type if the device can be suspended. 480 * @dev: Device to notify the bus type about. 481 * @rpmflags: Flag bits. 482 * 483 * Check if the device's runtime PM status allows it to be suspended. If 484 * another idle notification has been started earlier, return immediately. If 485 * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise 486 * run the ->runtime_idle() callback directly. If the ->runtime_idle callback 487 * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag. 488 * 489 * This function must be called under dev->power.lock with interrupts disabled. 490 */ 491static int rpm_idle(struct device *dev, int rpmflags) 492{ 493 int (*callback)(struct device *); 494 int retval; 495 496 trace_rpm_idle(dev, rpmflags); 497 retval = rpm_check_suspend_allowed(dev); 498 if (retval < 0) 499 ; /* Conditions are wrong. */ 500 501 else if ((rpmflags & RPM_GET_PUT) && retval == 1) 502 ; /* put() is allowed in RPM_SUSPENDED */ 503 504 /* Idle notifications are allowed only in the RPM_ACTIVE state. */ 505 else if (dev->power.runtime_status != RPM_ACTIVE) 506 retval = -EAGAIN; 507 508 /* 509 * Any pending request other than an idle notification takes 510 * precedence over us, except that the timer may be running. 511 */ 512 else if (dev->power.request_pending && 513 dev->power.request > RPM_REQ_IDLE) 514 retval = -EAGAIN; 515 516 /* Act as though RPM_NOWAIT is always set. */ 517 else if (dev->power.idle_notification) 518 retval = -EINPROGRESS; 519 520 if (retval) 521 goto out; 522 523 /* Pending requests need to be canceled. */ 524 dev->power.request = RPM_REQ_NONE; 525 526 callback = RPM_GET_CALLBACK(dev, runtime_idle); 527 528 /* If no callback assume success. */ 529 if (!callback || dev->power.no_callbacks) 530 goto out; 531 532 /* Carry out an asynchronous or a synchronous idle notification. */ 533 if (rpmflags & RPM_ASYNC) { 534 dev->power.request = RPM_REQ_IDLE; 535 if (!dev->power.request_pending) { 536 dev->power.request_pending = true; 537 queue_work(pm_wq, &dev->power.work); 538 } 539 trace_rpm_return_int(dev, _THIS_IP_, 0); 540 return 0; 541 } 542 543 dev->power.idle_notification = true; 544 545 if (dev->power.irq_safe) 546 spin_unlock(&dev->power.lock); 547 else 548 spin_unlock_irq(&dev->power.lock); 549 550 retval = callback(dev); 551 552 if (dev->power.irq_safe) 553 spin_lock(&dev->power.lock); 554 else 555 spin_lock_irq(&dev->power.lock); 556 557 dev->power.idle_notification = false; 558 wake_up_all(&dev->power.wait_queue); 559 560 out: 561 trace_rpm_return_int(dev, _THIS_IP_, retval); 562 return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO); 563} 564 565/** 566 * rpm_suspend - Carry out runtime suspend of given device. 567 * @dev: Device to suspend. 568 * @rpmflags: Flag bits. 569 * 570 * Check if the device's runtime PM status allows it to be suspended. 571 * Cancel a pending idle notification, autosuspend or suspend. If 572 * another suspend has been started earlier, either return immediately 573 * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC 574 * flags. If the RPM_ASYNC flag is set then queue a suspend request; 575 * otherwise run the ->runtime_suspend() callback directly. When 576 * ->runtime_suspend succeeded, if a deferred resume was requested while 577 * the callback was running then carry it out, otherwise send an idle 578 * notification for its parent (if the suspend succeeded and both 579 * ignore_children of parent->power and irq_safe of dev->power are not set). 580 * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO 581 * flag is set and the next autosuspend-delay expiration time is in the 582 * future, schedule another autosuspend attempt. 583 * 584 * This function must be called under dev->power.lock with interrupts disabled. 585 */ 586static int rpm_suspend(struct device *dev, int rpmflags) 587 __releases(&dev->power.lock) __acquires(&dev->power.lock) 588{ 589 int (*callback)(struct device *); 590 struct device *parent = NULL; 591 int retval; 592 593 trace_rpm_suspend(dev, rpmflags); 594 595 repeat: 596 retval = rpm_check_suspend_allowed(dev); 597 if (retval < 0) 598 goto out; /* Conditions are wrong. */ 599 600 /* Synchronous suspends are not allowed in the RPM_RESUMING state. */ 601 if (dev->power.runtime_status == RPM_RESUMING && !(rpmflags & RPM_ASYNC)) 602 retval = -EAGAIN; 603 604 if (retval) 605 goto out; 606 607 /* If the autosuspend_delay time hasn't expired yet, reschedule. */ 608 if ((rpmflags & RPM_AUTO) && dev->power.runtime_status != RPM_SUSPENDING) { 609 u64 expires = pm_runtime_autosuspend_expiration(dev); 610 611 if (expires != 0) { 612 /* Pending requests need to be canceled. */ 613 dev->power.request = RPM_REQ_NONE; 614 615 /* 616 * Optimization: If the timer is already running and is 617 * set to expire at or before the autosuspend delay, 618 * avoid the overhead of resetting it. Just let it 619 * expire; pm_suspend_timer_fn() will take care of the 620 * rest. 621 */ 622 if (!(dev->power.timer_expires && 623 dev->power.timer_expires <= expires)) { 624 /* 625 * We add a slack of 25% to gather wakeups 626 * without sacrificing the granularity. 627 */ 628 u64 slack = (u64)READ_ONCE(dev->power.autosuspend_delay) * 629 (NSEC_PER_MSEC >> 2); 630 631 dev->power.timer_expires = expires; 632 hrtimer_start_range_ns(&dev->power.suspend_timer, 633 ns_to_ktime(expires), 634 slack, 635 HRTIMER_MODE_ABS); 636 } 637 dev->power.timer_autosuspends = 1; 638 goto out; 639 } 640 } 641 642 /* Other scheduled or pending requests need to be canceled. */ 643 pm_runtime_cancel_pending(dev); 644 645 if (dev->power.runtime_status == RPM_SUSPENDING) { 646 DEFINE_WAIT(wait); 647 648 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { 649 retval = -EINPROGRESS; 650 goto out; 651 } 652 653 if (dev->power.irq_safe) { 654 spin_unlock(&dev->power.lock); 655 656 cpu_relax(); 657 658 spin_lock(&dev->power.lock); 659 goto repeat; 660 } 661 662 /* Wait for the other suspend running in parallel with us. */ 663 for (;;) { 664 prepare_to_wait(&dev->power.wait_queue, &wait, 665 TASK_UNINTERRUPTIBLE); 666 if (dev->power.runtime_status != RPM_SUSPENDING) 667 break; 668 669 spin_unlock_irq(&dev->power.lock); 670 671 schedule(); 672 673 spin_lock_irq(&dev->power.lock); 674 } 675 finish_wait(&dev->power.wait_queue, &wait); 676 goto repeat; 677 } 678 679 if (dev->power.no_callbacks) 680 goto no_callback; /* Assume success. */ 681 682 /* Carry out an asynchronous or a synchronous suspend. */ 683 if (rpmflags & RPM_ASYNC) { 684 dev->power.request = (rpmflags & RPM_AUTO) ? 