Lines Matching +full:device +full:- +full:level
5 (C) 2009-2011 Rafael J. Wysocki <[email protected]>, Novell Inc.
15 at the power management core (PM core) level by means of:
17 * The power management workqueue pm_wq in which bus types and device drivers can
18 put their PM-related work items. It is strongly recommended that pm_wq be
20 them to be synchronized with system-wide power transitions (suspend to RAM,
24 * A number of runtime PM fields in the 'power' member of 'struct device' (which
28 * Three device runtime PM callbacks in 'struct dev_pm_ops' (defined in
34 device drivers are encouraged to use these functions.
36 The runtime PM callbacks present in 'struct dev_pm_ops', the device runtime PM
40 2. Device Runtime PM Callbacks
43 There are three device runtime PM callbacks defined in 'struct dev_pm_ops'::
47 int (*runtime_suspend)(struct device *dev);
48 int (*runtime_resume)(struct device *dev);
49 int (*runtime_idle)(struct device *dev);
53 The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks
54 are executed by the PM core for the device's subsystem that may be either of
57 1. PM domain of the device, if the device's PM domain object, dev->pm_domain,
60 2. Device type of the device, if both dev->type and dev->type->pm are present.
62 3. Device class of the device, if both dev->class and dev->class->pm are
65 4. Bus type of the device, if both dev->bus and dev->bus->pm are present.
69 dev->driver->pm directly (if present).
72 priority order of callbacks from high to low is: PM domain, device type, class
73 and bus type. Moreover, the high-priority one will always take precedence over
74 a low-priority one. The PM domain, bus type, device type and class callbacks
75 are referred to as subsystem-level callbacks in what follows.
79 the PM core that it is safe to run the ->runtime_suspend(), ->runtime_resume()
80 and ->runtime_idle() callbacks for the given device in atomic context with
83 listed at the end of Section 4 may be used for that device within an interrupt
86 The subsystem-level suspend callback, if present, is _entirely_ _responsible_
87 for handling the suspend of the device as appropriate, which may, but need not
88 include executing the device driver's own ->runtime_suspend() callback (from the
89 PM core's point of view it is not necessary to implement a ->runtime_suspend()
90 callback in a device driver as long as the subsystem-level suspend callback
91 knows what to do to handle the device).
93 * Once the subsystem-level suspend callback (or the driver suspend callback,
94 if invoked directly) has completed successfully for the given device, the PM
95 core regards the device as suspended, which need not mean that it has been
97 device will not process data and will not communicate with the CPU(s) and
99 PM status of a device after successful execution of the suspend callback is
102 * If the suspend callback returns -EBUSY or -EAGAIN, the device's runtime PM
103 status remains 'active', which means that the device _must_ be fully
106 * If the suspend callback returns an error code different from -EBUSY and
107 -EAGAIN, the PM core regards this as a fatal error and will refuse to run
108 the helper functions described in Section 4 for the device until its status
113 mechanism allowing the device to request a change of its power state, such as
115 device, then ->runtime_suspend() should return -EBUSY. On the other hand, if
116 device_can_wakeup() returns 'true' for the device and the device is put into a
117 low-power state during the execution of the suspend callback, it is expected
118 that remote wakeup will be enabled for the device. Generally, remote wakeup
119 should be enabled for all input devices put into low-power states at run time.
121 The subsystem-level resume callback, if present, is **entirely responsible** for
122 handling the resume of the device as appropriate, which may, but need not
123 include executing the device driver's own ->runtime_resume() callback (from the
124 PM core's point of view it is not necessary to implement a ->runtime_resume()
125 callback in a device driver as long as the subsystem-level resume callback knows
126 what to do to handle the device).
128 * Once the subsystem-level resume callback (or the driver resume callback, if
129 invoked directly) has completed successfully, the PM core regards the device
130 as fully operational, which means that the device _must_ be able to complete
131 I/O operations as needed. The runtime PM status of the device is then
136 4 for the device, until its status is directly set to either 'active', or
140 The idle callback (a subsystem-level one, if present, or the driver one) is
141 executed by the PM core whenever the device appears to be idle, which is
142 indicated to the PM core by two counters, the device's usage counter and the
143 counter of 'active' children of the device.
148 idle callback with the device as its argument.
