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Merge branch 'pm-runtime' into for-linus 

* pm-runtime:
  OMAP: PM: disable idle on suspend for GPIO and UART
  OMAP: PM: omap_device: add API to disable idle on suspend
  OMAP: PM: omap_device: add system PM methods for PM domain handling
  OMAP: PM: omap_device: conditionally use PM domain runtime helpers
  PM / Runtime: Add new helper function: pm_runtime_status_suspended()
  PM / Runtime: Consistent utilization of deferred_resume
  PM / Runtime: Prevent runtime_resume from racing with probe
  PM / Runtime: Replace "run-time" with "runtime" in documentation
  PM / Runtime: Improve documentation of enable, disable and barrier
  PM: Limit race conditions between runtime PM and system sleep (v2)
  PCI / PM: Detect early wakeup in pci_pm_prepare()
  PM / Runtime: Return special error code if runtime PM is disabled
  PM / Runtime: Update documentation of interactions with system sleep
This commit is contained in:
Rafael J. Wysocki 2011-07-15 23:59:25 +02:00
parent ba1389d74f c8c9fda506
commit 7ae033cc0d
12 changed files with 277 additions and 137 deletions
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6
Documentation/power/devices.txt
View File

@ -604,7 +604,7 @@ state temporarily, for example so that its system wakeup capability can be
disabled. This all depends on the hardware and the design of the subsystem and disabled. This all depends on the hardware and the design of the subsystem and
device driver in question. device driver in question.
During system-wide resume from a sleep state it's best to put devices into the During system-wide resume from a sleep state it's easiest to put devices into
full-power state, as explained in Documentation/power/runtime_pm.txt. Refer to the full-power state, as explained in Documentation/power/runtime_pm.txt. Refer
that document for more information regarding this particular issue as well as to that document for more information regarding this particular issue as well as
for information on the device runtime power management framework in general. for information on the device runtime power management framework in general.

