PM / Domains: Move syscore flag from subsys data to struct device

The syscore device PM flag is used to mark the devices (belonging to
a PM domain) that should never be turned off, except for the sy

PM / Domains: Move syscore flag from subsys data to struct device

The syscore device PM flag is used to mark the devices (belonging to
a PM domain) that should never be turned off, except for the system
core (syscore) suspend/hibernation and resume stages. That flag is
stored in the device's struct pm_subsys_data object whose address is
available from struct device. However, in some situations it may be
convenient to set that flag before the device is added to a PM
domain, so it is better to move it directly to the "power" member of
struct device. Then, it can be checked by the routines in
drivers/base/power/runtime.c and drivers/base/power/main.c, which is
more straightforward.

This also reduces the number of dev_gpd_data() invocations in the
generic PM domains framework, so the overhead related to the syscore
flag is slightly smaller.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>

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PM / Runtime: Check device PM QoS setting before "no callbacks" check

If __dev_pm_qos_read_value(dev) returns a negative value,
rpm_suspend() should return -EPERM for dev even if its
power.no_callba

PM / Runtime: Check device PM QoS setting before "no callbacks" check

If __dev_pm_qos_read_value(dev) returns a negative value,
rpm_suspend() should return -EPERM for dev even if its
power.no_callbacks flag is set. For this to happen, the device's
power.no_callbacks flag has to be checked after the PM QoS check,
so move the PM QoS check to rpm_check_suspend_allowed() (this will
make it cover idle notifications as well as runtime suspend too).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

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PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()

The power.deferred_resume can only be set if the runtime PM status
of device is RPM_SUSPENDING and it should be cleared after it

PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()

The power.deferred_resume can only be set if the runtime PM status
of device is RPM_SUSPENDING and it should be cleared after its
status has been changed, regardless of whether or not the runtime
suspend has been successful. However, it only is cleared on
suspend failure, while it may remain set on successful suspend and
is happily leaked to rpm_resume() executed in that case.

That shouldn't happen, so if power.deferred_resume is set in
rpm_suspend() after the status has been changed to RPM_SUSPENDED,
clear it before calling rpm_resume(). Then, it doesn't need to be
cleared before changing the status to RPM_SUSPENDING any more,
because it's always cleared after the status has been changed to
either RPM_SUSPENDED (on success) or RPM_ACTIVE (on failure).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

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PM / Runtime: Fix rpm_resume() return value for power.no_callbacks set

For devices whose power.no_callbacks flag is set, rpm_resume()
should return 1 if the device's parent is already active, so tha

PM / Runtime: Fix rpm_resume() return value for power.no_callbacks set

For devices whose power.no_callbacks flag is set, rpm_resume()
should return 1 if the device's parent is already active, so that
the callers of pm_runtime_get() don't think that they have to wait
for the device to resume (asynchronously) in that case (the core
won't queue up an asynchronous resume in that case, so there's
nothing to wait for anyway).

Modify the code accordingly (and make sure that an idle notification
will be queued up on success, even if 1 is to be returned).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

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PM / Runtime: Remove device fields related to suspend time, v2

After the previous changes in default_stop_ok() and
default_power_down_ok() for PM domains, there are two fields in
struct dev_pm_info

PM / Runtime: Remove device fields related to suspend time, v2

After the previous changes in default_stop_ok() and
default_power_down_ok() for PM domains, there are two fields in
struct dev_pm_info that aren't necessary any more, suspend_time
and max_time_suspended_ns.

Remove those fields along with all of the code that accesses them,
which simplifies the runtime PM framework quite a bit.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: don't forget to wake up waitqueue on failure

This patch (as1535) fixes a bug in the runtime PM core. When a
runtime suspend attempt completes, whether successfully or not, the
device'

PM / Runtime: don't forget to wake up waitqueue on failure

This patch (as1535) fixes a bug in the runtime PM core. When a
runtime suspend attempt completes, whether successfully or not, the
device's power.wait_queue is supposed to be signalled. But this
doesn't happen in the failure pathway of rpm_suspend() when another
autosuspend attempt is rescheduled. As a result, a task can get stuck
indefinitely on the wait queue (I have seen this happen in testing).

The patch fixes the problem by moving the wake_up_all() call up near
the start of the failure code.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM: Run the driver callback directly if the subsystem one is not there

Make the PM core execute driver PM callbacks directly if the
corresponding subsystem callbacks are not present.