685 RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND; 686 if (!dev->power.request_pending) { 687 dev->power.request_pending = true; 688 queue_work(pm_wq, &dev->power.work); 689 } 690 goto out; 691 } 692 693 __update_runtime_status(dev, RPM_SUSPENDING); 694 695 callback = RPM_GET_CALLBACK(dev, runtime_suspend); 696 697 dev_pm_enable_wake_irq_check(dev, true); 698 retval = rpm_callback(callback, dev); 699 if (retval) 700 goto fail; 701 702 dev_pm_enable_wake_irq_complete(dev); 703 704 no_callback: 705 __update_runtime_status(dev, RPM_SUSPENDED); 706 pm_runtime_deactivate_timer(dev); 707 708 if (dev->parent) { 709 parent = dev->parent; 710 atomic_add_unless(&parent->power.child_count, -1, 0); 711 } 712 wake_up_all(&dev->power.wait_queue); 713 714 if (dev->power.deferred_resume) { 715 dev->power.deferred_resume = false; 716 rpm_resume(dev, 0); 717 retval = -EAGAIN; 718 goto out; 719 } 720 721 if (dev->power.irq_safe) 722 goto out; 723 724 /* Maybe the parent is now able to suspend. */ 725 if (parent && !parent->power.ignore_children) { 726 spin_unlock(&dev->power.lock); 727 728 spin_lock(&parent->power.lock); 729 rpm_idle(parent, RPM_ASYNC); 730 spin_unlock(&parent->power.lock); 731 732 spin_lock(&dev->power.lock); 733 } 734 /* Maybe the suppliers are now able to suspend. */ 735 if (dev->power.links_count > 0) { 736 spin_unlock_irq(&dev->power.lock); 737 738 rpm_suspend_suppliers(dev); 739 740 spin_lock_irq(&dev->power.lock); 741 } 742 743 out: 744 trace_rpm_return_int(dev, _THIS_IP_, retval); 745 746 return retval; 747 748 fail: 749 dev_pm_disable_wake_irq_check(dev, true); 750 __update_runtime_status(dev, RPM_ACTIVE); 751 dev->power.deferred_resume = false; 752 wake_up_all(&dev->power.wait_queue); 753 754 /* 755 * On transient errors, if the callback routine failed an autosuspend, 756 * and if the last_busy time has been updated so that there is a new 757 * autosuspend expiration time, automatically reschedule another 758 * autosuspend. 759 */ 760 if (!dev->power.runtime_error && (rpmflags & RPM_AUTO) && 761 pm_runtime_autosuspend_expiration(dev) != 0) 762 goto repeat; 763 764 pm_runtime_cancel_pending(dev); 765 766 goto out; 767} 768 769/** 770 * rpm_resume - Carry out runtime resume of given device. 771 * @dev: Device to resume. 772 * @rpmflags: Flag bits. 773 * 774 * Check if the device's runtime PM status allows it to be resumed. Cancel 775 * any scheduled or pending requests. If another resume has been started 776 * earlier, either return immediately or wait for it to finish, depending on the 777 * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in 778 * parallel with this function, either tell the other process to resume after 779 * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC 780 * flag is set then queue a resume request; otherwise run the 781 * ->runtime_resume() callback directly. Queue an idle notification for the 782 * device if the resume succeeded. 783 * 784 * This function must be called under dev->power.lock with interrupts disabled. 785 */ 786static int rpm_resume(struct device *dev, int rpmflags) 787 __releases(&dev->power.lock) __acquires(&dev->power.lock) 788{ 789 int (*callback)(struct device *); 790 struct device *parent = NULL; 791 int retval = 0; 792 793 trace_rpm_resume(dev, rpmflags); 794 795 repeat: 796 if (dev->power.runtime_error) { 797 retval = -EINVAL; 798 } else if (dev->power.disable_depth > 0) { 799 if (dev->power.runtime_status == RPM_ACTIVE && 800 dev->power.last_status == RPM_ACTIVE) 801 retval = 1; 802 else if (rpmflags & RPM_TRANSPARENT) 803 goto out; 804 else 805 retval = -EACCES; 806 } 807 if (retval) 808 goto out; 809 810 /* 811 * Other scheduled or pending requests need to be canceled. Small 812 * optimization: If an autosuspend timer is running, leave it running 813 * rather than cancelling it now only to restart it again in the near 814 * future. 815 */ 816 dev->power.request = RPM_REQ_NONE; 817 if (!dev->power.timer_autosuspends) 818 pm_runtime_deactivate_timer(dev); 819 820 if (dev->power.runtime_status == RPM_ACTIVE) { 821 retval = 1; 822 goto out; 823 } 824 825 if (dev->power.runtime_status == RPM_RESUMING || 826 dev->power.runtime_status == RPM_SUSPENDING) { 827 DEFINE_WAIT(wait); 828 829 if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { 830 if (dev->power.runtime_status == RPM_SUSPENDING) { 831 dev->power.deferred_resume = true; 832 if (rpmflags & RPM_NOWAIT) 833 retval = -EINPROGRESS; 834 } else { 835 retval = -EINPROGRESS; 836 } 837 goto out; 838 } 839 840 if (dev->power.irq_safe) { 841 spin_unlock(&dev->power.lock); 842 843 cpu_relax(); 844 845 spin_lock(&dev->power.lock); 846 goto repeat; 847 } 848 849 /* Wait for the operation carried out in parallel with us. */ 850 for (;;) { 851 prepare_to_wait(&dev->power.wait_queue, &wait, 852 TASK_UNINTERRUPTIBLE); 853 if (dev->power.runtime_status != RPM_RESUMING && 854 dev->power.runtime_status != RPM_SUSPENDING) 855 break; 856 857 spin_unlock_irq(&dev->power.lock); 858 859 schedule(); 860 861 spin_lock_irq(&dev->power.lock); 862 } 863 finish_wait(&dev->power.wait_queue, &wait); 864 goto repeat; 865 } 866 867 /* 868 * See if we can skip waking up the parent. This is safe only if 869 * power.no_callbacks is set, because otherwise we don't know whether 870 * the resume will actually succeed. 871 */ 872 if (dev->power.no_callbacks && !parent && dev->parent) { 873 spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING); 874 if (dev->parent->power.disable_depth > 0 || 875 dev->parent->power.ignore_children || 876 dev->parent->power.runtime_status == RPM_ACTIVE) { 877 atomic_inc(&dev->parent->power.child_count); 878 spin_unlock(&dev->parent->power.lock); 879 retval = 1; 880 goto no_callback; /* Assume success. */ 881 } 882 spin_unlock(&dev->parent->power.lock); 883 } 884 885 /* Carry out an asynchronous or a synchronous resume. */ 886 if (rpmflags & RPM_ASYNC) { 887 dev->power.request = RPM_REQ_RESUME; 888 if (!dev->power.request_pending) { 889 dev->power.request_pending = true; 890 queue_work(pm_wq, &dev->power.work); 891 } 892 retval = 0; 893 goto out; 894 } 895 896 if (!parent && dev->parent) { 897 /* 898 * Increment the parent's usage counter and resume it if 899 * necessary. Not needed if dev is irq-safe; then the 900 * parent is permanently resumed. 