197
Documentation/power/runtime_pm.txt
View File

@ -1,39 +1,39 @@
Run-time Power Management Framework for I/O Devices Runtime Power Management Framework for I/O Devices
(C) 2009-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. (C) 2009-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
(C) 2010 Alan Stern <stern@rowland.harvard.edu> (C) 2010 Alan Stern <stern@rowland.harvard.edu>
1. Introduction 1. Introduction
Support for run-time power management (run-time PM) of I/O devices is provided Support for runtime power management (runtime PM) of I/O devices is provided
at the power management core (PM core) level by means of: at the power management core (PM core) level by means of:
* The power management workqueue pm_wq in which bus types and device drivers can * The power management workqueue pm_wq in which bus types and device drivers can
put their PM-related work items. It is strongly recommended that pm_wq be put their PM-related work items. It is strongly recommended that pm_wq be
used for queuing all work items related to run-time PM, because this allows used for queuing all work items related to runtime PM, because this allows
them to be synchronized with system-wide power transitions (suspend to RAM, them to be synchronized with system-wide power transitions (suspend to RAM,
hibernation and resume from system sleep states). pm_wq is declared in hibernation and resume from system sleep states). pm_wq is declared in
include/linux/pm_runtime.h and defined in kernel/power/main.c. include/linux/pm_runtime.h and defined in kernel/power/main.c.
* A number of run-time PM fields in the 'power' member of 'struct device' (which * A number of runtime PM fields in the 'power' member of 'struct device' (which
is of the type 'struct dev_pm_info', defined in include/linux/pm.h) that can is of the type 'struct dev_pm_info', defined in include/linux/pm.h) that can
be used for synchronizing run-time PM operations with one another. be used for synchronizing runtime PM operations with one another.
* Three device run-time PM callbacks in 'struct dev_pm_ops' (defined in * Three device runtime PM callbacks in 'struct dev_pm_ops' (defined in
include/linux/pm.h). include/linux/pm.h).
* A set of helper functions defined in drivers/base/power/runtime.c that can be * A set of helper functions defined in drivers/base/power/runtime.c that can be
used for carrying out run-time PM operations in such a way that the used for carrying out runtime PM operations in such a way that the
synchronization between them is taken care of by the PM core. Bus types and synchronization between them is taken care of by the PM core. Bus types and
device drivers are encouraged to use these functions. device drivers are encouraged to use these functions.
The run-time PM callbacks present in 'struct dev_pm_ops', the device run-time PM The runtime PM callbacks present in 'struct dev_pm_ops', the device runtime PM
fields of 'struct dev_pm_info' and the core helper functions provided for fields of 'struct dev_pm_info' and the core helper functions provided for
run-time PM are described below. runtime PM are described below.
2. Device Run-time PM Callbacks 2. Device Runtime PM Callbacks
There are three device run-time PM callbacks defined in 'struct dev_pm_ops': There are three device runtime PM callbacks defined in 'struct dev_pm_ops':
struct dev_pm_ops { struct dev_pm_ops {
... ...
@ -72,11 +72,11 @@ knows what to do to handle the device).
not mean that the device has been put into a low power state. It is not mean that the device has been put into a low power state. It is
supposed to mean, however, that the device will not process data and will supposed to mean, however, that the device will not process data and will
not communicate with the CPU(s) and RAM until the subsystem-level resume not communicate with the CPU(s) and RAM until the subsystem-level resume
callback is executed for it. The run-time PM status of a device after callback is executed for it. The runtime PM status of a device after
successful execution of the subsystem-level suspend callback is 'suspended'. successful execution of the subsystem-level suspend callback is 'suspended'.
* If the subsystem-level suspend callback returns -EBUSY or -EAGAIN, * If the subsystem-level suspend callback returns -EBUSY or -EAGAIN,
the device's run-time PM status is 'active', which means that the device the device's runtime PM status is 'active', which means that the device
_must_ be fully operational afterwards. _must_ be fully operational afterwards.
* If the subsystem-level suspend callback returns an error code different * If the subsystem-level suspend callback returns an error code different
@ -104,7 +104,7 @@ the device).
* Once the subsystem-level resume callback has completed successfully, the PM * Once the subsystem-level resume callback has completed successfully, the PM
core regards the device as fully operational, which means that the device core regards the device as fully operational, which means that the device
_must_ be able to complete I/O operations as needed. The run-time PM status _must_ be able to complete I/O operations as needed. The runtime PM status
of the device is then 'active'. of the device is then 'active'.
* If the subsystem-level resume callback returns an error code, the PM core * If the subsystem-level resume callback returns an error code, the PM core
@ -130,7 +130,7 @@ device in that case. The value returned by this callback is ignored by the PM
core. core.
The helper functions provided by the PM core, described in Section 4, guarantee The helper functions provided by the PM core, described in Section 4, guarantee
that the following constraints are met with respect to the bus type's run-time that the following constraints are met with respect to the bus type's runtime
PM callbacks: PM callbacks:
(1) The callbacks are mutually exclusive (e.g. it is forbidden to execute (1) The callbacks are mutually exclusive (e.g. it is forbidden to execute
@ -142,7 +142,7 @@ PM callbacks:
(2) ->runtime_idle() and ->runtime_suspend() can only be executed for 'active' (2) ->runtime_idle() and ->runtime_suspend() can only be executed for 'active'
devices (i.e. the PM core will only execute ->runtime_idle() or devices (i.e. the PM core will only execute ->runtime_idle() or
->runtime_suspend() for the devices the run-time PM status of which is ->runtime_suspend() for the devices the runtime PM status of which is
'active'). 'active').
(3) ->runtime_idle() and ->runtime_suspend() can only be executed for a device (3) ->runtime_idle() and ->runtime_suspend() can only be executed for a device
@ -151,7 +151,7 @@ PM callbacks:
flag of which is set. flag of which is set.
(4) ->runtime_resume() can only be executed for 'suspended' devices (i.e. the (4) ->runtime_resume() can only be executed for 'suspended' devices (i.e. the
PM core will only execute ->runtime_resume() for the devices the run-time PM core will only execute ->runtime_resume() for the devices the runtime
PM status of which is 'suspended'). PM status of which is 'suspended').
Additionally, the helper functions provided by the PM core obey the following Additionally, the helper functions provided by the PM core obey the following
@ -171,9 +171,9 @@ rules:
scheduled requests to execute the other callbacks for the same device, scheduled requests to execute the other callbacks for the same device,
except for scheduled autosuspends. except for scheduled autosuspends.
3. Run-time PM Device Fields 3. Runtime PM Device Fields
The following device run-time PM fields are present in 'struct dev_pm_info', as The following device runtime PM fields are present in 'struct dev_pm_info', as
defined in include/linux/pm.h: defined in include/linux/pm.h:
struct timer_list suspend_timer; struct timer_list suspend_timer;
@ -205,7 +205,7 @@ defined in include/linux/pm.h:
unsigned int disable_depth; unsigned int disable_depth;
- used for disabling the helper funcions (they work normally if this is - used for disabling the helper funcions (they work normally if this is
equal to zero); the initial value of it is 1 (i.e. run-time PM is equal to zero); the initial value of it is 1 (i.e. runtime PM is
initially disabled for all devices) initially disabled for all devices)
unsigned int runtime_error; unsigned int runtime_error;
@ -229,10 +229,10 @@ defined in include/linux/pm.h:
suspend to complete; means "start a resume as soon as you've suspended" suspend to complete; means "start a resume as soon as you've suspended"
unsigned int run_wake; unsigned int run_wake;
- set if the device is capable of generating run-time wake-up events - set if the device is capable of generating runtime wake-up events
enum rpm_status runtime_status; enum rpm_status runtime_status;
- the run-time PM status of the device; this field's initial value is - the runtime PM status of the device; this field's initial value is
RPM_SUSPENDED, which means that each device is initially regarded by the RPM_SUSPENDED, which means that each device is initially regarded by the
PM core as 'suspended', regardless of its real hardware status PM core as 'suspended', regardless of its real hardware status
@ -243,7 +243,7 @@ defined in include/linux/pm.h:
and pm_runtime_forbid() helper functions and pm_runtime_forbid() helper functions
unsigned int no_callbacks; unsigned int no_callbacks;
- indicates that the device does not use the run-time PM callbacks (see - indicates that the device does not use the runtime PM callbacks (see
Section 8); it may be modified only by the pm_runtime_no_callbacks() Section 8); it may be modified only by the pm_runtime_no_callbacks()
helper function helper function
@ -270,16 +270,16 @@ defined in include/linux/pm.h:
All of the above fields are members of the 'power' member of 'struct device'. All of the above fields are members of the 'power' member of 'struct device'.
4. Run-time PM Device Helper Functions 4. Runtime PM Device Helper Functions
The following run-time PM helper functions are defined in The following runtime PM helper functions are defined in
drivers/base/power/runtime.c and include/linux/pm_runtime.h: drivers/base/power/runtime.c and include/linux/pm_runtime.h:
void pm_runtime_init(struct device *dev); void pm_runtime_init(struct device *dev);
- initialize the device run-time PM fields in 'struct dev_pm_info' - initialize the device runtime PM fields in 'struct dev_pm_info'
void pm_runtime_remove(struct device *dev); void pm_runtime_remove(struct device *dev);
- make sure that the run-time PM of the device will be disabled after - make sure that the runtime PM of the device will be disabled after
removing the device from device hierarchy removing the device from device hierarchy
int pm_runtime_idle(struct device *dev); int pm_runtime_idle(struct device *dev);
@ -289,9 +289,10 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
int pm_runtime_suspend(struct device *dev); int pm_runtime_suspend(struct device *dev);
- execute the subsystem-level suspend callback for the device; returns 0 on - execute the subsystem-level suspend callback for the device; returns 0 on
success, 1 if the device's run-time PM status was already 'suspended', or success, 1 if the device's runtime PM status was already 'suspended', or
error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt
to suspend the device again in future to suspend the device again in future and -EACCES means that
'power.disable_depth' is different from 0
int pm_runtime_autosuspend(struct device *dev); int pm_runtime_autosuspend(struct device *dev);
- same as pm_runtime_suspend() except that the autosuspend delay is taken - same as pm_runtime_suspend() except that the autosuspend delay is taken
@ -301,10 +302,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
int pm_runtime_resume(struct device *dev); int pm_runtime_resume(struct device *dev);
- execute the subsystem-level resume callback for the device; returns 0 on - execute the subsystem-level resume callback for the device; returns 0 on
success, 1 if the device's run-time PM status was already 'active' or success, 1 if the device's runtime PM status was already 'active' or