152 if the device can be suspended (i.e. if all of the conditions necessary for
153 suspending the device are satisfied) and to queue up a suspend request for the
154 device in that case. If there is no idle callback, or if the callback returns
155 0, then the PM core will attempt to carry out a runtime suspend of the device,
158 device last busy mark, pm_runtime_mark_last_busy(), to control the delay under
160 started a delayed suspend), the routine must return a non-zero value. Negative
165 one device:
168 ->runtime_suspend() in parallel with ->runtime_resume() or with another
169 instance of ->runtime_suspend() for the same device) with the exception that
170 ->runtime_suspend() or ->runtime_resume() can be executed in parallel with
171 ->runtime_idle() (although ->runtime_idle() will not be started while any
172 of the other callbacks is being executed for the same device).
174 (2) ->runtime_idle() and ->runtime_suspend() can only be executed for 'active'
175 devices (i.e. the PM core will only execute ->runtime_idle() or
176 ->runtime_suspend() for the devices the runtime PM status of which is
179 (3) ->runtime_idle() and ->runtime_suspend() can only be executed for a device
184 (4) ->runtime_resume() can only be executed for 'suspended' devices (i.e. the
185 PM core will only execute ->runtime_resume() for the devices the runtime
191 * If ->runtime_suspend() is about to be executed or there's a pending request
192 to execute it, ->runtime_idle() will not be executed for the same device.
194 * A request to execute or to schedule the execution of ->runtime_suspend()
195 will cancel any pending requests to execute ->runtime_idle() for the same
196 device.
198 * If ->runtime_resume() is about to be executed or there's a pending request
199 to execute it, the other callbacks will not be executed for the same device.
201 * A request to execute ->runtime_resume() will cancel any pending or
202 scheduled requests to execute the other callbacks for the same device,
205 3. Runtime PM Device Fields
208 The following device runtime PM fields are present in 'struct dev_pm_info', as
212 - timer used for scheduling (delayed) suspend and autosuspend requests
215 - timer expiration time, in jiffies (if this is different from zero, the
220 - work structure used for queuing up requests (i.e. work items in pm_wq)
223 - wait queue used if any of the helper functions needs to wait for another
227 - lock used for synchronization
230 - the usage counter of the device
233 - the count of 'active' children of the device
236 - if set, the value of child_count is ignored (but still updated)
239 - used for disabling the helper functions (they work normally if this is
244 - if set, there was a fatal error (one of the callbacks returned error code
250 - if set, ->runtime_idle() is being executed
253 - if set, there's a pending request (i.e. a work item queued up into pm_wq)
256 - type of request that's pending (valid if request_pending is set)