901 */ 902 parent = dev->parent; 903 if (dev->power.irq_safe) 904 goto skip_parent; 905 906 spin_unlock(&dev->power.lock); 907 908 pm_runtime_get_noresume(parent); 909 910 spin_lock(&parent->power.lock); 911 /* 912 * Resume the parent if it has runtime PM enabled and not been 913 * set to ignore its children. 914 */ 915 if (!parent->power.disable_depth && 916 !parent->power.ignore_children) { 917 rpm_resume(parent, 0); 918 if (parent->power.runtime_status != RPM_ACTIVE) 919 retval = -EBUSY; 920 } 921 spin_unlock(&parent->power.lock); 922 923 spin_lock(&dev->power.lock); 924 if (retval) 925 goto out; 926 927 goto repeat; 928 } 929 skip_parent: 930 931 if (dev->power.no_callbacks) 932 goto no_callback; /* Assume success. */ 933 934 __update_runtime_status(dev, RPM_RESUMING); 935 936 callback = RPM_GET_CALLBACK(dev, runtime_resume); 937 938 dev_pm_disable_wake_irq_check(dev, false); 939 retval = rpm_callback(callback, dev); 940 if (retval) { 941 __update_runtime_status(dev, RPM_SUSPENDED); 942 pm_runtime_cancel_pending(dev); 943 dev_pm_enable_wake_irq_check(dev, false); 944 } else { 945 no_callback: 946 __update_runtime_status(dev, RPM_ACTIVE); 947 pm_runtime_mark_last_busy(dev); 948 if (parent) 949 atomic_inc(&parent->power.child_count); 950 } 951 wake_up_all(&dev->power.wait_queue); 952 953 if (retval >= 0) 954 rpm_idle(dev, RPM_ASYNC); 955 956 out: 957 if (parent && !dev->power.irq_safe) { 958 spin_unlock_irq(&dev->power.lock); 959 960 pm_runtime_put(parent); 961 962 spin_lock_irq(&dev->power.lock); 963 } 964 965 trace_rpm_return_int(dev, _THIS_IP_, retval); 966 967 return retval; 968} 969 970/** 971 * pm_runtime_work - Universal runtime PM work function. 972 * @work: Work structure used for scheduling the execution of this function. 973 * 974 * Use @work to get the device object the work is to be done for, determine what 975 * is to be done and execute the appropriate runtime PM function. 976 */ 977static void pm_runtime_work(struct work_struct *work) 978{ 979 struct device *dev = container_of(work, struct device, power.work); 980 enum rpm_request req; 981 982 spin_lock_irq(&dev->power.lock); 983 984 if (!dev->power.request_pending) 985 goto out; 986 987 req = dev->power.request; 988 dev->power.request = RPM_REQ_NONE; 989 dev->power.request_pending = false; 990 991 switch (req) { 992 case RPM_REQ_NONE: 993 break; 994 case RPM_REQ_IDLE: 995 rpm_idle(dev, RPM_NOWAIT); 996 break; 997 case RPM_REQ_SUSPEND: 998 rpm_suspend(dev, RPM_NOWAIT); 999 break; 1000 case RPM_REQ_AUTOSUSPEND: 1001 rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); 1002 break; 1003 case RPM_REQ_RESUME: 1004 rpm_resume(dev, RPM_NOWAIT); 1005 break; 1006 } 1007 1008 out: 1009 spin_unlock_irq(&dev->power.lock); 1010} 1011 1012/** 1013 * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). 1014 * @timer: hrtimer used by pm_schedule_suspend(). 1015 * 1016 * Check if the time is right and queue a suspend request. 1017 */ 1018static enum hrtimer_restart pm_suspend_timer_fn(struct hrtimer *timer) 1019{ 1020 struct device *dev = container_of(timer, struct device, power.suspend_timer); 1021 unsigned long flags; 1022 u64 expires; 1023 1024 spin_lock_irqsave(&dev->power.lock, flags); 1025 1026 expires = dev->power.timer_expires; 1027 /* 1028 * If 'expires' is after the current time, we've been called 1029 * too early. 1030 */ 1031 if (expires > 0 && expires <= ktime_get_mono_fast_ns()) { 1032 dev->power.timer_expires = 0; 1033 rpm_suspend(dev, dev->power.timer_autosuspends ? 1034 (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC); 1035 } 1036 1037 spin_unlock_irqrestore(&dev->power.lock, flags); 1038 1039 return HRTIMER_NORESTART; 1040} 1041 1042/** 1043 * pm_schedule_suspend - Set up a timer to submit a suspend request in future. 1044 * @dev: Device to suspend. 1045 * @delay: Time to wait before submitting a suspend request, in milliseconds. 1046 */ 1047int pm_schedule_suspend(struct device *dev, unsigned int delay) 1048{ 1049 unsigned long flags; 1050 u64 expires; 1051 int retval; 1052 1053 spin_lock_irqsave(&dev->power.lock, flags); 1054 1055 if (!delay) { 1056 retval = rpm_suspend(dev, RPM_ASYNC); 1057 goto out; 1058 } 1059 1060 retval = rpm_check_suspend_allowed(dev); 1061 if (retval) 1062 goto out; 1063 1064 /* Other scheduled or pending requests need to be canceled. */ 1065 pm_runtime_cancel_pending(dev); 1066 1067 expires = ktime_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC; 1068 dev->power.timer_expires = expires; 1069 dev->power.timer_autosuspends = 0; 1070 hrtimer_start(&dev->power.suspend_timer, expires, HRTIMER_MODE_ABS); 1071 1072 out: 1073 spin_unlock_irqrestore(&dev->power.lock, flags); 1074 1075 return retval; 1076} 1077EXPORT_SYMBOL_GPL(pm_schedule_suspend); 1078 1079static int rpm_drop_usage_count(struct device *dev) 1080{ 1081 int ret; 1082 1083 ret = atomic_sub_return(1, &dev->power.usage_count); 1084 if (ret >= 0) 1085 return ret; 1086 1087 /* 1088 * Because rpm_resume() does not check the usage counter, it will resume 1089 * the device even if the usage counter is 0 or negative, so it is 1090 * sufficient to increment the usage counter here to reverse the change 1091 * made above. 1092 */ 1093 atomic_inc(&dev->power.usage_count); 1094 dev_warn(dev, "Runtime PM usage count underflow!\n"); 1095 return -EINVAL; 1096} 1097 1098/** 1099 * __pm_runtime_idle - Entry point for runtime idle operations. 1100 * @dev: Device to send idle notification for. 1101 * @rpmflags: Flag bits. 1102 * 1103 * If the RPM_GET_PUT flag is set, decrement the device's usage count and 1104 * return immediately if it is larger than zero (if it becomes negative, log a 1105 * warning, increment it, and return an error). Then carry out an idle 1106 * notification, either synchronous or asynchronous. 1107 * 1108 * This routine may be called in atomic context if the RPM_ASYNC flag is set, 1109 * or if pm_runtime_irq_safe() has been called. 1110 */ 1111int __pm_runtime_idle(struct device *dev, int rpmflags) 1112{ 1113 unsigned long flags; 1114 int retval; 1115 1116 if (rpmflags & RPM_GET_PUT) { 1117 retval = rpm_drop_usage_count(dev); 1118 if (retval < 0) { 1119 return retval; 1120 } else if (retval > 0) { 1121 trace_rpm_usage(dev, rpmflags); 1122 return 0; 1123 } 1124 } 1125 1126 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); 1127 1128 spin_lock_irqsave(&dev->power.lock, flags); 1129 retval = rpm_idle(dev, rpmflags); 1130 spin_unlock_irqrestore(&dev->power.lock, flags); 1131 1132 return retval; 1133} 1134EXPORT_SYMBOL_GPL(__pm_runtime_idle); 1135 1136/** 1137 * __pm_runtime_suspend - Entry point for runtime put/suspend operations. 