error code on failure, where -EAGAIN means it may be safe to attempt to error code on failure, where -EAGAIN means it may be safe to attempt to
resume the device again in future, but 'power.runtime_error' should be resume the device again in future, but 'power.runtime_error' should be
checked additionally checked additionally, and -EACCES means that 'power.disable_depth' is
different from 0
int pm_request_idle(struct device *dev); int pm_request_idle(struct device *dev);
- submit a request to execute the subsystem-level idle callback for the - submit a request to execute the subsystem-level idle callback for the
@ -321,7 +323,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
device in future, where 'delay' is the time to wait before queuing up a device in future, where 'delay' is the time to wait before queuing up a
suspend work item in pm_wq, in milliseconds (if 'delay' is zero, the work suspend work item in pm_wq, in milliseconds (if 'delay' is zero, the work
item is queued up immediately); returns 0 on success, 1 if the device's PM item is queued up immediately); returns 0 on success, 1 if the device's PM
run-time status was already 'suspended', or error code if the request runtime status was already 'suspended', or error code if the request
hasn't been scheduled (or queued up if 'delay' is 0); if the execution of hasn't been scheduled (or queued up if 'delay' is 0); if the execution of
->runtime_suspend() is already scheduled and not yet expired, the new ->runtime_suspend() is already scheduled and not yet expired, the new
value of 'delay' will be used as the time to wait value of 'delay' will be used as the time to wait
@ -329,7 +331,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
int pm_request_resume(struct device *dev); int pm_request_resume(struct device *dev);
- submit a request to execute the subsystem-level resume callback for the - submit a request to execute the subsystem-level resume callback for the
device (the request is represented by a work item in pm_wq); returns 0 on device (the request is represented by a work item in pm_wq); returns 0 on
success, 1 if the device's run-time PM status was already 'active', or success, 1 if the device's runtime PM status was already 'active', or
error code if the request hasn't been queued up error code if the request hasn't been queued up
void pm_runtime_get_noresume(struct device *dev); void pm_runtime_get_noresume(struct device *dev);
@ -367,22 +369,32 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
pm_runtime_autosuspend(dev) and return its result pm_runtime_autosuspend(dev) and return its result
void pm_runtime_enable(struct device *dev); void pm_runtime_enable(struct device *dev);
- enable the run-time PM helper functions to run the device bus type's - decrement the device's 'power.disable_depth' field; if that field is equal
run-time PM callbacks described in Section 2 to zero, the runtime PM helper functions can execute subsystem-level
callbacks described in Section 2 for the device
int pm_runtime_disable(struct device *dev); int pm_runtime_disable(struct device *dev);
- prevent the run-time PM helper functions from running subsystem-level - increment the device's 'power.disable_depth' field (if the value of that
run-time PM callbacks for the device, make sure that all of the pending field was previously zero, this prevents subsystem-level runtime PM
run-time PM operations on the device are either completed or canceled; callbacks from being run for the device), make sure that all of the pending
runtime PM operations on the device are either completed or canceled;
returns 1 if there was a resume request pending and it was necessary to returns 1 if there was a resume request pending and it was necessary to
execute the subsystem-level resume callback for the device to satisfy that execute the subsystem-level resume callback for the device to satisfy that
request, otherwise 0 is returned request, otherwise 0 is returned
int pm_runtime_barrier(struct device *dev);
- check if there's a resume request pending for the device and resume it
(synchronously) in that case, cancel any other pending runtime PM requests
regarding it and wait for all runtime PM operations on it in progress to
complete; returns 1 if there was a resume request pending and it was
necessary to execute the subsystem-level resume callback for the device to
satisfy that request, otherwise 0 is returned
void pm_suspend_ignore_children(struct device *dev, bool enable); void pm_suspend_ignore_children(struct device *dev, bool enable);
- set/unset the power.ignore_children flag of the device - set/unset the power.ignore_children flag of the device
int pm_runtime_set_active(struct device *dev); int pm_runtime_set_active(struct device *dev);
- clear the device's 'power.runtime_error' flag, set the device's run-time - clear the device's 'power.runtime_error' flag, set the device's runtime
PM status to 'active' and update its parent's counter of 'active' PM status to 'active' and update its parent's counter of 'active'
children as appropriate (it is only valid to use this function if children as appropriate (it is only valid to use this function if
'power.runtime_error' is set or 'power.disable_depth' is greater than 'power.runtime_error' is set or 'power.disable_depth' is greater than
@ -390,7 +402,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
which is not active and the 'power.ignore_children' flag of which is unset which is not active and the 'power.ignore_children' flag of which is unset
void pm_runtime_set_suspended(struct device *dev); void pm_runtime_set_suspended(struct device *dev);
- clear the device's 'power.runtime_error' flag, set the device's run-time - clear the device's 'power.runtime_error' flag, set the device's runtime
PM status to 'suspended' and update its parent's counter of 'active' PM status to 'suspended' and update its parent's counter of 'active'
children as appropriate (it is only valid to use this function if children as appropriate (it is only valid to use this function if
'power.runtime_error' is set or 'power.disable_depth' is greater than 'power.runtime_error' is set or 'power.disable_depth' is greater than
@ -400,6 +412,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
- return true if the device's runtime PM status is 'suspended' and its - return true if the device's runtime PM status is 'suspended' and its
'power.disable_depth' field is equal to zero, or false otherwise 'power.disable_depth' field is equal to zero, or false otherwise
bool pm_runtime_status_suspended(struct device *dev);
- return true if the device's runtime PM status is 'suspended'
void pm_runtime_allow(struct device *dev); void pm_runtime_allow(struct device *dev);
- set the power.runtime_auto flag for the device and decrease its usage - set the power.runtime_auto flag for the device and decrease its usage
counter (used by the /sys/devices/.../power/control interface to counter (used by the /sys/devices/.../power/control interface to
@ -411,7 +426,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
effectively prevent the device from being power managed at run time) effectively prevent the device from being power managed at run time)
void pm_runtime_no_callbacks(struct device *dev); void pm_runtime_no_callbacks(struct device *dev);
- set the power.no_callbacks flag for the device and remove the run-time - set the power.no_callbacks flag for the device and remove the runtime
PM attributes from /sys/devices/.../power (or prevent them from being PM attributes from /sys/devices/.../power (or prevent them from being
added when the device is registered) added when the device is registered)
@ -431,7 +446,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
void pm_runtime_set_autosuspend_delay(struct device *dev, int delay); void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
- set the power.autosuspend_delay value to 'delay' (expressed in - set the power.autosuspend_delay value to 'delay' (expressed in
milliseconds); if 'delay' is negative then run-time suspends are milliseconds); if 'delay' is negative then runtime suspends are
prevented prevented
unsigned long pm_runtime_autosuspend_expiration(struct device *dev); unsigned long pm_runtime_autosuspend_expiration(struct device *dev);
@ -470,35 +485,35 @@ pm_runtime_resume()
pm_runtime_get_sync() pm_runtime_get_sync()
pm_runtime_put_sync_suspend() pm_runtime_put_sync_suspend()
5. Run-time PM Initialization, Device Probing and Removal 5. Runtime PM Initialization, Device Probing and Removal
Initially, the run-time PM is disabled for all devices, which means that the Initially, the runtime PM is disabled for all devices, which means that the
majority of the run-time PM helper funtions described in Section 4 will return majority of the runtime PM helper funtions described in Section 4 will return
-EAGAIN until pm_runtime_enable() is called for the device. -EAGAIN until pm_runtime_enable() is called for the device.
In addition to that, the initial run-time PM status of all devices is In addition to that, the initial runtime PM status of all devices is
'suspended', but it need not reflect the actual physical state of the device. 'suspended', but it need not reflect the actual physical state of the device.
Thus, if the device is initially active (i.e. it is able to process I/O), its Thus, if the device is initially active (i.e. it is able to process I/O), its
run-time PM status must be changed to 'active', with the help of runtime PM status must be changed to 'active', with the help of
pm_runtime_set_active(), before pm_runtime_enable() is called for the device. pm_runtime_set_active(), before pm_runtime_enable() is called for the device.
However, if the device has a parent and the parent's run-time PM is enabled, However, if the device has a parent and the parent's runtime PM is enabled,
calling pm_runtime_set_active() for the device will affect the parent, unless calling pm_runtime_set_active() for the device will affect the parent, unless
the parent's 'power.ignore_children' flag is set. Namely, in that case the the parent's 'power.ignore_children' flag is set. Namely, in that case the
parent won't be able to suspend at run time, using the PM core's helper parent won't be able to suspend at run time, using the PM core's helper
functions, as long as the child's status is 'active', even if the child's functions, as long as the child's status is 'active', even if the child's
run-time PM is still disabled (i.e. pm_runtime_enable() hasn't been called for runtime PM is still disabled (i.e. pm_runtime_enable() hasn't been called for
the child yet or pm_runtime_disable() has been called for it). For this reason, the child yet or pm_runtime_disable() has been called for it). For this reason,
once pm_runtime_set_active() has been called for the device, pm_runtime_enable() once pm_runtime_set_active() has been called for the device, pm_runtime_enable()
should be called for it too as soon as reasonably possible or its run-time PM should be called for it too as soon as reasonably possible or its runtime PM
status should be changed back to 'suspended' with the help of status should be changed back to 'suspended' with the help of
pm_runtime_set_suspended(). pm_runtime_set_suspended().
If the default initial run-time PM status of the device (i.e. 'suspended') If the default initial runtime PM status of the device (i.e. 'suspended')
reflects the actual state of the device, its bus type's or its driver's reflects the actual state of the device, its bus type's or its driver's
->probe() callback will likely need to wake it up using one of the PM core's ->probe() callback will likely need to wake it up using one of the PM core's
helper functions described in Section 4. In that case, pm_runtime_resume() helper functions described in Section 4. In that case, pm_runtime_resume()
should be used. Of course, for this purpose the device's run-time PM has to be should be used. Of course, for this purpose the device's runtime PM has to be
enabled earlier by calling pm_runtime_enable(). enabled earlier by calling pm_runtime_enable().
If the device bus type's or driver's ->probe() callback runs If the device bus type's or driver's ->probe() callback runs
