18 May, 2011
3 commits
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Introduce generic .prepare() and .complete() power management
callbacks, currently missing, that can be used by subsystems and
power domains and export them. Provide NULL definitions of all
the generic system sleep callbacks for CONFIG_PM_SLEEP unset.Signed-off-by: Rafael J. Wysocki
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If device drivers allocate substantial amounts of memory (above 1 MB)
in their hibernate .freeze() callbacks (or in their legacy suspend
callbcks during hibernation), the subsequent creation of hibernate
image may fail due to the lack of memory. This is the case, because
the drivers' .freeze() callbacks are executed after the hibernate
memory preallocation has been carried out and the preallocated amount
of memory may be too small to cover the new driver allocations.
Unfortunately, the drivers' .prepare() callbacks also are executed
after the hibernate memory preallocation has completed, so they are
not suitable for allocating additional memory either. Thus the only
way a driver can safely allocate memory during hibernation is to use
a hibernate/suspend notifier. However, the notifiers are called
before the freezing of user space and the drivers wanting to use them
for allocating additional memory may not know how much memory needs
to be allocated at that point.To let device drivers overcome this difficulty rework the hibernation
sequence so that the memory preallocation is carried out after the
drivers' .prepare() callbacks have been executed, so that the
.prepare() callbacks can be used for allocating additional memory
to be used by the drivers' .freeze() callbacks. Update documentation
to match the new behavior of the code.Signed-off-by: Rafael J. Wysocki
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* power-domains:
PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset
PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"
OMAP1 / PM: Use generic clock manipulation routines for runtime PM
PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)
PM / Runtime: Add subsystem data field to struct dev_pm_info
OMAP2+ / PM: move runtime PM implementation to use device power domains
PM / Platform: Use generic runtime PM callbacks directly
shmobile: Use power domains for platform runtime PM
PM: Export platform bus type's default PM callbacks
PM: Make power domain callbacks take precedence over subsystem ones
12 May, 2011
1 commit
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Since suspend, resume and shutdown operations in struct sysdev_class
and struct sysdev_driver are not used any more, remove them. Also
drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used
for executing those operations and modify all of their users
accordingly. This reduces kernel code size quite a bit and reduces
its complexity.Signed-off-by: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman
29 Apr, 2011
1 commit
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Some subsystems need to attach PM-related data to struct device and
they need to use devres for this purpose. For their convenience
and to make code more straightforward, add a new field called
subsys_data to struct dev_pm_info and let subsystems use it for
attaching PM-related information to devices.Convert the ARM shmobile platform to using the new field.
Signed-off-by: Rafael J. Wysocki
24 Mar, 2011
1 commit
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Introduce Kconfig option allowing architectures where sysdev
operations used during system suspend, resume and shutdown have been
completely replaced with struct sycore_ops operations to avoid
building sysdev code that will never be used.Make callbacks in struct sys_device and struct sysdev_driver depend
on ARCH_NO_SYSDEV_OPS to allows us to verify if all of the references
have been actually removed from the code the given architecture
depends on.Make x86 select ARCH_NO_SYSDEV_OPS.