1138 * @dev: Device to suspend. 1139 * @rpmflags: Flag bits. 1140 * 1141 * If the RPM_GET_PUT flag is set, decrement the device's usage count and 1142 * return immediately if it is larger than zero (if it becomes negative, log a 1143 * warning, increment it, and return an error). Then carry out a suspend, 1144 * either synchronous or asynchronous. 1145 * 1146 * This routine may be called in atomic context if the RPM_ASYNC flag is set, 1147 * or if pm_runtime_irq_safe() has been called. 1148 */ 1149int __pm_runtime_suspend(struct device *dev, int rpmflags) 1150{ 1151 unsigned long flags; 1152 int retval; 1153 1154 if (rpmflags & RPM_GET_PUT) { 1155 retval = rpm_drop_usage_count(dev); 1156 if (retval < 0) { 1157 return retval; 1158 } else if (retval > 0) { 1159 trace_rpm_usage(dev, rpmflags); 1160 return 0; 1161 } 1162 } 1163 1164 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); 1165 1166 spin_lock_irqsave(&dev->power.lock, flags); 1167 retval = rpm_suspend(dev, rpmflags); 1168 spin_unlock_irqrestore(&dev->power.lock, flags); 1169 1170 return retval; 1171} 1172EXPORT_SYMBOL_GPL(__pm_runtime_suspend); 1173 1174/** 1175 * __pm_runtime_resume - Entry point for runtime resume operations. 1176 * @dev: Device to resume. 1177 * @rpmflags: Flag bits. 1178 * 1179 * If the RPM_GET_PUT flag is set, increment the device's usage count. Then 1180 * carry out a resume, either synchronous or asynchronous. 1181 * 1182 * This routine may be called in atomic context if the RPM_ASYNC flag is set, 1183 * or if pm_runtime_irq_safe() has been called. 1184 */ 1185int __pm_runtime_resume(struct device *dev, int rpmflags) 1186{ 1187 unsigned long flags; 1188 int retval; 1189 1190 might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe && 1191 dev->power.runtime_status != RPM_ACTIVE); 1192 1193 if (rpmflags & RPM_GET_PUT) 1194 atomic_inc(&dev->power.usage_count); 1195 1196 spin_lock_irqsave(&dev->power.lock, flags); 1197 retval = rpm_resume(dev, rpmflags); 1198 spin_unlock_irqrestore(&dev->power.lock, flags); 1199 1200 return retval; 1201} 1202EXPORT_SYMBOL_GPL(__pm_runtime_resume); 1203 1204/** 1205 * pm_runtime_get_conditional - Conditionally bump up device usage counter. 1206 * @dev: Device to handle. 1207 * @ign_usage_count: Whether or not to look at the current usage counter value. 1208 * 1209 * Return -EINVAL if runtime PM is disabled for @dev. 1210 * 1211 * Otherwise, if its runtime PM status is %RPM_ACTIVE and (1) @ign_usage_count 1212 * is set, or (2) @dev is not ignoring children and its active child count is 1213 * nonzero, or (3) the runtime PM usage counter of @dev is not zero, increment 1214 * the usage counter of @dev and return 1. 1215 * 1216 * Otherwise, return 0 without changing the usage counter. 1217 * 1218 * If @ign_usage_count is %true, this function can be used to prevent suspending 1219 * the device when its runtime PM status is %RPM_ACTIVE. 1220 * 1221 * If @ign_usage_count is %false, this function can be used to prevent 1222 * suspending the device when both its runtime PM status is %RPM_ACTIVE and its 1223 * runtime PM usage counter is not zero. 1224 * 1225 * The caller is responsible for decrementing the runtime PM usage counter of 1226 * @dev after this function has returned a positive value for it. 1227 */ 1228static int pm_runtime_get_conditional(struct device *dev, bool ign_usage_count) 1229{ 1230 unsigned long flags; 1231 int retval; 1232 1233 spin_lock_irqsave(&dev->power.lock, flags); 1234 if (dev->power.disable_depth > 0) { 1235 retval = -EINVAL; 1236 } else if (dev->power.runtime_status != RPM_ACTIVE) { 1237 retval = 0; 1238 } else if (ign_usage_count || (!dev->power.ignore_children && 1239 atomic_read(&dev->power.child_count) > 0)) { 1240 retval = 1; 1241 atomic_inc(&dev->power.usage_count); 1242 } else { 1243 retval = atomic_inc_not_zero(&dev->power.usage_count); 1244 } 1245 trace_rpm_usage(dev, 0); 1246 spin_unlock_irqrestore(&dev->power.lock, flags); 1247 1248 return retval; 1249} 1250 1251/** 1252 * pm_runtime_get_if_active - Bump up runtime PM usage counter if the device is 1253 * in active state 1254 * @dev: Target device. 1255 * 1256 * Increment the runtime PM usage counter of @dev if its runtime PM status is 1257 * %RPM_ACTIVE, in which case it returns 1. If the device is in a different 1258 * state, 0 is returned. -EINVAL is returned if runtime PM is disabled for the 1259 * device, in which case also the usage_count will remain unmodified. 1260 */ 1261int pm_runtime_get_if_active(struct device *dev) 1262{ 1263 return pm_runtime_get_conditional(dev, true); 1264} 1265EXPORT_SYMBOL_GPL(pm_runtime_get_if_active); 1266 1267/** 1268 * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. 1269 * @dev: Target device. 1270 * 1271 * Increment the runtime PM usage counter of @dev if its runtime PM status is 1272 * %RPM_ACTIVE and its runtime PM usage counter is greater than 0 or it is not 1273 * ignoring children and its active child count is nonzero. 1 is returned in 1274 * this case. 1275 * 1276 * If @dev is in a different state or it is not in use (that is, its usage 1277 * counter is 0, or it is ignoring children, or its active child count is 0), 1278 * 0 is returned. 1279 * 1280 * -EINVAL is returned if runtime PM is disabled for the device, in which case 1281 * also the usage counter of @dev is not updated. 1282 */ 1283int pm_runtime_get_if_in_use(struct device *dev) 1284{ 1285 return pm_runtime_get_conditional(dev, false); 1286} 1287EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); 1288 1289/** 1290 * __pm_runtime_set_status - Set runtime PM status of a device. 1291 * @dev: Device to handle. 1292 * @status: New runtime PM status of the device. 1293 * 1294 * If runtime PM of the device is disabled or its power.runtime_error field is 1295 * different from zero, the status may be changed either to RPM_ACTIVE, or to 1296 * RPM_SUSPENDED, as long as that reflects the actual state of the device. 1297 * However, if the device has a parent and the parent is not active, and the 1298 * parent's power.ignore_children flag is unset, the device's status cannot be 1299 * set to RPM_ACTIVE, so -EBUSY is returned in that case. 1300 * 1301 * If successful, __pm_runtime_set_status() clears the power.runtime_error field 1302 * and the device parent's counter of unsuspended children is modified to 1303 * reflect the new status. If the new status is RPM_SUSPENDED, an idle 1304 * notification request for the parent is submitted. 