@ -529,33 +544,33 @@ The user space can effectively disallow the driver of the device to power manage
it at run time by changing the value of its /sys/devices/.../power/control it at run time by changing the value of its /sys/devices/.../power/control
attribute to "on", which causes pm_runtime_forbid() to be called. In principle, attribute to "on", which causes pm_runtime_forbid() to be called. In principle,
this mechanism may also be used by the driver to effectively turn off the this mechanism may also be used by the driver to effectively turn off the
run-time power management of the device until the user space turns it on. runtime power management of the device until the user space turns it on.
Namely, during the initialization the driver can make sure that the run-time PM Namely, during the initialization the driver can make sure that the runtime PM
status of the device is 'active' and call pm_runtime_forbid(). It should be status of the device is 'active' and call pm_runtime_forbid(). It should be
noted, however, that if the user space has already intentionally changed the noted, however, that if the user space has already intentionally changed the
value of /sys/devices/.../power/control to "auto" to allow the driver to power value of /sys/devices/.../power/control to "auto" to allow the driver to power
manage the device at run time, the driver may confuse it by using manage the device at run time, the driver may confuse it by using
pm_runtime_forbid() this way. pm_runtime_forbid() this way.
6. Run-time PM and System Sleep 6. Runtime PM and System Sleep
Run-time PM and system sleep (i.e., system suspend and hibernation, also known Runtime PM and system sleep (i.e., system suspend and hibernation, also known
as suspend-to-RAM and suspend-to-disk) interact with each other in a couple of as suspend-to-RAM and suspend-to-disk) interact with each other in a couple of
ways. If a device is active when a system sleep starts, everything is ways. If a device is active when a system sleep starts, everything is
straightforward. But what should happen if the device is already suspended? straightforward. But what should happen if the device is already suspended?
The device may have different wake-up settings for run-time PM and system sleep. The device may have different wake-up settings for runtime PM and system sleep.
For example, remote wake-up may be enabled for run-time suspend but disallowed For example, remote wake-up may be enabled for runtime suspend but disallowed
for system sleep (device_may_wakeup(dev) returns 'false'). When this happens, for system sleep (device_may_wakeup(dev) returns 'false'). When this happens,
the subsystem-level system suspend callback is responsible for changing the the subsystem-level system suspend callback is responsible for changing the
device's wake-up setting (it may leave that to the device driver's system device's wake-up setting (it may leave that to the device driver's system
suspend routine). It may be necessary to resume the device and suspend it again suspend routine). It may be necessary to resume the device and suspend it again
in order to do so. The same is true if the driver uses different power levels in order to do so. The same is true if the driver uses different power levels
or other settings for run-time suspend and system sleep. or other settings for runtime suspend and system sleep.
During system resume, devices generally should be brought back to full power, During system resume, the simplest approach is to bring all devices back to full
even if they were suspended before the system sleep began. There are several power, even if they had been suspended before the system suspend began. There
reasons for this, including: are several reasons for this, including:
* The device might need to switch power levels, wake-up settings, etc. * The device might need to switch power levels, wake-up settings, etc.
@ -570,18 +585,50 @@ reasons for this, including:
* The device might need to be reset. * The device might need to be reset.
* Even though the device was suspended, if its usage counter was > 0 then most * Even though the device was suspended, if its usage counter was > 0 then most
likely it would need a run-time resume in the near future anyway. likely it would need a runtime resume in the near future anyway.
* Always going back to full power is simplest. If the device had been suspended before the system suspend began and it's
brought back to full power during resume, then its runtime PM status will have
If the device was suspended before the sleep began, then its run-time PM status to be updated to reflect the actual post-system sleep status. The way to do
will have to be updated to reflect the actual post-system sleep status. The way this is:
to do this is:
pm_runtime_disable(dev); pm_runtime_disable(dev);
pm_runtime_set_active(dev); pm_runtime_set_active(dev);
pm_runtime_enable(dev); pm_runtime_enable(dev);
The PM core always increments the runtime usage counter before calling the
->suspend() callback and decrements it after calling the ->resume() callback.
Hence disabling runtime PM temporarily like this will not cause any runtime
suspend attempts to be permanently lost. If the usage count goes to zero
following the return of the ->resume() callback, the ->runtime_idle() callback
will be invoked as usual.
On some systems, however, system sleep is not entered through a global firmware
or hardware operation. Instead, all hardware components are put into low-power
states directly by the kernel in a coordinated way. Then, the system sleep
state effectively follows from the states the hardware components end up in
and the system is woken up from that state by a hardware interrupt or a similar
mechanism entirely under the kernel's control. As a result, the kernel never
gives control away and the states of all devices during resume are precisely
known to it. If that is the case and none of the situations listed above takes
place (in particular, if the system is not waking up from hibernation), it may
be more efficient to leave the devices that had been suspended before the system
suspend began in the suspended state.
The PM core does its best to reduce the probability of race conditions between
the runtime PM and system suspend/resume (and hibernation) callbacks by carrying
out the following operations:
* During system suspend it calls pm_runtime_get_noresume() and
pm_runtime_barrier() for every device right before executing the
subsystem-level .suspend() callback for it. In addition to that it calls
pm_runtime_disable() for every device right after executing the
subsystem-level .suspend() callback for it.
* During system resume it calls pm_runtime_enable() and pm_runtime_put_sync()
for every device right before and right after executing the subsystem-level
.resume() callback for it, respectively.
7. Generic subsystem callbacks 7. Generic subsystem callbacks
Subsystems may wish to conserve code space by using the set of generic power Subsystems may wish to conserve code space by using the set of generic power
@ -666,8 +713,8 @@ the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its
dev_pm_ops structure pointer. dev_pm_ops structure pointer.
Device drivers that wish to use the same function as a system suspend, freeze, Device drivers that wish to use the same function as a system suspend, freeze,
poweroff and run-time suspend callback, and similarly for system resume, thaw, poweroff and runtime suspend callback, and similarly for system resume, thaw,
restore, and run-time resume, can achieve this with the help of the restore, and runtime resume, can achieve this with the help of the
UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its
last argument to NULL). last argument to NULL).
@ -677,7 +724,7 @@ Some "devices" are only logical sub-devices of their parent and cannot be
power-managed on their own. (The prototype example is a USB interface. Entire power-managed on their own. (The prototype example is a USB interface. Entire
USB devices can go into low-power mode or send wake-up requests, but neither is USB devices can go into low-power mode or send wake-up requests, but neither is
possible for individual interfaces.) The drivers for these devices have no possible for individual interfaces.) The drivers for these devices have no
need of run-time PM callbacks; if the callbacks did exist, ->runtime_suspend() need of runtime PM callbacks; if the callbacks did exist, ->runtime_suspend()
and ->runtime_resume() would always return 0 without doing anything else and and ->runtime_resume() would always return 0 without doing anything else and
->runtime_idle() would always call pm_runtime_suspend(). ->runtime_idle() would always call pm_runtime_suspend().
@ -685,7 +732,7 @@ Subsystems can tell the PM core about these devices by calling
pm_runtime_no_callbacks(). This should be done after the device structure is pm_runtime_no_callbacks(). This should be done after the device structure is
initialized and before it is registered (although after device registration is initialized and before it is registered (although after device registration is
also okay). The routine will set the device's power.no_callbacks flag and also okay). The routine will set the device's power.no_callbacks flag and
prevent the non-debugging run-time PM sysfs attributes from being created. prevent the non-debugging runtime PM sysfs attributes from being created.
When power.no_callbacks is set, the PM core will not invoke the When power.no_callbacks is set, the PM core will not invoke the
->runtime_idle(), ->runtime_suspend(), or ->runtime_resume() callbacks. ->runtime_idle(), ->runtime_suspend(), or ->runtime_resume() callbacks.
@ -693,7 +740,7 @@ Instead it will assume that suspends and resumes always succeed and that idle
devices should be suspended. devices should be suspended.
As a consequence, the PM core will never directly inform the device's subsystem As a consequence, the PM core will never directly inform the device's subsystem
or driver about run-time power changes. Instead, the driver for the device's or driver about runtime power changes. Instead, the driver for the device's
parent must take responsibility for telling the device's driver when the parent must take responsibility for telling the device's driver when the
parent's power state changes. parent's power state changes.
@ -704,13 +751,13 @@ A device should be put in a low-power state only when there's some reason to
think it will remain in that state for a substantial time. A common heuristic think it will remain in that state for a substantial time. A common heuristic
says that a device which hasn't been used for a while is liable to remain says that a device which hasn't been used for a while is liable to remain
unused; following this advice, drivers should not allow devices to be suspended unused; following this advice, drivers should not allow devices to be suspended
at run-time until they have been inactive for some minimum period. Even when at runtime until they have been inactive for some minimum period. Even when
the heuristic ends up being non-optimal, it will still prevent devices from the heuristic ends up being non-optimal, it will still prevent devices from
"bouncing" too rapidly between low-power and full-power states. "bouncing" too rapidly between low-power and full-power states.
The term "autosuspend" is an historical remnant. It doesn't mean that the The term "autosuspend" is an historical remnant. It doesn't mean that the
device is automatically suspended (the subsystem or driver still has to call device is automatically suspended (the subsystem or driver still has to call
the appropriate PM routines); rather it means that run-time suspends will the appropriate PM routines); rather it means that runtime suspends will
automatically be delayed until the desired period of inactivity has elapsed. automatically be delayed until the desired period of inactivity has elapsed.
Inactivity is determined based on the power.last_busy field. Drivers should Inactivity is determined based on the power.last_busy field. Drivers should