Signed-off-by: Rafael J. Wysocki
15 Mar, 2011
3 commits
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The platform bus type is often used to handle Systems-on-a-Chip (SoC)
where all devices are represented by objects of type struct
platform_device. In those cases the same "platform" device driver
may be used with multiple different system configurations, but the
actions needed to put the devices it handles into a low-power state
and back into the full-power state may depend on the design of the
given SoC. The driver, however, cannot possibly include all the
information necessary for the power management of its device on all
the systems it is used with. Moreover, the device hierarchy in its
current form also is not suitable for representing this kind of
information.The patch below attempts to address this problem by introducing
objects of type struct dev_power_domain that can be used for
representing power domains within a SoC. Every struct
dev_power_domain object provides a sets of device power
management callbacks that can be used to perform what's needed for
device power management in addition to the operations carried out by
the device's driver and subsystem.Namely, if a struct dev_power_domain object is pointed to by the
pwr_domain field in a struct device, the callbacks provided by its
ops member will be executed in addition to the corresponding
callbacks provided by the device's subsystem and driver during all
power transitions.Signed-off-by: Rafael J. Wysocki
Tested-and-acked-by: Kevin Hilman -
The variable pm_flags is used to prevent APM from being enabled
along with ACPI, which would lead to problems. However, acpi_init()
is always called before apm_init() and after acpi_init() has
returned, it is known whether or not ACPI will be used. Namely, if
acpi_disabled is not set after acpi_init() has returned, this means
that ACPI is enabled. Thus, it is sufficient to check acpi_disabled
in apm_init() to prevent APM from being enabled in parallel with
ACPI.Signed-off-by: Rafael J. Wysocki
Acked-by: Len Brown -
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.Signed-off-by: Rafael J. Wysocki
25 Feb, 2011
1 commit
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Commit 074037e (PM / Wakeup: Introduce wakeup source objects and
event statistics (v3)) caused ACPI wakeup to only work if
CONFIG_PM_SLEEP is set, but it also worked for CONFIG_PM_SLEEP unset
before. This can be fixed by making device_set_wakeup_enable(),
device_init_wakeup() and device_may_wakeup() work in the same way
as before commit 074037e when CONFIG_PM_SLEEP is unset.Reported-and-tested-by: Justin Maggard
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki
24 Dec, 2010
3 commits
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The pm_generic_ operations are all exported but are not prototyped in any
header file for direct use. Do so.[rjw: Added extern.]
Signed-off-by: Mark Brown
Signed-off-by: Rafael J. Wysocki -
The device power.status field is too complicated for its purpose
(storing the information about whether or not the device is in the
"active" state from the PM core's point of view), so replace it with
a bit field and modify all of its users accordingly.Signed-off-by: Rafael J. Wysocki
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This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers. Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held. This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended. This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki
17 Oct, 2010
4 commits
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This patch (as1427) implements the "autosuspend" facility for runtime
PM. A few new fields are added to the dev_pm_info structure and
several new PM helper functions are defined, for telling the PM core
whether or not a device uses autosuspend, for setting the autosuspend
delay, and for marking periods of device activity.Drivers that do not want to use autosuspend can continue using the
same helper functions as before; their behavior will not change. In
addition, drivers supporting autosuspend can also call the old helper
functions to get the old behavior.The details are all explained in Documentation/power/runtime_pm.txt
and Documentation/ABI/testing/sysfs-devices-power.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
Some devices, such as USB interfaces, cannot be power-managed
independently of their parents, i.e., they cannot be put in low power
while the parent remains at full power. This patch (as1425) creates a
new "no_callbacks" flag, which tells the PM core not to invoke the
runtime-PM callback routines for the such devices but instead to
assume that the callbacks always succeed. In addition, the
non-debugging runtime-PM sysfs attributes for the devices are removed,
since they are pretty much meaningless.The advantage of this scheme comes not so much from avoiding the
callbacks themselves, but rather from the fact that without the need
for a process context in which to run the callbacks, more work can be
done in interrupt context.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki -
There is a potential issue with the asynchronous suspend code that
a device driver suspending asynchronously may not notice that it
should back off. There are two failing scenarions, (1) when the
driver is waiting for a driver suspending synchronously to complete
and that second driver returns error code, in which case async_error
won't be set and the waiting driver will continue suspending and (2)
after the driver has called device_pm_wait_for_dev() and the waited
for driver returns error code, in which case the caller of
device_pm_wait_for_dev() will not know that there was an error and
will continue suspending.To fix this issue make __device_suspend() set async_error, so
async_suspend() doesn't need to set it any more, and make
device_pm_wait_for_dev() return async_error, so that its callers
can check whether or not they should continue suspending.No more changes are necessary, since device_pm_wait_for_dev() is
not used by any drivers' suspend routines.Reported-by: Colin Cross
Signed-off-by: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman -
Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.Signed-off-by: Rafael J. Wysocki
Acked-by: Greg Kroah-Hartman
19 Jul, 2010
2 commits
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In order for PowerTOP to be able to report how well the new runtime PM is
working for the various drivers, the kernel needs to export some basic
statistics in sysfs.This patch adds two sysfs files in the runtime PM domain that expose the
total time a device has been active, and the time a device has been
suspended.With this PowerTOP can compute the activity percentage
Active %age = 100 * (delta active) / (delta active + delta suspended)
and present the information to the user.