1305 * 1306 * If @dev has any suppliers (as reflected by device links to them), and @status 1307 * is RPM_ACTIVE, they will be activated upfront and if the activation of one 1308 * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead 1309 * of the @status value) and the suppliers will be deacticated on exit. The 1310 * error returned by the failing supplier activation will be returned in that 1311 * case. 1312 */ 1313int __pm_runtime_set_status(struct device *dev, unsigned int status) 1314{ 1315 struct device *parent = dev->parent; 1316 bool notify_parent = false; 1317 unsigned long flags; 1318 int error = 0; 1319 1320 if (status != RPM_ACTIVE && status != RPM_SUSPENDED) 1321 return -EINVAL; 1322 1323 spin_lock_irqsave(&dev->power.lock, flags); 1324 1325 /* 1326 * Prevent PM-runtime from being enabled for the device or return an 1327 * error if it is enabled already and working. 1328 */ 1329 if (dev->power.runtime_error || dev->power.disable_depth) 1330 dev->power.disable_depth++; 1331 else 1332 error = -EAGAIN; 1333 1334 spin_unlock_irqrestore(&dev->power.lock, flags); 1335 1336 if (error) 1337 return error; 1338 1339 /* 1340 * If the new status is RPM_ACTIVE, the suppliers can be activated 1341 * upfront regardless of the current status, because next time 1342 * rpm_put_suppliers() runs, the rpm_active refcounts of the links 1343 * involved will be dropped down to one anyway. 1344 */ 1345 if (status == RPM_ACTIVE) { 1346 int idx = device_links_read_lock(); 1347 1348 error = rpm_get_suppliers(dev); 1349 if (error) 1350 status = RPM_SUSPENDED; 1351 1352 device_links_read_unlock(idx); 1353 } 1354 1355 spin_lock_irqsave(&dev->power.lock, flags); 1356 1357 if (dev->power.runtime_status == status || !parent) 1358 goto out_set; 1359 1360 if (status == RPM_SUSPENDED) { 1361 atomic_add_unless(&parent->power.child_count, -1, 0); 1362 notify_parent = !parent->power.ignore_children; 1363 } else { 1364 spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING); 1365 1366 /* 1367 * It is invalid to put an active child under a parent that is 1368 * not active, has runtime PM enabled and the 1369 * 'power.ignore_children' flag unset. 1370 */ 1371 if (!parent->power.disable_depth && 1372 !parent->power.ignore_children && 1373 parent->power.runtime_status != RPM_ACTIVE) { 1374 dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n", 1375 dev_name(dev), 1376 dev_name(parent)); 1377 error = -EBUSY; 1378 } else if (dev->power.runtime_status == RPM_SUSPENDED) { 1379 atomic_inc(&parent->power.child_count); 1380 } 1381 1382 spin_unlock(&parent->power.lock); 1383 1384 if (error) { 1385 status = RPM_SUSPENDED; 1386 goto out; 1387 } 1388 } 1389 1390 out_set: 1391 __update_runtime_status(dev, status); 1392 if (!error) 1393 dev->power.runtime_error = 0; 1394 1395 out: 1396 spin_unlock_irqrestore(&dev->power.lock, flags); 1397 1398 if (notify_parent) 1399 pm_request_idle(parent); 1400 1401 if (status == RPM_SUSPENDED) { 1402 int idx = device_links_read_lock(); 1403 1404 rpm_put_suppliers(dev); 1405 1406 device_links_read_unlock(idx); 1407 } 1408 1409 pm_runtime_enable(dev); 1410 1411 return error; 1412} 1413EXPORT_SYMBOL_GPL(__pm_runtime_set_status); 1414 1415/** 1416 * __pm_runtime_barrier - Cancel pending requests and wait for completions. 1417 * @dev: Device to handle. 1418 * 1419 * Flush all pending requests for the device from pm_wq and wait for all 1420 * runtime PM operations involving the device in progress to complete. 1421 * 1422 * Should be called under dev->power.lock with interrupts disabled. 1423 */ 1424static void __pm_runtime_barrier(struct device *dev) 1425{ 1426 pm_runtime_deactivate_timer(dev); 1427 1428 if (dev->power.request_pending) { 1429 dev->power.request = RPM_REQ_NONE; 1430 spin_unlock_irq(&dev->power.lock); 1431 1432 cancel_work_sync(&dev->power.work); 1433 1434 spin_lock_irq(&dev->power.lock); 1435 dev->power.request_pending = false; 1436 } 1437 1438 if (dev->power.runtime_status == RPM_SUSPENDING || 1439 dev->power.runtime_status == RPM_RESUMING || 1440 dev->power.idle_notification) { 1441 DEFINE_WAIT(wait); 1442 1443 /* Suspend, wake-up or idle notification in progress. */ 1444 for (;;) { 1445 prepare_to_wait(&dev->power.wait_queue, &wait, 1446 TASK_UNINTERRUPTIBLE); 1447 if (dev->power.runtime_status != RPM_SUSPENDING 1448 && dev->power.runtime_status != RPM_RESUMING 1449 && !dev->power.idle_notification) 1450 break; 1451 spin_unlock_irq(&dev->power.lock); 1452 1453 schedule(); 1454 1455 spin_lock_irq(&dev->power.lock); 1456 } 1457 finish_wait(&dev->power.wait_queue, &wait); 1458 } 1459} 1460 1461/** 1462 * pm_runtime_barrier - Flush pending requests and wait for completions. 1463 * @dev: Device to handle. 1464 * 1465 * Prevent the device from being suspended by incrementing its usage counter and 1466 * if there's a pending resume request for the device, wake the device up. 1467 * Next, make sure that all pending requests for the device have been flushed 1468 * from pm_wq and wait for all runtime PM operations involving the device in 1469 * progress to complete. 1470 */ 1471void pm_runtime_barrier(struct device *dev) 1472{ 1473 pm_runtime_get_noresume(dev); 1474 spin_lock_irq(&dev->power.lock); 1475 1476 if (dev->power.request_pending 1477 && dev->power.request == RPM_REQ_RESUME) 1478 rpm_resume(dev, 0); 1479 1480 __pm_runtime_barrier(dev); 1481 1482 spin_unlock_irq(&dev->power.lock); 1483 pm_runtime_put_noidle(dev); 1484} 1485EXPORT_SYMBOL_GPL(pm_runtime_barrier); 1486 1487bool pm_runtime_block_if_disabled(struct device *dev) 1488{ 1489 bool ret; 1490 1491 spin_lock_irq(&dev->power.lock); 1492 1493 ret = !pm_runtime_enabled(dev); 1494 if (ret && dev->power.last_status == RPM_INVALID) 1495 dev->power.last_status = RPM_BLOCKED; 1496 1497 spin_unlock_irq(&dev->power.lock); 1498 1499 return ret; 1500} 1501 1502void pm_runtime_unblock(struct device *dev) 1503{ 1504 spin_lock_irq(&dev->power.lock); 1505 1506 if (dev->power.last_status == RPM_BLOCKED) 1507 dev->power.last_status = RPM_INVALID; 1508 1509 spin_unlock_irq(&dev->power.lock); 1510} 1511 1512void __pm_runtime_disable(struct device *dev, bool check_resume) 1513{ 1514 spin_lock_irq(&dev->power.lock); 1515 1516 if (dev->power.disable_depth > 0) { 1517 dev->power.disable_depth++; 1518 goto out; 1519 } 1520 1521 /* 1522 * Wake up the device if there's a resume request pending, because that 1523 * means there probably is some I/O to process and disabling runtime PM 1524 * shouldn't prevent the device from processing the I/O. 1525 */ 1526 if (check_resume && dev->power.request_pending && 1527 dev->power.request == RPM_REQ_RESUME) { 1528 /* 1529 * Prevent suspends and idle notifications from being carried 1530 * out after we have woken up the device. 