2
arch/arm/mach-omap2/gpio.c
View File

@ -87,6 +87,8 @@ static int omap2_gpio_dev_init(struct omap_hwmod *oh, void *unused)
return PTR_ERR(od); return PTR_ERR(od);
} }
omap_device_disable_idle_on_suspend(od);
gpio_bank_count++; gpio_bank_count++;
return 0; return 0;
} }

1
arch/arm/mach-omap2/serial.c
View File

@ -805,6 +805,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
WARN(IS_ERR(od), "Could not build omap_device for %s: %s.\n", WARN(IS_ERR(od), "Could not build omap_device for %s: %s.\n",
name, oh->name); name, oh->name);
omap_device_disable_idle_on_suspend(od);
oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt); oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
uart->irq = oh->mpu_irqs[0].irq; uart->irq = oh->mpu_irqs[0].irq;

9
arch/arm/plat-omap/include/plat/omap_device.h
View File

@ -44,6 +44,10 @@ extern struct device omap_device_parent;
#define OMAP_DEVICE_STATE_IDLE 2 #define OMAP_DEVICE_STATE_IDLE 2
#define OMAP_DEVICE_STATE_SHUTDOWN 3 #define OMAP_DEVICE_STATE_SHUTDOWN 3
/* omap_device.flags values */
#define OMAP_DEVICE_SUSPENDED BIT(0)
#define OMAP_DEVICE_NO_IDLE_ON_SUSPEND BIT(1)
/** /**
* struct omap_device - omap_device wrapper for platform_devices * struct omap_device - omap_device wrapper for platform_devices
* @pdev: platform_device * @pdev: platform_device
@ -73,6 +77,7 @@ struct omap_device {
s8 pm_lat_level; s8 pm_lat_level;
u8 hwmods_cnt; u8 hwmods_cnt;
u8 _state; u8 _state;
u8 flags;
}; };
/* Device driver interface (call via platform_data fn ptrs) */ /* Device driver interface (call via platform_data fn ptrs) */
@ -117,6 +122,10 @@ int omap_device_enable_hwmods(struct omap_device *od);
int omap_device_disable_clocks(struct omap_device *od); int omap_device_disable_clocks(struct omap_device *od);
int omap_device_enable_clocks(struct omap_device *od); int omap_device_enable_clocks(struct omap_device *od);
static inline void omap_device_disable_idle_on_suspend(struct omap_device *od)
{
od->flags |= OMAP_DEVICE_NO_IDLE_ON_SUSPEND;
}
/* /*
* Entries should be kept in latency order ascending * Entries should be kept in latency order ascending

49
arch/arm/plat-omap/omap_device.c
View File

@ -537,6 +537,7 @@ int omap_early_device_register(struct omap_device *od)
return 0; return 0;
} }
#ifdef CONFIG_PM_RUNTIME
static int _od_runtime_suspend(struct device *dev) static int _od_runtime_suspend(struct device *dev)
{ {
struct platform_device *pdev = to_platform_device(dev); struct platform_device *pdev = to_platform_device(dev);
@ -563,13 +564,55 @@ static int _od_runtime_resume(struct device *dev)
return pm_generic_runtime_resume(dev); return pm_generic_runtime_resume(dev);
} }
#endif
#ifdef CONFIG_SUSPEND
static int _od_suspend_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct omap_device *od = to_omap_device(pdev);
int ret;
if (od->flags & OMAP_DEVICE_NO_IDLE_ON_SUSPEND)
return pm_generic_suspend_noirq(dev);
ret = pm_generic_suspend_noirq(dev);
if (!ret && !pm_runtime_status_suspended(dev)) {
if (pm_generic_runtime_suspend(dev) == 0) {
omap_device_idle(pdev);
od->flags |= OMAP_DEVICE_SUSPENDED;
}
}
return ret;
}
static int _od_resume_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct omap_device *od = to_omap_device(pdev);
if (od->flags & OMAP_DEVICE_NO_IDLE_ON_SUSPEND)
return pm_generic_resume_noirq(dev);
if ((od->flags & OMAP_DEVICE_SUSPENDED) &&
!pm_runtime_status_suspended(dev)) {
od->flags &= ~OMAP_DEVICE_SUSPENDED;
omap_device_enable(pdev);
pm_generic_runtime_resume(dev);
}
return pm_generic_resume_noirq(dev);
}
#endif
static struct dev_pm_domain omap_device_pm_domain = { static struct dev_pm_domain omap_device_pm_domain = {
.ops = { .ops = {
.runtime_suspend = _od_runtime_suspend, SET_RUNTIME_PM_OPS(_od_runtime_suspend, _od_runtime_resume,
.runtime_idle = _od_runtime_idle, _od_runtime_idle)
.runtime_resume = _od_runtime_resume,
USE_PLATFORM_PM_SLEEP_OPS USE_PLATFORM_PM_SLEEP_OPS
SET_SYSTEM_SLEEP_PM_OPS(_od_suspend_noirq, _od_resume_noirq)
} }
}; };