There are thre

PM: Run the driver callback directly if the subsystem one is not there

Make the PM core execute driver PM callbacks directly if the
corresponding subsystem callbacks are not present.

There are three reasons for doing that. First, it reflects the
behavior of drivers/base/dd.c:really_probe() that runs the driver's
.probe() callback directly if the bus type's one is not defined, so
this change will remove one arbitrary difference between the PM core
and the remaining parts of the driver core. Second, it will allow
some subsystems, whose PM callbacks don't do anything except for
executing driver callbacks, to be simplified quite a bit by removing
those "forward-only" callbacks. Finally, it will allow us to remove
one level of indirection in the system suspend and resume code paths
where it is not necessary, which is going to lead to less debug noise
with initcall_debug passed in the kernel command line (messages won't
be printed for driverless devices whose subsystems don't provide
PM callbacks among other things).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Use device PM QoS constraints (v2)

Make the runtime PM core use device PM QoS constraints to check if
it is allowed to suspend a given device, so that an error code is
returned if the

PM / Runtime: Use device PM QoS constraints (v2)

Make the runtime PM core use device PM QoS constraints to check if
it is allowed to suspend a given device, so that an error code is
returned if the device's own PM QoS constraint is negative or one of
its children has already been suspended for too long. If this is
not the case, the maximum estimated time the device is allowed to be
suspended, computed as the minimum of the device's PM QoS constraint
and the PM QoS constraints of its children (reduced by the difference
between the current time and their suspend times) is stored in a new
device's PM field power.max_time_suspended_ns that can be used by
the device's subsystem or PM domain to decide whether or not to put
the device into lower-power (and presumably higher-latency) states
later (if the constraint is 0, which means "no constraint", the
power.max_time_suspended_ns is set to -1).

Additionally, the time of execution of the subsystem-level
.runtime_suspend() callback for the device is recorded in the new
power.suspend_time field for later use by the device's subsystem or
PM domain along with power.max_time_suspended_ns (it also is used
by the core code when the device's parent is suspended).

Introduce a new helper function,
pm_runtime_update_max_time_suspended(), allowing subsystems and PM
domains (or device drivers) to update the power.max_time_suspended_ns
field, for example after changing the power state of a suspended
device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Automatically retry failed autosuspends

Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed. The idle callback routine could
then schedul

PM / Runtime: Automatically retry failed autosuspends

Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed. The idle callback routine could
then schedule a delayed suspend for some time later.

However this behavior was changed by commit
f71648d73c1650b8b4aceb3856bebbde6daa3b86 (PM / Runtime: Remove idle
notification after failing suspend). No notifications were sent, and
there was no clear mechanism to retry failed suspends.

This caused problems for the usbhid driver, because it fails
autosuspend attempts as long as a key is being held down. Therefore
this patch (as1492) adds a mechanism for retrying failed
autosuspends. If the callback routine updates the last_busy field so
that the next autosuspend expiration time is in the future, the
autosuspend will automatically be rescheduled.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Cc: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Fix runtime accounting calculation error

With delta type being int, its value is made zero
for all values of now > 0x80000000.
Hence fixing it.

Signed-off-by: venu byravarasu <vbyrava

PM / Runtime: Fix runtime accounting calculation error

With delta type being int, its value is made zero
for all values of now > 0x80000000.
Hence fixing it.

Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.

Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broke

drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.

Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broken
soon.

[ with input from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

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PM / Runtime: Handle .runtime_suspend() failure correctly

If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should
still be in ACTIVE state, so it is not necessary to send an idle
notifica

PM / Runtime: Handle .runtime_suspend() failure correctly

If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should
still be in ACTIVE state, so it is not necessary to send an idle
notification to its parent. If .runtime_suspend() returns other
fatal failure, it doesn't make sense to send idle notification to
its parent.

Skip parent idle notification when failure is returned from
.runtime_suspend() and update comments in rpm_suspend() to reflect
that change.

[rjw: Modified the subject and changelog slightly.]

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Fix kerneldoc comment for rpm_suspend()

This patch fix kerneldoc comments for rpm_suspend():

- 'Cancel a pending idle notification' should be put before, also
should be changed to

PM / Runtime: Fix kerneldoc comment for rpm_suspend()

This patch fix kerneldoc comments for rpm_suspend():

- 'Cancel a pending idle notification' should be put before, also
should be changed to 'Cancel a pending idle notification,
autosuspend or suspend'.

- idle notification for the device after succeeding suspend has
been removed, so update the comment accordingly.