1531 */ 1532 pm_runtime_get_noresume(dev); 1533 1534 rpm_resume(dev, 0); 1535 1536 pm_runtime_put_noidle(dev); 1537 } 1538 1539 /* Update time accounting before disabling PM-runtime. */ 1540 update_pm_runtime_accounting(dev); 1541 1542 if (!dev->power.disable_depth++) { 1543 __pm_runtime_barrier(dev); 1544 dev->power.last_status = dev->power.runtime_status; 1545 } 1546 1547 out: 1548 spin_unlock_irq(&dev->power.lock); 1549} 1550EXPORT_SYMBOL_GPL(__pm_runtime_disable); 1551 1552/** 1553 * pm_runtime_enable - Enable runtime PM of a device. 1554 * @dev: Device to handle. 1555 */ 1556void pm_runtime_enable(struct device *dev) 1557{ 1558 unsigned long flags; 1559 1560 spin_lock_irqsave(&dev->power.lock, flags); 1561 1562 if (!dev->power.disable_depth) { 1563 dev_warn(dev, "Unbalanced %s!\n", __func__); 1564 goto out; 1565 } 1566 1567 if (--dev->power.disable_depth > 0) 1568 goto out; 1569 1570 if (dev->power.last_status == RPM_BLOCKED) { 1571 dev_warn(dev, "Attempt to enable runtime PM when it is blocked\n"); 1572 dump_stack(); 1573 } 1574 dev->power.last_status = RPM_INVALID; 1575 dev->power.accounting_timestamp = ktime_get_mono_fast_ns(); 1576 1577 if (dev->power.runtime_status == RPM_SUSPENDED && 1578 !dev->power.ignore_children && 1579 atomic_read(&dev->power.child_count) > 0) 1580 dev_warn(dev, "Enabling runtime PM for inactive device with active children\n"); 1581 1582out: 1583 spin_unlock_irqrestore(&dev->power.lock, flags); 1584} 1585EXPORT_SYMBOL_GPL(pm_runtime_enable); 1586 1587static void pm_runtime_set_suspended_action(void *data) 1588{ 1589 pm_runtime_set_suspended(data); 1590} 1591 1592/** 1593 * devm_pm_runtime_set_active_enabled - set_active version of devm_pm_runtime_enable. 1594 * 1595 * @dev: Device to handle. 1596 */ 1597int devm_pm_runtime_set_active_enabled(struct device *dev) 1598{ 1599 int err; 1600 1601 err = pm_runtime_set_active(dev); 1602 if (err) 1603 return err; 1604 1605 err = devm_add_action_or_reset(dev, pm_runtime_set_suspended_action, dev); 1606 if (err) 1607 return err; 1608 1609 return devm_pm_runtime_enable(dev); 1610} 1611EXPORT_SYMBOL_GPL(devm_pm_runtime_set_active_enabled); 1612 1613static void pm_runtime_disable_action(void *data) 1614{ 1615 pm_runtime_dont_use_autosuspend(data); 1616 pm_runtime_disable(data); 1617} 1618 1619/** 1620 * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable. 1621 * 1622 * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for 1623 * you at driver exit time if needed. 1624 * 1625 * @dev: Device to handle. 1626 */ 1627int devm_pm_runtime_enable(struct device *dev) 1628{ 1629 pm_runtime_enable(dev); 1630 1631 return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev); 1632} 1633EXPORT_SYMBOL_GPL(devm_pm_runtime_enable); 1634 1635static void pm_runtime_put_noidle_action(void *data) 1636{ 1637 pm_runtime_put_noidle(data); 1638} 1639 1640/** 1641 * devm_pm_runtime_get_noresume - devres-enabled version of pm_runtime_get_noresume. 1642 * 1643 * @dev: Device to handle. 1644 */ 1645int devm_pm_runtime_get_noresume(struct device *dev) 1646{ 1647 pm_runtime_get_noresume(dev); 1648 1649 return devm_add_action_or_reset(dev, pm_runtime_put_noidle_action, dev); 1650} 1651EXPORT_SYMBOL_GPL(devm_pm_runtime_get_noresume); 1652 1653/** 1654 * pm_runtime_forbid - Block runtime PM of a device. 1655 * @dev: Device to handle. 1656 * 1657 * Resume @dev if already suspended and block runtime suspend of @dev in such 1658 * a way that it can be unblocked via the /sys/devices/.../power/control 1659 * interface, or otherwise by calling pm_runtime_allow(). 1660 * 1661 * Calling this function many times in a row has the same effect as calling it 1662 * once. 1663 */ 1664void pm_runtime_forbid(struct device *dev) 1665{ 1666 spin_lock_irq(&dev->power.lock); 1667 if (!dev->power.runtime_auto) 1668 goto out; 1669 1670 dev->power.runtime_auto = false; 1671 atomic_inc(&dev->power.usage_count); 1672 rpm_resume(dev, 0); 1673 1674 out: 1675 spin_unlock_irq(&dev->power.lock); 1676} 1677EXPORT_SYMBOL_GPL(pm_runtime_forbid); 1678 1679/** 1680 * pm_runtime_allow - Unblock runtime PM of a device. 1681 * @dev: Device to handle. 1682 * 1683 * Unblock runtime suspend of @dev after it has been blocked by 1684 * pm_runtime_forbid() (for instance, if it has been blocked via the 1685 * /sys/devices/.../power/control interface), check if @dev can be 1686 * suspended and suspend it in that case. 1687 * 1688 * Calling this function many times in a row has the same effect as calling it 1689 * once. 1690 */ 1691void pm_runtime_allow(struct device *dev) 1692{ 1693 int ret; 1694 1695 spin_lock_irq(&dev->power.lock); 1696 if (dev->power.runtime_auto) 1697 goto out; 1698 1699 dev->power.runtime_auto = true; 1700 ret = rpm_drop_usage_count(dev); 1701 if (ret == 0) 1702 rpm_idle(dev, RPM_AUTO | RPM_ASYNC); 1703 else if (ret > 0) 1704 trace_rpm_usage(dev, RPM_AUTO | RPM_ASYNC); 1705 1706 out: 1707 spin_unlock_irq(&dev->power.lock); 1708} 1709EXPORT_SYMBOL_GPL(pm_runtime_allow); 1710 1711/** 1712 * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device. 1713 * @dev: Device to handle. 1714 * 1715 * Set the power.no_callbacks flag, which tells the PM core that this 1716 * device is power-managed through its parent and has no runtime PM 1717 * callbacks of its own. The runtime sysfs attributes will be removed. 1718 */ 1719void pm_runtime_no_callbacks(struct device *dev) 1720{ 1721 spin_lock_irq(&dev->power.lock); 1722 dev->power.no_callbacks = 1; 1723 spin_unlock_irq(&dev->power.lock); 1724 if (device_is_registered(dev)) 1725 rpm_sysfs_remove(dev); 1726} 1727EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks); 1728 1729/** 1730 * pm_runtime_irq_safe - Leave interrupts disabled during callbacks. 