35
drivers/base/power/main.c
View File

@ -505,6 +505,7 @@ static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
static int device_resume(struct device *dev, pm_message_t state, bool async) static int device_resume(struct device *dev, pm_message_t state, bool async)
{ {
int error = 0; int error = 0;
bool put = false;
TRACE_DEVICE(dev); TRACE_DEVICE(dev);
TRACE_RESUME(0); TRACE_RESUME(0);
@ -521,6 +522,9 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
if (!dev->power.is_suspended) if (!dev->power.is_suspended)
goto Unlock; goto Unlock;
pm_runtime_enable(dev);
put = true;
if (dev->pm_domain) { if (dev->pm_domain) {
pm_dev_dbg(dev, state, "power domain "); pm_dev_dbg(dev, state, "power domain ");
error = pm_op(dev, &dev->pm_domain->ops, state); error = pm_op(dev, &dev->pm_domain->ops, state);
@ -563,6 +567,10 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
complete_all(&dev->power.completion); complete_all(&dev->power.completion);
TRACE_RESUME(error); TRACE_RESUME(error);
if (put)
pm_runtime_put_sync(dev);
return error; return error;
} }
@ -843,16 +851,22 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
int error = 0; int error = 0;
dpm_wait_for_children(dev, async); dpm_wait_for_children(dev, async);
device_lock(dev);
if (async_error) if (async_error)
goto Unlock; return 0;
pm_runtime_get_noresume(dev);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
if (pm_wakeup_pending()) { if (pm_wakeup_pending()) {
pm_runtime_put_sync(dev);
async_error = -EBUSY; async_error = -EBUSY;
goto Unlock; return 0;
} }
device_lock(dev);
if (dev->pm_domain) { if (dev->pm_domain) {
pm_dev_dbg(dev, state, "power domain "); pm_dev_dbg(dev, state, "power domain ");
error = pm_op(dev, &dev->pm_domain->ops, state); error = pm_op(dev, &dev->pm_domain->ops, state);
@ -890,12 +904,15 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
End: End:
dev->power.is_suspended = !error; dev->power.is_suspended = !error;
Unlock:
device_unlock(dev); device_unlock(dev);
complete_all(&dev->power.completion); complete_all(&dev->power.completion);
if (error) if (error) {
pm_runtime_put_sync(dev);
async_error = error; async_error = error;
} else if (dev->power.is_suspended) {
__pm_runtime_disable(dev, false);
}
return error; return error;
} }
@ -1035,13 +1052,7 @@ int dpm_prepare(pm_message_t state)
get_device(dev); get_device(dev);
mutex_unlock(&dpm_list_mtx); mutex_unlock(&dpm_list_mtx);
pm_runtime_get_noresume(dev); error = device_prepare(dev, state);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
pm_runtime_put_sync(dev);
error = pm_wakeup_pending() ?
-EBUSY : device_prepare(dev, state);
mutex_lock(&dpm_list_mtx); mutex_lock(&dpm_list_mtx);
if (error) { if (error) {