259 - set if ->runtime_resume() is about to be run while ->runtime_suspend() is
260 being executed for that device and it is not practical to wait for the
264 - the runtime PM status of the device; this field's initial value is
265 RPM_SUSPENDED, which means that each device is initially regarded by the
269 - the last runtime PM status of the device captured before disabling runtime
273 - if set, indicates that the user space has allowed the device driver to
274 power manage the device at run time via the /sys/devices/.../power/control
279 - indicates that the device does not use the runtime PM callbacks (see
284 - indicates that the ->runtime_suspend() and ->runtime_resume() callbacks
288 - indicates that the device's driver supports delayed autosuspend (see
293 - indicates that the PM core should attempt to carry out an autosuspend
297 - the delay time (in milliseconds) to be used for autosuspend
300 - the time (in jiffies) when the pm_runtime_mark_last_busy() helper
301 function was last called for this device; used in calculating inactivity
304 All of the above fields are members of the 'power' member of 'struct device'.
306 4. Runtime PM Device Helper Functions
312 `void pm_runtime_init(struct device *dev);`
313 - initialize the device runtime PM fields in 'struct dev_pm_info'
315 `void pm_runtime_remove(struct device *dev);`
316 - make sure that the runtime PM of the device will be disabled after
317 removing the device from device hierarchy
319 `int pm_runtime_idle(struct device *dev);`
320 - execute the subsystem-level idle callback for the device; returns an
321 error code on failure, where -EINPROGRESS means that ->runtime_idle() is
325 `int pm_runtime_suspend(struct device *dev);`
326 - execute the subsystem-level suspend callback for the device; returns 0 on
327 success, 1 if the device's runtime PM status was already 'suspended', or
328 error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt
329 to suspend the device again in future and -EACCES means that
332 `int pm_runtime_autosuspend(struct device *dev);`
333 - same as pm_runtime_suspend() except that the autosuspend delay is taken
338 `int pm_runtime_resume(struct device *dev);`
339 - execute the subsystem-level resume callback for the device; returns 0 on
340 success, 1 if the device's runtime PM status is already 'active' (also if
342 changing from 0 to 1) or error code on failure, where -EAGAIN means it may
343 be safe to attempt to resume the device again in future, but
344 'power.runtime_error' should be checked additionally, and -EACCES means
348 `int pm_runtime_resume_and_get(struct device *dev);`
349 - run pm_runtime_resume(dev) and if successful, increment the device's
350 usage counter; returns 0 on success (whether or not the device's
354 `int pm_request_idle(struct device *dev);`
355 - submit a request to execute the subsystem-level idle callback for the
356 device (the request is represented by a work item in pm_wq); returns 0 on
359 `int pm_request_autosuspend(struct device *dev);`
360 - schedule the execution of the subsystem-level suspend callback for the
361 device when the autosuspend delay has expired; if the delay has already
364 `int pm_schedule_suspend(struct device *dev, unsigned int delay);`
365 - schedule the execution of the subsystem-level suspend callback for the
366 device in future, where 'delay' is the time to wait before queuing up a
368 item is queued up immediately); returns 0 on success, 1 if the device's PM
371 ->runtime_suspend() is already scheduled and not yet expired, the new
374 `int pm_request_resume(struct device *dev);`
375 - submit a request to execute the subsystem-level resume callback for the
376 device (the request is represented by a work item in pm_wq); returns 0 on
377 success, 1 if the device's runtime PM status was already 'active', or
380 `void pm_runtime_get_noresume(struct device *dev);`
381 - increment the device's usage counter
383 `int pm_runtime_get(struct device *dev);`
384 - increment the device's usage counter, run pm_request_resume(dev) and
387 `int pm_runtime_get_sync(struct device *dev);`
388 - increment the device's usage counter, run pm_runtime_resume(dev) and
390 note that it does not drop the device's usage counter on errors, so
395 `int pm_runtime_get_if_in_use(struct device *dev);`
396 - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
401 `int pm_runtime_get_if_active(struct device *dev);`
402 - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
406 `void pm_runtime_put_noidle(struct device *dev);`
407 - decrement the device's usage counter
409 `int pm_runtime_put(struct device *dev);`
410 - decrement the device's usage counter; if the result is 0 then run
413 `int pm_runtime_put_autosuspend(struct device *dev);`
414 - does the same as __pm_runtime_put_autosuspend() for now, but in the
417 `int __pm_runtime_put_autosuspend(struct device *dev);`
418 - decrement the device's usage counter; if the result is 0 then run
421 `int pm_runtime_put_sync(struct device *dev);`
422 - decrement the device's usage counter; if the result is 0 then run
425 `int pm_runtime_put_sync_suspend(struct device *dev);`
426 - decrement the device's usage counter; if the result is 0 then run
429 `int pm_runtime_put_sync_autosuspend(struct device *dev);`
430 - decrement the device's usage counter; if the result is 0 then run
433 `void pm_runtime_enable(struct device *dev);`
434 - decrement the device's 'power.disable_depth' field; if that field is equal
435 to zero, the runtime PM helper functions can execute subsystem-level
436 callbacks described in Section 2 for the device
438 `int pm_runtime_disable(struct device *dev);`
439 - increment the device's 'power.disable_depth' field (if the value of that
440 field was previously zero, this prevents subsystem-level runtime PM