I've written the PowerTOP code (slated for version 1.12) already, and the
output looks like this:Runtime Device Power Management statistics
Active Device name
10.0% 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller[version 2: fix stat update bugs noticed by Alan Stern]
[version 3: rebase to -next and move the sysfs declaration]Signed-off-by: Arjan van de Ven
Signed-off-by: Rafael J. Wysocki -
One of the arguments during the suspend blockers discussion was that
the mainline kernel didn't contain any mechanisms making it possible
to avoid races between wakeup and system suspend.Generally, there are two problems in that area. First, if a wakeup
event occurs exactly when /sys/power/state is being written to, it
may be delivered to user space right before the freezer kicks in, so
the user space consumer of the event may not be able to process it
before the system is suspended. Second, if a wakeup event occurs
after user space has been frozen, it is not generally guaranteed that
the ongoing transition of the system into a sleep state will be
aborted.To address these issues introduce a new global sysfs attribute,
/sys/power/wakeup_count, associated with a running counter of wakeup
events and three helper functions, pm_stay_awake(), pm_relax(), and
pm_wakeup_event(), that may be used by kernel subsystems to control
the behavior of this attribute and to request the PM core to abort
system transitions into a sleep state already in progress.The /sys/power/wakeup_count file may be read from or written to by
user space. Reads will always succeed (unless interrupted by a
signal) and return the current value of the wakeup events counter.
Writes, however, will only succeed if the written number is equal to
the current value of the wakeup events counter. If a write is
successful, it will cause the kernel to save the current value of the
wakeup events counter and to abort the subsequent system transition
into a sleep state if any wakeup events are reported after the write
has returned.[The assumption is that before writing to /sys/power/state user space
will first read from /sys/power/wakeup_count. Next, user space
consumers of wakeup events will have a chance to acknowledge or
veto the upcoming system transition to a sleep state. Finally, if
the transition is allowed to proceed, /sys/power/wakeup_count will
be written to and if that succeeds, /sys/power/state will be written
to as well. Still, if any wakeup events are reported to the PM core
by kernel subsystems after that point, the transition will be
aborted.]Additionally, put a wakeup events counter into struct dev_pm_info and
make these per-device wakeup event counters available via sysfs,
so that it's possible to check the activity of various wakeup event
sources within the kernel.To illustrate how subsystems can use pm_wakeup_event(), make the
low-level PCI runtime PM wakeup-handling code use it.Signed-off-by: Rafael J. Wysocki
Acked-by: Jesse Barnes
Acked-by: Greg Kroah-Hartman
Acked-by: markgross
Reviewed-by: Alan Stern
07 Mar, 2010
1 commit
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There are subsystems whose power management callbacks only need to
invoke the callbacks provided by device drivers. Still, their system
sleep PM callbacks should play well with the runtime PM callbacks,
so that devices suspended at run time can be left in that state for
a system sleep transition.Provide a set of generic PM callbacks for such subsystems and
define convenience macros for populating dev_pm_ops structures.Signed-off-by: Rafael J. Wysocki
27 Feb, 2010
3 commits
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There are some dependencies between devices (in particular, between
EHCI USB controllers and their OHCI/UHCI siblings) which are not
reflected by the structure of the device tree. With synchronous
suspend and resume these dependencies are taken into accout
automatically, because the devices in question are always registered
in the right order, but to meet these constraints with asynchronous
suspend and resume the drivers of these devices will need to use
dpm_wait() in their suspend/resume routines, so introduce a helper
function allowing them to do that.Signed-off-by: Rafael J. Wysocki
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Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other. However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself. Analogously, we're not allowed to resume a device before
resuming its parent.The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices). For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
for the device or, in the case of devices with the
power.async_suspend flags unset, before executing the device's
suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
and device class suspend callbacks for the device, the PM core
waits for the completions of all the device's children to be
completed.