77
drivers/base/power/runtime.c
View File

@ -1,5 +1,5 @@
/* /*
* drivers/base/power/runtime.c - Helper functions for device run-time PM * drivers/base/power/runtime.c - Helper functions for device runtime PM
* *
* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
* Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu> * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
@ -135,8 +135,9 @@ static int rpm_check_suspend_allowed(struct device *dev)
if (dev->power.runtime_error) if (dev->power.runtime_error)
retval = -EINVAL; retval = -EINVAL;
else if (atomic_read(&dev->power.usage_count) > 0 else if (dev->power.disable_depth > 0)
|| dev->power.disable_depth > 0) retval = -EACCES;
else if (atomic_read(&dev->power.usage_count) > 0)
retval = -EAGAIN; retval = -EAGAIN;
else if (!pm_children_suspended(dev)) else if (!pm_children_suspended(dev))
retval = -EBUSY; retval = -EBUSY;
@ -158,7 +159,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
* @dev: Device to notify the bus type about. * @dev: Device to notify the bus type about.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
* Check if the device's run-time PM status allows it to be suspended. If * Check if the device's runtime PM status allows it to be suspended. If
* another idle notification has been started earlier, return immediately. If * another idle notification has been started earlier, return immediately. If
* the RPM_ASYNC flag is set then queue an idle-notification request; otherwise * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
* run the ->runtime_idle() callback directly. * run the ->runtime_idle() callback directly.
@ -262,15 +263,15 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
spin_lock_irq(&dev->power.lock); spin_lock_irq(&dev->power.lock);
} }
dev->power.runtime_error = retval; dev->power.runtime_error = retval;
return retval; return retval != -EACCES ? retval : -EIO;
} }
/** /**
* rpm_suspend - Carry out run-time suspend of given device. * rpm_suspend - Carry out runtime suspend of given device.
* @dev: Device to suspend. * @dev: Device to suspend.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
* Check if the device's run-time PM status allows it to be suspended. If * Check if the device's runtime PM status allows it to be suspended. If
* another suspend has been started earlier, either return immediately or wait * another suspend has been started earlier, either return immediately or wait
* for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags. Cancel a * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags. Cancel a
* pending idle notification. If the RPM_ASYNC flag is set then queue a * pending idle notification. If the RPM_ASYNC flag is set then queue a
@ -388,7 +389,7 @@ static int rpm_suspend(struct device *dev, int rpmflags)
retval = rpm_callback(callback, dev); retval = rpm_callback(callback, dev);
if (retval) { if (retval) {
__update_runtime_status(dev, RPM_ACTIVE); __update_runtime_status(dev, RPM_ACTIVE);
dev->power.deferred_resume = 0; dev->power.deferred_resume = false;
if (retval == -EAGAIN || retval == -EBUSY) if (retval == -EAGAIN || retval == -EBUSY)
dev->power.runtime_error = 0; dev->power.runtime_error = 0;
else else
@ -429,11 +430,11 @@ static int rpm_suspend(struct device *dev, int rpmflags)
} }
/** /**
* rpm_resume - Carry out run-time resume of given device. * rpm_resume - Carry out runtime resume of given device.
* @dev: Device to resume. * @dev: Device to resume.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
* Check if the device's run-time PM status allows it to be resumed. Cancel * Check if the device's runtime PM status allows it to be resumed. Cancel
* any scheduled or pending requests. If another resume has been started * any scheduled or pending requests. If another resume has been started
* earlier, either return immediately or wait for it to finish, depending on the * earlier, either return immediately or wait for it to finish, depending on the
* RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
@ -458,7 +459,7 @@ static int rpm_resume(struct device *dev, int rpmflags)
if (dev->power.runtime_error) if (dev->power.runtime_error)
retval = -EINVAL; retval = -EINVAL;
else if (dev->power.disable_depth > 0) else if (dev->power.disable_depth > 0)
retval = -EAGAIN; retval = -EACCES;
if (retval) if (retval)
goto out; goto out;
@ -550,7 +551,7 @@ static int rpm_resume(struct device *dev, int rpmflags)
spin_lock(&parent->power.lock); spin_lock(&parent->power.lock);
/* /*
* We can resume if the parent's run-time PM is disabled or it * We can resume if the parent's runtime PM is disabled or it
* is set to ignore children. * is set to ignore children.
*/ */
if (!parent->power.disable_depth if (!parent->power.disable_depth
@ -614,11 +615,11 @@ static int rpm_resume(struct device *dev, int rpmflags)
} }
/** /**
* pm_runtime_work - Universal run-time PM work function. * pm_runtime_work - Universal runtime PM work function.
* @work: Work structure used for scheduling the execution of this function. * @work: Work structure used for scheduling the execution of this function.
* *
* Use @work to get the device object the work is to be done for, determine what * Use @work to get the device object the work is to be done for, determine what
* is to be done and execute the appropriate run-time PM function. * is to be done and execute the appropriate runtime PM function.
*/ */
static void pm_runtime_work(struct work_struct *work) static void pm_runtime_work(struct work_struct *work)
{ {
@ -717,7 +718,7 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)
EXPORT_SYMBOL_GPL(pm_schedule_suspend); EXPORT_SYMBOL_GPL(pm_schedule_suspend);
/** /**
* __pm_runtime_idle - Entry point for run-time idle operations. * __pm_runtime_idle - Entry point for runtime idle operations.
* @dev: Device to send idle notification for. * @dev: Device to send idle notification for.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
@ -746,7 +747,7 @@ int __pm_runtime_idle(struct device *dev, int rpmflags)
EXPORT_SYMBOL_GPL(__pm_runtime_idle); EXPORT_SYMBOL_GPL(__pm_runtime_idle);
/** /**
* __pm_runtime_suspend - Entry point for run-time put/suspend operations. * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
* @dev: Device to suspend. * @dev: Device to suspend.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
@ -775,7 +776,7 @@ int __pm_runtime_suspend(struct device *dev, int rpmflags)
EXPORT_SYMBOL_GPL(__pm_runtime_suspend); EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
/** /**
* __pm_runtime_resume - Entry point for run-time resume operations. * __pm_runtime_resume - Entry point for runtime resume operations.
* @dev: Device to resume. * @dev: Device to resume.
* @rpmflags: Flag bits. * @rpmflags: Flag bits.
* *
@ -801,11 +802,11 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
EXPORT_SYMBOL_GPL(__pm_runtime_resume); EXPORT_SYMBOL_GPL(__pm_runtime_resume);
/** /**
* __pm_runtime_set_status - Set run-time PM status of a device. * __pm_runtime_set_status - Set runtime PM status of a device.
* @dev: Device to handle. * @dev: Device to handle.
* @status: New run-time PM status of the device. * @status: New runtime PM status of the device.
* *
* If run-time PM of the device is disabled or its power.runtime_error field is * If runtime PM of the device is disabled or its power.runtime_error field is
* different from zero, the status may be changed either to RPM_ACTIVE, or to * different from zero, the status may be changed either to RPM_ACTIVE, or to
* RPM_SUSPENDED, as long as that reflects the actual state of the device. * RPM_SUSPENDED, as long as that reflects the actual state of the device.
* However, if the device has a parent and the parent is not active, and the * However, if the device has a parent and the parent is not active, and the
@ -851,7 +852,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
/* /*
* It is invalid to put an active child under a parent that is * It is invalid to put an active child under a parent that is
* not active, has run-time PM enabled and the * not active, has runtime PM enabled and the
* 'power.ignore_children' flag unset. * 'power.ignore_children' flag unset.
*/ */
if (!parent->power.disable_depth if (!parent->power.disable_depth
@ -885,7 +886,7 @@ EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
* @dev: Device to handle. * @dev: Device to handle.
* *
* Flush all pending requests for the device from pm_wq and wait for all * Flush all pending requests for the device from pm_wq and wait for all
* run-time PM operations involving the device in progress to complete. * runtime PM operations involving the device in progress to complete.
* *
* Should be called under dev->power.lock with interrupts disabled. * Should be called under dev->power.lock with interrupts disabled.
*/ */
@ -933,7 +934,7 @@ static void __pm_runtime_barrier(struct device *dev)
* Prevent the device from being suspended by incrementing its usage counter and * Prevent the device from being suspended by incrementing its usage counter and
* if there's a pending resume request for the device, wake the device up. * if there's a pending resume request for the device, wake the device up.
* Next, make sure that all pending requests for the device have been flushed * Next, make sure that all pending requests for the device have been flushed
* from pm_wq and wait for all run-time PM operations involving the device in * from pm_wq and wait for all runtime PM operations involving the device in
* progress to complete. * progress to complete.
* *
* Return value: * Return value:
@ -963,18 +964,18 @@ int pm_runtime_barrier(struct device *dev)
EXPORT_SYMBOL_GPL(pm_runtime_barrier); EXPORT_SYMBOL_GPL(pm_runtime_barrier);
/** /**
* __pm_runtime_disable - Disable run-time PM of a device. * __pm_runtime_disable - Disable runtime PM of a device.
* @dev: Device to handle. * @dev: Device to handle.
* @check_resume: If set, check if there's a resume request for the device. * @check_resume: If set, check if there's a resume request for the device.
* *
* Increment power.disable_depth for the device and if was zero previously, * Increment power.disable_depth for the device and if was zero previously,
* cancel all pending run-time PM requests for the device and wait for all * cancel all pending runtime PM requests for the device and wait for all
* operations in progress to complete. The device can be either active or * operations in progress to complete. The device can be either active or
* suspended after its run-time PM has been disabled. * suspended after its runtime PM has been disabled.
* *
* If @check_resume is set and there's a resume request pending when * If @check_resume is set and there's a resume request pending when
* __pm_runtime_disable() is called and power.disable_depth is zero, the * __pm_runtime_disable() is called and power.disable_depth is zero, the
* function will wake up the device before disabling its run-time PM. * function will wake up the device before disabling its runtime PM.
*/ */
void __pm_runtime_disable(struct device *dev, bool check_resume) void __pm_runtime_disable(struct device *dev, bool check_resume)
{ {
@ -987,7 +988,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume)
/* /*
* Wake up the device if there's a resume request pending, because that * Wake up the device if there's a resume request pending, because that
* means there probably is some I/O to process and disabling run-time PM * means there probably is some I/O to process and disabling runtime PM
* shouldn't prevent the device from processing the I/O. * shouldn't prevent the device from processing the I/O.
*/ */
if (check_resume && dev->power.request_pending if (check_resume && dev->power.request_pending
@ -1012,7 +1013,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume)
EXPORT_SYMBOL_GPL(__pm_runtime_disable); EXPORT_SYMBOL_GPL(__pm_runtime_disable);
/** /**
* pm_runtime_enable - Enable run-time PM of a device. * pm_runtime_enable - Enable runtime PM of a device.
* @dev: Device to handle. * @dev: Device to handle.
*/ */
void pm_runtime_enable(struct device *dev) void pm_runtime_enable(struct device *dev)
@ -1031,7 +1032,7 @@ void pm_runtime_enable(struct device *dev)
EXPORT_SYMBOL_GPL(pm_runtime_enable); EXPORT_SYMBOL_GPL(pm_runtime_enable);
/** /**
* pm_runtime_forbid - Block run-time PM of a device. * pm_runtime_forbid - Block runtime PM of a device.
* @dev: Device to handle. * @dev: Device to handle.
* *
* Increase the device's usage count and clear its power.runtime_auto flag, * Increase the device's usage count and clear its power.runtime_auto flag,
@ -1054,7 +1055,7 @@ void pm_runtime_forbid(struct device *dev)
EXPORT_SYMBOL_GPL(pm_runtime_forbid); EXPORT_SYMBOL_GPL(pm_runtime_forbid);
/** /**
* pm_runtime_allow - Unblock run-time PM of a device. * pm_runtime_allow - Unblock runtime PM of a device.
* @dev: Device to handle. * @dev: Device to handle.
* *
* Decrease the device's usage count and set its power.runtime_auto flag. * Decrease the device's usage count and set its power.runtime_auto flag.
@ -1075,12 +1076,12 @@ void pm_runtime_allow(struct device *dev)
EXPORT_SYMBOL_GPL(pm_runtime_allow); EXPORT_SYMBOL_GPL(pm_runtime_allow);
/** /**
* pm_runtime_no_callbacks - Ignore run-time PM callbacks for a device. * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
* @dev: Device to handle. * @dev: Device to handle.
* *
* Set the power.no_callbacks flag, which tells the PM core that this * Set the power.no_callbacks flag, which tells the PM core that this
* device is power-managed through its parent and has no run-time PM * device is power-managed through its parent and has no runtime PM
* callbacks of its own. The run-time sysfs attributes will be removed. * callbacks of its own. The runtime sysfs attributes will be removed.
*/ */
void pm_runtime_no_callbacks(struct device *dev) void pm_runtime_no_callbacks(struct device *dev)
{ {
@ -1156,8 +1157,8 @@ static void update_autosuspend(struct device *dev, int old_delay, int old_use)
* @delay: Value of the new delay in milliseconds. * @delay: Value of the new delay in milliseconds.
* *
* Set the device's power.autosuspend_delay value. If it changes to negative * Set the device's power.autosuspend_delay value. If it changes to negative
* and the power.use_autosuspend flag is set, prevent run-time suspends. If it * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
* changes the other way, allow run-time suspends. * changes the other way, allow runtime suspends.
*/ */
void pm_runtime_set_autosuspend_delay(struct device *dev, int delay) void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
{ {
@ -1177,7 +1178,7 @@ EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
* @dev: Device to handle. * @dev: Device to handle.
* @use: New value for use_autosuspend. * @use: New value for use_autosuspend.
* *
* Set the device's power.use_autosuspend flag, and allow or prevent run-time * Set the device's power.use_autosuspend flag, and allow or prevent runtime
* suspends as needed. * suspends as needed.
*/ */
void __pm_runtime_use_autosuspend(struct device *dev, bool use) void __pm_runtime_use_autosuspend(struct device *dev, bool use)
@ -1194,7 +1195,7 @@ void __pm_runtime_use_autosuspend(struct device *dev, bool use)
EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend); EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
/** /**
* pm_runtime_init - Initialize run-time PM fields in given device object. * pm_runtime_init - Initialize runtime PM fields in given device object.
* @dev: Device object to initialize. * @dev: Device object to initialize.
*/ */
void pm_runtime_init(struct device *dev) void pm_runtime_init(struct device *dev)