441 callbacks from being run for the device), make sure that all of the
442 pending runtime PM operations on the device are either completed or
444 necessary to execute the subsystem-level resume callback for the device
447 `int pm_runtime_barrier(struct device *dev);`
448 - check if there's a resume request pending for the device and resume it
452 necessary to execute the subsystem-level resume callback for the device to
455 `void pm_suspend_ignore_children(struct device *dev, bool enable);`
456 - set/unset the power.ignore_children flag of the device
458 `int pm_runtime_set_active(struct device *dev);`
459 - clear the device's 'power.runtime_error' flag, set the device's runtime
463 zero); it will fail and return error code if the device has a parent
466 `void pm_runtime_set_suspended(struct device *dev);`
467 - clear the device's 'power.runtime_error' flag, set the device's runtime
473 `bool pm_runtime_active(struct device *dev);`
474 - return true if the device's runtime PM status is 'active' or its
477 `bool pm_runtime_suspended(struct device *dev);`
478 - return true if the device's runtime PM status is 'suspended' and its
481 `bool pm_runtime_status_suspended(struct device *dev);`
482 - return true if the device's runtime PM status is 'suspended'
484 `void pm_runtime_allow(struct device *dev);`
485 - set the power.runtime_auto flag for the device and decrease its usage
487 effectively allow the device to be power managed at run time)
489 `void pm_runtime_forbid(struct device *dev);`
490 - unset the power.runtime_auto flag for the device and increase its usage
492 effectively prevent the device from being power managed at run time)
494 `void pm_runtime_no_callbacks(struct device *dev);`
495 - set the power.no_callbacks flag for the device and remove the runtime
497 added when the device is registered)
499 `void pm_runtime_irq_safe(struct device *dev);`
500 - set the power.irq_safe flag for the device, causing the runtime-PM
503 `bool pm_runtime_is_irq_safe(struct device *dev);`
504 - return true if power.irq_safe flag was set for the device, causing
505 the runtime-PM callbacks to be invoked with interrupts off
507 `void pm_runtime_mark_last_busy(struct device *dev);`
508 - set the power.last_busy field to the current time
510 `void pm_runtime_use_autosuspend(struct device *dev);`
511 - set the power.use_autosuspend flag, enabling autosuspend delays; call
515 `void pm_runtime_dont_use_autosuspend(struct device *dev);`
516 - clear the power.use_autosuspend flag, disabling autosuspend delays;
517 decrement the device's usage counter if the flag was previously set and
520 `void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);`
521 - set the power.autosuspend_delay value to 'delay' (expressed in
524 called or the device's usage counter may be decremented and
529 `unsigned long pm_runtime_autosuspend_expiration(struct device *dev);`
530 - calculate the time when the current autosuspend delay period will expire,
539 - pm_request_idle()
540 - pm_request_autosuspend()
541 - pm_schedule_suspend()
542 - pm_request_resume()
543 - pm_runtime_get_noresume()
544 - pm_runtime_get()
545 - pm_runtime_put_noidle()
546 - pm_runtime_put()
547 - pm_runtime_put_autosuspend()
548 - __pm_runtime_put_autosuspend()
549 - pm_runtime_enable()
550 - pm_suspend_ignore_children()
551 - pm_runtime_set_active()
552 - pm_runtime_set_suspended()
553 - pm_runtime_suspended()
554 - pm_runtime_mark_last_busy()
555 - pm_runtime_autosuspend_expiration()
557 If pm_runtime_irq_safe() has been called for a device then the following helper
560 - pm_runtime_idle()
561 - pm_runtime_suspend()
562 - pm_runtime_autosuspend()
563 - pm_runtime_resume()
564 - pm_runtime_get_sync()
565 - pm_runtime_put_sync()
566 - pm_runtime_put_sync_suspend()
567 - pm_runtime_put_sync_autosuspend()
569 5. Runtime PM Initialization, Device Probing and Removal
574 -EAGAIN until pm_runtime_enable() is called for the device.
577 'suspended', but it need not reflect the actual physical state of the device.
578 Thus, if the device is initially active (i.e. it is able to process I/O), its
580 pm_runtime_set_active(), before pm_runtime_enable() is called for the device.
582 However, if the device has a parent and the parent's runtime PM is enabled,
583 calling pm_runtime_set_active() for the device will affect the parent, unless
589 once pm_runtime_set_active() has been called for the device, pm_runtime_enable()
594 If the default initial runtime PM status of the device (i.e. 'suspended')
595 reflects the actual state of the device, its bus type's or its driver's
596 ->probe() callback will likely need to wake it up using one of the PM core's
598 should be used. Of course, for this purpose the device's runtime PM has to be
601 Note, if the device may execute pm_runtime calls during the probe (such as
604 appropriate to ensure that the device is not put back to sleep during the
605 probe. This can happen with systems such as the network device layer.
607 It may be desirable to suspend the device once ->probe() has finished.
609 request to execute the subsystem-level idle callback for the device at that
611 update the last busy mark before returning from ->probe().
618 resumes the device if it's in the suspended state and prevents it from
622 calling pm_runtime_suspend() from their ->remove() routines, the driver core
625 drivers to make their ->remove() callbacks avoid races with runtime PM directly,
629 Drivers in ->remove() callback should undo the runtime PM changes done
630 in ->probe(). Usually this means calling pm_runtime_disable(),
633 The user space can effectively disallow the driver of the device to power manage
637 runtime power management of the device until the user space turns it on.