1731 * @dev: Device to handle 1732 * 1733 * Set the power.irq_safe flag, which tells the PM core that the 1734 * ->runtime_suspend() and ->runtime_resume() callbacks for this device should 1735 * always be invoked with the spinlock held and interrupts disabled. It also 1736 * causes the parent's usage counter to be permanently incremented, preventing 1737 * the parent from runtime suspending -- otherwise an irq-safe child might have 1738 * to wait for a non-irq-safe parent. 1739 */ 1740void pm_runtime_irq_safe(struct device *dev) 1741{ 1742 if (dev->parent) 1743 pm_runtime_get_sync(dev->parent); 1744 1745 spin_lock_irq(&dev->power.lock); 1746 dev->power.irq_safe = 1; 1747 spin_unlock_irq(&dev->power.lock); 1748} 1749EXPORT_SYMBOL_GPL(pm_runtime_irq_safe); 1750 1751/** 1752 * update_autosuspend - Handle a change to a device's autosuspend settings. 1753 * @dev: Device to handle. 1754 * @old_delay: The former autosuspend_delay value. 1755 * @old_use: The former use_autosuspend value. 1756 * 1757 * Prevent runtime suspend if the new delay is negative and use_autosuspend is 1758 * set; otherwise allow it. Send an idle notification if suspends are allowed. 1759 * 1760 * This function must be called under dev->power.lock with interrupts disabled. 1761 */ 1762static void update_autosuspend(struct device *dev, int old_delay, int old_use) 1763{ 1764 int delay = dev->power.autosuspend_delay; 1765 1766 /* Should runtime suspend be prevented now? */ 1767 if (dev->power.use_autosuspend && delay < 0) { 1768 1769 /* If it used to be allowed then prevent it. */ 1770 if (!old_use || old_delay >= 0) { 1771 atomic_inc(&dev->power.usage_count); 1772 rpm_resume(dev, 0); 1773 } else { 1774 trace_rpm_usage(dev, 0); 1775 } 1776 } 1777 1778 /* Runtime suspend should be allowed now. */ 1779 else { 1780 1781 /* If it used to be prevented then allow it. */ 1782 if (old_use && old_delay < 0) 1783 atomic_dec(&dev->power.usage_count); 1784 1785 /* Maybe we can autosuspend now. */ 1786 rpm_idle(dev, RPM_AUTO); 1787 } 1788} 1789 1790/** 1791 * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value. 1792 * @dev: Device to handle. 1793 * @delay: Value of the new delay in milliseconds. 1794 * 1795 * Set the device's power.autosuspend_delay value. If it changes to negative 1796 * and the power.use_autosuspend flag is set, prevent runtime suspends. If it 1797 * changes the other way, allow runtime suspends. 1798 */ 1799void pm_runtime_set_autosuspend_delay(struct device *dev, int delay) 1800{ 1801 int old_delay, old_use; 1802 1803 spin_lock_irq(&dev->power.lock); 1804 old_delay = dev->power.autosuspend_delay; 1805 old_use = dev->power.use_autosuspend; 1806 dev->power.autosuspend_delay = delay; 1807 update_autosuspend(dev, old_delay, old_use); 1808 spin_unlock_irq(&dev->power.lock); 1809} 1810EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay); 1811 1812/** 1813 * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag. 1814 * @dev: Device to handle. 1815 * @use: New value for use_autosuspend. 1816 * 1817 * Set the device's power.use_autosuspend flag, and allow or prevent runtime 1818 * suspends as needed. 1819 */ 1820void __pm_runtime_use_autosuspend(struct device *dev, bool use) 1821{ 1822 int old_delay, old_use; 1823 1824 spin_lock_irq(&dev->power.lock); 1825 old_delay = dev->power.autosuspend_delay; 1826 old_use = dev->power.use_autosuspend; 1827 dev->power.use_autosuspend = use; 1828 update_autosuspend(dev, old_delay, old_use); 1829 spin_unlock_irq(&dev->power.lock); 1830} 1831EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend); 1832 1833/** 1834 * pm_runtime_init - Initialize runtime PM fields in given device object. 1835 * @dev: Device object to initialize. 1836 */ 1837void pm_runtime_init(struct device *dev) 1838{ 1839 dev->power.runtime_status = RPM_SUSPENDED; 1840 dev->power.last_status = RPM_INVALID; 1841 dev->power.idle_notification = false; 1842 1843 dev->power.disable_depth = 1; 1844 atomic_set(&dev->power.usage_count, 0); 1845 1846 dev->power.runtime_error = 0; 1847 1848 atomic_set(&dev->power.child_count, 0); 1849 pm_suspend_ignore_children(dev, false); 1850 dev->power.runtime_auto = true; 1851 1852 dev->power.request_pending = false; 1853 dev->power.request = RPM_REQ_NONE; 1854 dev->power.deferred_resume = false; 1855 dev->power.needs_force_resume = false; 1856 INIT_WORK(&dev->power.work, pm_runtime_work); 1857 1858 dev->power.timer_expires = 0; 1859 hrtimer_setup(&dev->power.suspend_timer, pm_suspend_timer_fn, CLOCK_MONOTONIC, 1860 HRTIMER_MODE_ABS); 1861 1862 init_waitqueue_head(&dev->power.wait_queue); 1863} 1864 1865/** 1866 * pm_runtime_reinit - Re-initialize runtime PM fields in given device object. 1867 * @dev: Device object to re-initialize. 1868 */ 1869void pm_runtime_reinit(struct device *dev) 1870{ 1871 if (pm_runtime_enabled(dev)) 1872 return; 1873 1874 if (dev->power.runtime_status == RPM_ACTIVE) 1875 pm_runtime_set_suspended(dev); 1876 1877 if (dev->power.irq_safe) { 1878 spin_lock_irq(&dev->power.lock); 1879 dev->power.irq_safe = 0; 1880 spin_unlock_irq(&dev->power.lock); 1881 if (dev->parent) 1882 pm_runtime_put(dev->parent); 1883 } 1884 /* 1885 * Clear power.needs_force_resume in case it has been set by 1886 * pm_runtime_force_suspend() invoked from a driver remove callback. 1887 */ 1888 dev->power.needs_force_resume = false; 1889} 1890 1891/** 1892 * pm_runtime_remove - Prepare for removing a device from device hierarchy. 1893 * @dev: Device object being removed from device hierarchy. 1894 */ 1895void pm_runtime_remove(struct device *dev) 1896{ 1897 __pm_runtime_disable(dev, false); 1898 flush_work(&dev->power.work); 1899 pm_runtime_reinit(dev); 1900} 1901 1902/** 1903 * pm_runtime_get_suppliers - Resume and reference-count supplier devices. 1904 * @dev: Consumer device. 1905 */ 1906void pm_runtime_get_suppliers(struct device *dev) 1907{ 1908 struct device_link *link; 1909 int idx; 1910 1911 idx = device_links_read_lock(); 1912 1913 dev_for_each_link_to_supplier(link, dev) 1914 if (device_link_test(link, DL_FLAG_PM_RUNTIME)) { 1915 link->supplier_preactivated = true; 1916 pm_runtime_get_sync(link->supplier); 1917 } 1918 1919 device_links_read_unlock(idx); 1920} 1921 1922/** 1923 * pm_runtime_put_suppliers - Drop references to supplier devices. 1924 * @dev: Consumer device. 