(4) During resume, right before running the bus type, device type and
device class resume callbacks for the device, the PM core waits
for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
after the bus type, device type and device class suspend (or
resume) callbacks executed for the device have returned.Signed-off-by: Rafael J. Wysocki
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Add new device sysfs attribute, power/control, allowing the user
space to block the run-time power management of the devices. If this
attribute is set to "on", the driver of the device won't be able to power
manage it at run time (without breaking the rules) and the device will
always be in the full power state (except when the entire system goes
into a sleep state).Signed-off-by: Rafael J. Wysocki
Acked-by: Alan Stern
16 Dec, 2009
1 commit
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Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Dec, 2009
1 commit
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Apparently, there are devices that can wake up the system from sleep
states and yet are incapable of generating wake-up events at run
time. Thus, introduce a flag indicating if given device is capable
of generating run-time wake-up events.Signed-off-by: Rafael J. Wysocki
15 Sep, 2009
1 commit
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In a number of cases, the .suspend, .freeze, .poweroff and .resume,
.thaw, .restore functions are identical. However, they all need to be
assigned to avoid regressionsm as the previous code called .suspend
resp. .resume in all those cases. SIMPLE_DEV_PM_OPS helps to deal
with this case.[rjw: Changed the name of the macro and added the comment explaining its
purpose.]Signed-off-by: Albin Tonnerre
Signed-off-by: Rafael J. Wysocki
23 Aug, 2009
1 commit
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Introduce a core framework for run-time power management of I/O
devices. Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level. Document all these things.Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.Signed-off-by: Rafael J. Wysocki
Acked-by: Magnus Damm
13 Jun, 2009
2 commits
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This patch (as1241) renames a bunch of functions in the PM core.
Rather than go through a boring list of name changes, suffice it to
say that in the end we have a bunch of pairs of functions:device_resume_noirq dpm_resume_noirq
device_resume dpm_resume
device_complete dpm_complete
device_suspend_noirq dpm_suspend_noirq
device_suspend dpm_suspend
device_prepare dpm_preparein which device_X does the X operation on a single device and dpm_X
invokes device_X for all devices in the dpm_list.In addition, the old dpm_power_up and device_resume_noirq have been
combined into a single function (dpm_resume_noirq).Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions
of the former top-level device_suspend and device_resume routines.Signed-off-by: Alan Stern
Acked-by: Magnus Damm
Signed-off-by: Rafael J. Wysocki -
Rename the functions performing "_noirq" dev_pm_ops
operations from device_power_down() and device_power_up()
to device_suspend_noirq() and device_resume_noirq().The new function names are chosen to show that the functions
are responsible for calling the _noirq() versions to finalize
the suspend/resume operation. The current function names do
not perform power down/up anymore so the names may be misleading.Global function renames:
- device_power_down() -> device_suspend_noirq()
- device_power_up() -> device_resume_noirq()Static function renames:
- suspend_device_noirq() -> __device_suspend_noirq()
- resume_device_noirq() -> __device_resume_noirq()Signed-off-by: Magnus Damm
Acked-by: Greg Kroah-Hartman
Acked-by: Len Brown
Signed-off-by: Rafael J. Wysocki
25 Mar, 2009
1 commit
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dpm_list currently relies on the fact that child devices will
be registered after their parents to get a correct suspend
order. Using device_move() however destroys this assumption, as
an already registered device may be moved under a newly registered
one.This patch adds a new argument to device_move(), allowing callers
to specify how dpm_list should be adapted.Signed-off-by: Cornelia Huck
Acked-by: Alan Stern
Signed-off-by: Greg Kroah-Hartman
23 Feb, 2009
1 commit
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Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.This is based on an earlier patch from Linus.