639 status of the device is 'active' and call pm_runtime_forbid(). It should be
642 manage the device at run time, the driver may confuse it by using
649 as suspend-to-RAM and suspend-to-disk) interact with each other in a couple of
650 ways. If a device is active when a system sleep starts, everything is
651 straightforward. But what should happen if the device is already suspended?
653 The device may have different wake-up settings for runtime PM and system sleep.
654 For example, remote wake-up may be enabled for runtime suspend but disallowed
656 the subsystem-level system suspend callback is responsible for changing the
657 device's wake-up setting (it may leave that to the device driver's system
658 suspend routine). It may be necessary to resume the device and suspend it again
666 * The device might need to switch power levels, wake-up settings, etc.
668 * Remote wake-up events might have been lost by the firmware.
670 * The device's children may need the device to be at full power in order
673 * The driver's idea of the device state may not agree with the device's
676 * The device might need to be reset.
678 * Even though the device was suspended, if its usage counter was > 0 then most
681 If the device had been suspended before the system suspend began and it's
683 to be updated to reflect the actual post-system sleep status. The way to do
686 - pm_runtime_disable(dev);
687 - pm_runtime_set_active(dev);
688 - pm_runtime_enable(dev);
691 ->suspend() callback and decrements it after calling the ->resume() callback.
694 following the return of the ->resume() callback, the ->runtime_idle() callback
698 or hardware operation. Instead, all hardware components are put into low-power
710 different levels of device hierarchy. Namely, if a system suspend .prepare()
711 callback returns a positive number for a device, that indicates to the PM core
712 that the device appears to be runtime-suspended and its state is fine, so it
716 .complete() callback, which is then entirely responsible for handling the device
718 related to hibernation (see Documentation/driver-api/pm/devices.rst for more
725 * During system suspend pm_runtime_get_noresume() is called for every device
726 right before executing the subsystem-level .prepare() callback for it and
727 pm_runtime_barrier() is called for every device right before executing the
728 subsystem-level .suspend() callback for it. In addition to that the PM core
730 device right before executing the subsystem-level .suspend_late() callback
734 every device right after executing the subsystem-level .resume_early()
735 callback and right after executing the subsystem-level .complete() callback
745 `int pm_generic_runtime_suspend(struct device *dev);`
746 - invoke the ->runtime_suspend() callback provided by the driver of this
747 device and return its result, or return 0 if not defined
749 `int pm_generic_runtime_resume(struct device *dev);`
750 - invoke the ->runtime_resume() callback provided by the driver of this
751 device and return its result, or return 0 if not defined
753 `int pm_generic_suspend(struct device *dev);`
754 - if the device has not been suspended at run time, invoke the ->suspend()
758 `int pm_generic_suspend_noirq(struct device *dev);`
759 - if pm_runtime_suspended(dev) returns "false", invoke the ->suspend_noirq()
760 callback provided by the device's driver and return its result, or return
763 `int pm_generic_resume(struct device *dev);`
764 - invoke the ->resume() callback provided by the driver of this device and,
765 if successful, change the device's runtime PM status to 'active'
767 `int pm_generic_resume_noirq(struct device *dev);`
768 - invoke the ->resume_noirq() callback provided by the driver of this device
770 `int pm_generic_freeze(struct device *dev);`
771 - if the device has not been suspended at run time, invoke the ->freeze()
775 `int pm_generic_freeze_noirq(struct device *dev);`
776 - if pm_runtime_suspended(dev) returns "false", invoke the ->freeze_noirq()
777 callback provided by the device's driver and return its result, or return
780 `int pm_generic_thaw(struct device *dev);`
781 - if the device has not been suspended at run time, invoke the ->thaw()
785 `int pm_generic_thaw_noirq(struct device *dev);`
786 - if pm_runtime_suspended(dev) returns "false", invoke the ->thaw_noirq()
787 callback provided by the device's driver and return its result, or return
790 `int pm_generic_poweroff(struct device *dev);`
791 - if the device has not been suspended at run time, invoke the ->poweroff()
795 `int pm_generic_poweroff_noirq(struct device *dev);`
796 - if pm_runtime_suspended(dev) returns "false", run the ->poweroff_noirq()
797 callback provided by the device's driver and return its result, or return
800 `int pm_generic_restore(struct device *dev);`
801 - invoke the ->restore() callback provided by the driver of this device and,
802 if successful, change the device's runtime PM status to 'active'
804 `int pm_generic_restore_noirq(struct device *dev);`
805 - invoke the ->restore_noirq() callback provided by the device's driver
808 provide its own callbacks for ->runtime_idle(), ->runtime_suspend(),
809 ->runtime_resume(), ->suspend(), ->suspend_noirq(), ->resume(),
810 ->resume_noirq(), ->freeze(), ->freeze_noirq(), ->thaw(), ->thaw_noirq(),
811 ->poweroff(), ->poweroff_noirq(), ->restore(), ->restore_noirq() in the
812 subsystem-level dev_pm_ops structure.