1925 */ 1926void pm_runtime_put_suppliers(struct device *dev) 1927{ 1928 struct device_link *link; 1929 int idx; 1930 1931 idx = device_links_read_lock(); 1932 1933 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, 1934 device_links_read_lock_held()) 1935 if (link->supplier_preactivated) { 1936 link->supplier_preactivated = false; 1937 pm_runtime_put(link->supplier); 1938 } 1939 1940 device_links_read_unlock(idx); 1941} 1942 1943void pm_runtime_new_link(struct device *dev) 1944{ 1945 spin_lock_irq(&dev->power.lock); 1946 dev->power.links_count++; 1947 spin_unlock_irq(&dev->power.lock); 1948} 1949 1950static void pm_runtime_drop_link_count(struct device *dev) 1951{ 1952 spin_lock_irq(&dev->power.lock); 1953 WARN_ON(dev->power.links_count == 0); 1954 dev->power.links_count--; 1955 spin_unlock_irq(&dev->power.lock); 1956} 1957 1958/** 1959 * pm_runtime_drop_link - Prepare for device link removal. 1960 * @link: Device link going away. 1961 * 1962 * Drop the link count of the consumer end of @link and decrement the supplier 1963 * device's runtime PM usage counter as many times as needed to drop all of the 1964 * PM runtime reference to it from the consumer. 1965 */ 1966void pm_runtime_drop_link(struct device_link *link) 1967{ 1968 if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) 1969 return; 1970 1971 pm_runtime_drop_link_count(link->consumer); 1972 pm_runtime_release_supplier(link); 1973 pm_request_idle(link->supplier); 1974} 1975 1976static pm_callback_t get_callback(struct device *dev, size_t cb_offset) 1977{ 1978 /* 1979 * Setting power.strict_midlayer means that the middle layer 1980 * code does not want its runtime PM callbacks to be invoked via 1981 * pm_runtime_force_suspend() and pm_runtime_force_resume(), so 1982 * return a direct pointer to the driver callback in that case. 1983 */ 1984 if (dev_pm_strict_midlayer_is_set(dev)) 1985 return __rpm_get_driver_callback(dev, cb_offset); 1986 1987 return __rpm_get_callback(dev, cb_offset); 1988} 1989 1990#define GET_CALLBACK(dev, callback) \ 1991 get_callback(dev, offsetof(struct dev_pm_ops, callback)) 1992 1993/** 1994 * pm_runtime_force_suspend - Force a device into suspend state if needed. 1995 * @dev: Device to suspend. 1996 * 1997 * Disable runtime PM so we safely can check the device's runtime PM status and 1998 * if it is active, invoke its ->runtime_suspend callback to suspend it and 1999 * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's 2000 * usage and children counters don't indicate that the device was in use before 2001 * the system-wide transition under way, decrement its parent's children counter 2002 * (if there is a parent). Keep runtime PM disabled to preserve the state 2003 * unless we encounter errors. 2004 * 2005 * Typically this function may be invoked from a system suspend callback to make 2006 * sure the device is put into low power state and it should only be used during 2007 * system-wide PM transitions to sleep states. It assumes that the analogous 2008 * pm_runtime_force_resume() will be used to resume the device. 2009 */ 2010int pm_runtime_force_suspend(struct device *dev) 2011{ 2012 int (*callback)(struct device *); 2013 int ret; 2014 2015 pm_runtime_disable(dev); 2016 if (pm_runtime_status_suspended(dev) || dev->power.needs_force_resume) 2017 return 0; 2018 2019 callback = GET_CALLBACK(dev, runtime_suspend); 2020 2021 dev_pm_enable_wake_irq_check(dev, true); 2022 ret = callback ? callback(dev) : 0; 2023 if (ret) 2024 goto err; 2025 2026 dev_pm_enable_wake_irq_complete(dev); 2027 2028 /* 2029 * If the device can stay in suspend after the system-wide transition 2030 * to the working state that will follow, drop the children counter of 2031 * its parent and the usage counters of its suppliers. Otherwise, set 2032 * power.needs_force_resume to let pm_runtime_force_resume() know that 2033 * the device needs to be taken care of and to prevent this function 2034 * from handling the device again in case the device is passed to it 2035 * once more subsequently. 2036 */ 2037 if (pm_runtime_need_not_resume(dev)) 2038 pm_runtime_set_suspended(dev); 2039 else 2040 dev->power.needs_force_resume = true; 2041 2042 return 0; 2043 2044err: 2045 dev_pm_disable_wake_irq_check(dev, true); 2046 pm_runtime_enable(dev); 2047 return ret; 2048} 2049EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); 2050 2051#ifdef CONFIG_PM_SLEEP 2052 2053/** 2054 * pm_runtime_force_resume - Force a device into resume state if needed. 2055 * @dev: Device to resume. 2056 * 2057 * This function expects that either pm_runtime_force_suspend() has put the 2058 * device into a low-power state prior to calling it, or the device had been 2059 * runtime-suspended before the preceding system-wide suspend transition and it 2060 * was left in suspend during that transition. 2061 * 2062 * The actions carried out by pm_runtime_force_suspend(), or by a runtime 2063 * suspend in general, are reversed and the device is brought back into full 2064 * power if it is expected to be used on system resume, which is the case when 2065 * its needs_force_resume flag is set or when its smart_suspend flag is set and 2066 * its runtime PM status is "active". 2067 * 2068 * In other cases, the resume is deferred to be managed via runtime PM. 2069 * 2070 * Typically, this function may be invoked from a system resume callback. 2071 */ 2072int pm_runtime_force_resume(struct device *dev) 2073{ 2074 int (*callback)(struct device *); 2075 int ret = 0; 2076 2077 if (!dev->power.needs_force_resume && (!dev_pm_smart_suspend(dev) || 2078 pm_runtime_status_suspended(dev))) 2079 goto out; 2080 2081 callback = GET_CALLBACK(dev, runtime_resume); 2082 2083 dev_pm_disable_wake_irq_check(dev, false); 2084 ret = callback ? callback(dev) : 0; 2085 if (ret) { 2086 pm_runtime_set_suspended(dev); 2087 dev_pm_enable_wake_irq_check(dev, false); 2088 goto out; 2089 } 2090 2091 pm_runtime_mark_last_busy(dev); 2092 2093out: 2094 /* 2095 * The smart_suspend flag can be cleared here because it is not going 2096 * to be necessary until the next system-wide suspend transition that 2097 * will update it again. 2098 */ 2099 dev->power.smart_suspend = false; 2100 /* 2101 * Also clear needs_force_resume to make this function skip devices that 2102 * have been seen by it once. 2103 */ 2104 dev->power.needs_force_resume = false; 2105 2106 pm_runtime_enable(dev); 2107 return ret; 2108} 2109EXPORT_SYMBOL_GPL(pm_runtime_force_resume); 2110 2111bool pm_runtime_need_not_resume(struct device *dev) 2112{ 2113 return atomic_read(&dev->power.usage_count) <= 1 && 2114 (atomic_read(&dev->power.child_count) == 0 || 2115 dev->power.ignore_children); 2116} 2117 2118#endif /* CONFIG_PM_SLEEP */
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