Signed-off-by: Rafael J. Wysocki
Signed-off-by: Linus Torvalds
07 Jan, 2009
2 commits
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This patch (as1167) fixes some misspellings in various recently-added
macros in pm.h. Fortunately these macros are not yet used anywhere.Signed-off-by: Alan Stern
Acked-by: Rafael J. Wysocki -
PM: Simplify the new suspend/hibernation framework for devices
Following the discussion at the Kernel Summit, simplify the new
device PM framework by merging 'struct pm_ops' and
'struct pm_ext_ops' and removing pointers to 'struct pm_ext_ops'
from 'struct platform_driver' and 'struct pci_driver'.After this change, the suspend/hibernation callbacks will only
reside in 'struct device_driver' as well as at the bus type/
device class/device type level. Accordingly, PCI and platform
device drivers are now expected to put their suspend/hibernation
callbacks into the 'struct device_driver' embedded in
'struct pci_driver' or 'struct platform_driver', respectively.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Cc: Jesse Barnes
Signed-off-by: Greg Kroah-Hartman
17 Oct, 2008
1 commit
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__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jul, 2008
4 commits
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This patch (as1112) adds some new PM_EVENT_* codes for use by kernel
subsystems. They describe runtime power-state transitions of the sort already
implemented by the USB subsystem.Signed-off-by: Alan Stern
Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Drop unnecessary includes from include/linux/pm.h .
Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the remaining obsolete definitions from include/linux/pm.h and move
the definitions of PM_SUSPEND and PM_RESUME to the header of h3600 which
is the only user of them.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the definition of 'struct pm_dev', which is not used any more,
along with some related stuff from include/linux/pm.h .Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jun, 2008
1 commit
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Introduce 'struct pm_ops' and 'struct pm_ext_ops' ('ext' meaning
'extended') representing suspend and hibernation operations for bus
types, device classes, device types and device drivers.Modify the PM core to use 'struct pm_ops' and 'struct pm_ext_ops'
objects, if defined, instead of the ->suspend(), ->resume(),
->suspend_late(), and ->resume_early() callbacks (the old callbacks
will be considered as legacy and gradually phased out).The main purpose of doing this is to separate suspend (aka S2RAM and
standby) callbacks from hibernation callbacks in such a way that the
new callbacks won't take arguments and the semantics of each of them
will be clearly specified. This has been requested for multiple
times by many people, including Linus himself, and the reason is that
within the current scheme if ->resume() is called, for example, it's
difficult to say why it's been called (ie. is it a resume from RAM or
from hibernation or a suspend/hibernation failure etc.?).The second purpose is to make the suspend/hibernation callbacks more
flexible so that device drivers can handle more than they can within
the current scheme. For example, some drivers may need to prevent
new children of the device from being registered before their
->suspend() callbacks are executed or they may want to carry out some
operations requiring the availability of some other devices, not
directly bound via the parent-child relationship, in order to prepare
for the execution of ->suspend(), etc.Ultimately, we'd like to stop using the freezing of tasks for suspend
and therefore the drivers' suspend/hibernation code will have to take
care of the handling of the user space during suspend/hibernation.
That, in turn, would be difficult within the current scheme, without
the new ->prepare() and ->complete() callbacks.Signed-off-by: Rafael J. Wysocki
Acked-by: Pavel Machek
Signed-off-by: Jesse Barnes
30 Apr, 2008
1 commit
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Remove the "#ifdef __KERNEL__" tests from unexported header files in
linux/include whose entire contents are wrapped in that preprocessor
test.Signed-off-by: Robert P. J. Day
Cc: David Woodhouse
Cc: Sam Ravnborg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