814 Device drivers that wish to use the same function as a system suspend, freeze,
820 8. "No-Callback" Devices
823 Some "devices" are only logical sub-devices of their parent and cannot be
824 power-managed on their own. (The prototype example is a USB interface. Entire
825 USB devices can go into low-power mode or send wake-up requests, but neither is
827 need of runtime PM callbacks; if the callbacks did exist, ->runtime_suspend()
828 and ->runtime_resume() would always return 0 without doing anything else and
829 ->runtime_idle() would always call pm_runtime_suspend().
832 pm_runtime_no_callbacks(). This should be done after the device structure is
833 initialized and before it is registered (although after device registration is
834 also okay). The routine will set the device's power.no_callbacks flag and
835 prevent the non-debugging runtime PM sysfs attributes from being created.
838 ->runtime_idle(), ->runtime_suspend(), or ->runtime_resume() callbacks.
842 As a consequence, the PM core will never directly inform the device's subsystem
843 or driver about runtime power changes. Instead, the driver for the device's
844 parent must take responsibility for telling the device's driver when the
850 domain could get attached to the device or that the device is power managed
851 through a supplier device link. For these reasons and to avoid boilerplate code
856 9. Autosuspend, or automatically-delayed suspends
859 Changing a device's power state isn't free; it requires both time and energy.
860 A device should be put in a low-power state only when there's some reason to
862 says that a device which hasn't been used for a while is liable to remain
865 the heuristic ends up being non-optimal, it will still prevent devices from
866 "bouncing" too rapidly between low-power and full-power states.
869 device is automatically suspended (the subsystem or driver still has to call
877 length initially by calling pm_runtime_set_autosuspend_delay(), but after device
882 pm_runtime_use_autosuspend() (preferably before registering the device), and
884 instead of the non-autosuspend counterparts::
891 Drivers may also continue to use the non-autosuspend helper functions; they
895 Under some circumstances a driver or subsystem may want to prevent a device
897 autosuspend delay time has expired. If the ->runtime_suspend() callback
898 returns -EAGAIN or -EBUSY, and if the next autosuspend delay expiration time is
901 autosuspend. The ->runtime_suspend() callback can't do this rescheduling
902 itself because no suspend requests of any kind are accepted while the device is
907 synchronize ->runtime_suspend() callbacks with the arrival of I/O requests.
909 Here is a schematic pseudo-code example::
913 lock(&foo->private_lock);
915 if (foo->num_pending_requests++ == 0)
916 pm_runtime_get(&foo->dev);
917 if (!foo->is_suspended)
919 unlock(&foo->private_lock);
924 lock(&foo->private_lock);
925 if (--foo->num_pending_requests == 0) {
926 pm_runtime_mark_last_busy(&foo->dev);
927 __pm_runtime_put_autosuspend(&foo->dev);
931 unlock(&foo->private_lock);
935 int foo_runtime_suspend(struct device *dev)
940 lock(&foo->private_lock);
941 if (foo->num_pending_requests > 0) {
942 ret = -EBUSY;
944 /* ... suspend the device ... */
945 foo->is_suspended = 1;
947 unlock(&foo->private_lock);
951 int foo_runtime_resume(struct device *dev)
955 lock(&foo->private_lock);
956 /* ... resume the device ... */
957 foo->is_suspended = 0;
958 pm_runtime_mark_last_busy(&foo->dev);
959 if (foo->num_pending_requests > 0)
961 unlock(&foo->private_lock);
973 pm_runtime_autosuspend_expiration() from within the ->runtime_suspend()
976 -EAGAIN.