6
drivers/base/power/sysfs.c
View File

@ -116,12 +116,14 @@ static ssize_t control_store(struct device * dev, struct device_attribute *attr,
cp = memchr(buf, '\n', n); cp = memchr(buf, '\n', n);
if (cp) if (cp)
len = cp - buf; len = cp - buf;
device_lock(dev);
if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0) if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
pm_runtime_allow(dev); pm_runtime_allow(dev);
else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0) else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
pm_runtime_forbid(dev); pm_runtime_forbid(dev);
else else
return -EINVAL; n = -EINVAL;
device_unlock(dev);
return n; return n;
} }
@ -205,7 +207,9 @@ static ssize_t autosuspend_delay_ms_store(struct device *dev,
if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay) if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
return -EINVAL; return -EINVAL;
device_lock(dev);
pm_runtime_set_autosuspend_delay(dev, delay); pm_runtime_set_autosuspend_delay(dev, delay);
device_unlock(dev);
return n; return n;
} }

18
drivers/pci/pci-driver.c
View File

@ -18,6 +18,7 @@
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/cpu.h> #include <linux/cpu.h>
#include <linux/pm_runtime.h> #include <linux/pm_runtime.h>
#include <linux/suspend.h>
#include "pci.h" #include "pci.h"
struct pci_dynid { struct pci_dynid {
@ -615,6 +616,21 @@ static int pci_pm_prepare(struct device *dev)
struct device_driver *drv = dev->driver; struct device_driver *drv = dev->driver;
int error = 0; int error = 0;
/*
* If a PCI device configured to wake up the system from sleep states
* has been suspended at run time and there's a resume request pending
* for it, this is equivalent to the device signaling wakeup, so the
* system suspend operation should be aborted.
*/
pm_runtime_get_noresume(dev);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
if (pm_wakeup_pending()) {
pm_runtime_put_sync(dev);
return -EBUSY;
}
/* /*
* PCI devices suspended at run time need to be resumed at this * PCI devices suspended at run time need to be resumed at this
* point, because in general it is necessary to reconfigure them for * point, because in general it is necessary to reconfigure them for
@ -624,7 +640,7 @@ static int pci_pm_prepare(struct device *dev)
* system from the sleep state, we'll have to prevent it from signaling * system from the sleep state, we'll have to prevent it from signaling
* wake-up. * wake-up.
*/ */
pm_runtime_get_sync(dev); pm_runtime_resume(dev);
if (drv && drv->pm && drv->pm->prepare) if (drv && drv->pm && drv->pm->prepare)
error = drv->pm->prepare(dev); error = drv->pm->prepare(dev);

8
drivers/scsi/scsi_pm.c
View File

@ -144,9 +144,9 @@ int scsi_autopm_get_device(struct scsi_device *sdev)
int err; int err;
err = pm_runtime_get_sync(&sdev->sdev_gendev); err = pm_runtime_get_sync(&sdev->sdev_gendev);
if (err < 0) if (err < 0 && err !=-EACCES)
pm_runtime_put_sync(&sdev->sdev_gendev); pm_runtime_put_sync(&sdev->sdev_gendev);
else if (err > 0) else
err = 0; err = 0;
return err; return err;
} }
@ -173,9 +173,9 @@ int scsi_autopm_get_host(struct Scsi_Host *shost)
int err; int err;
err = pm_runtime_get_sync(&shost->shost_gendev); err = pm_runtime_get_sync(&shost->shost_gendev);
if (err < 0) if (err < 0 && err !=-EACCES)
pm_runtime_put_sync(&shost->shost_gendev); pm_runtime_put_sync(&shost->shost_gendev);
else if (err > 0) else
err = 0; err = 0;
return err; return err;
} }

6
include/linux/pm_runtime.h
View File

@ -82,6 +82,11 @@ static inline bool pm_runtime_suspended(struct device *dev)
&& !dev->power.disable_depth; && !dev->power.disable_depth;
} }
static inline bool pm_runtime_status_suspended(struct device *dev)
{
return dev->power.runtime_status == RPM_SUSPENDED;
}
static inline bool pm_runtime_enabled(struct device *dev) static inline bool pm_runtime_enabled(struct device *dev)
{ {
return !dev->power.disable_depth; return !dev->power.disable_depth;
@ -130,6 +135,7 @@ static inline void pm_runtime_put_noidle(struct device *dev) {}
static inline bool device_run_wake(struct device *dev) { return false; } static inline bool device_run_wake(struct device *dev) { return false; }
static inline void device_set_run_wake(struct device *dev, bool enable) {} static inline void device_set_run_wake(struct device *dev, bool enable) {}
static inline bool pm_runtime_suspended(struct device *dev) { return false; } static inline bool pm_runtime_suspended(struct device *dev) { return false; }
static inline bool pm_runtime_status_suspended(struct device *dev) { return false; }
static inline bool pm_runtime_enabled(struct device *dev) { return false; } static inline bool pm_runtime_enabled(struct device *dev) { return false; }
static inline int pm_generic_runtime_idle(struct device *dev) { return 0; } static inline int pm_generic_runtime_idle(struct device *dev) { return 0; }