[rjw: Modified the subject and changelog slightly.]

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Replace dev_dbg() with trace_rpm_*()

This patch replaces dev_dbg with trace_rpm_* inside
the three important functions:

rpm_idle
rpm_suspend
rpm_resume

Trace points have the below

PM / Runtime: Replace dev_dbg() with trace_rpm_*()

This patch replaces dev_dbg with trace_rpm_* inside
the three important functions:

rpm_idle
rpm_suspend
rpm_resume

Trace points have the below advantages compared with dev_dbg:

- trace points include much runtime information(such as
running cpu, current task, ...)

- most of linux distributions may disable "verbose debug"
driver debug compile switch, so it is very difficult to
report/debug runtime pm related problems from distribution
users without this kind of debug information.

- for upstream kernel users, enableing the debug switch will
produce many useless "rpm_resume" output, and it is very noise.

- dev_dbg inside rpm_suspend/rpm_resume may have some effects
on runtime pm behaviour of console devicer

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Don't run callbacks under lock for power.irq_safe set

The rpm_suspend() and rpm_resume() routines execute subsystem or PM
domain callbacks under power.lock if power.irq_safe is set for

PM / Runtime: Don't run callbacks under lock for power.irq_safe set

The rpm_suspend() and rpm_resume() routines execute subsystem or PM
domain callbacks under power.lock if power.irq_safe is set for the
given device. This is inconsistent with that rpm_idle() does after
commit 02b2677 (PM / Runtime: Allow _put_sync() from
interrupts-disabled context) and is problematic for subsystems and PM
domains wanting to use power.lock for synchronization in their
runtime PM callbacks.

This change requires the code checking if the device's runtime PM
status is RPM_SUSPENDING or RPM_RESUMING to be modified too, to take
the power.irq_safe set case into account (that code wasn't reachable
before with power.irq_safe set, because it's executed with the
device's power.lock held).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>

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PM / Runtime: Add might_sleep() to runtime PM functions

Some of the entry points to pm runtime are not safe to
call in atomic context unless pm_runtime_irq_safe() has
been called. Inspecting the co

PM / Runtime: Add might_sleep() to runtime PM functions

Some of the entry points to pm runtime are not safe to
call in atomic context unless pm_runtime_irq_safe() has
been called. Inspecting the code, it is not immediately
obvious that the functions sleep at all, as they run
inside a spin_lock_irqsave, but under some conditions
they can drop the lock and turn on irqs.

If a driver incorrectly calls the pm_runtime apis, it can
cause sleeping and irq processing when it expects to stay
in atomic context.

Add might_sleep_if to the majority of the __pm_runtime_* entry points
to enforce correct usage.

Add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Allow _put_sync() from interrupts-disabled context

Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock

PM / Runtime: Allow _put_sync() from interrupts-disabled context

Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks. This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.

This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.

However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.

Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.

Reported-by: Colin Cross <ccross@google.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Consistent utilization of deferred_resume

dev->power.deferred_resume is used as a bool typically, so change
one assignment to false from 0, like other places.

Signed-off-by: ShuoX Liu

PM / Runtime: Consistent utilization of deferred_resume

dev->power.deferred_resume is used as a bool typically, so change
one assignment to false from 0, like other places.

Signed-off-by: ShuoX Liu <shuox.liu@intel.com>

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PM / Runtime: Replace "run-time" with "runtime" in documentation

The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time"). Replace all of those
in

PM / Runtime: Replace "run-time" with "runtime" in documentation

The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time"). Replace all of those
instances with "runtime" to make the naming consistent.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Runtime: Return special error code if runtime PM is disabled

Some callers of pm_runtime_get_sync() and other runtime PM helper
functions, scsi_autopm_get_host() and scsi_autopm_get_device() in

PM / Runtime: Return special error code if runtime PM is disabled

Some callers of pm_runtime_get_sync() and other runtime PM helper
functions, scsi_autopm_get_host() and scsi_autopm_get_device() in
particular, need to distinguish error codes returned when runtime PM
is disabled (i.e. power.disable_depth is nonzero for the given
device) from error codes returned in other situations. For this
reason, make the runtime PM helper functions return -EACCES when
power.disable_depth is nonzero and ensure that this error code
won't be returned by them in any other circumstances. Modify
scsi_autopm_get_host() and scsi_autopm_get_device() to check the
error code returned by pm_runtime_get_sync() and ignore -EACCES.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

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PM / Domains: Rename struct dev_power_domain to struct dev_pm_domain

The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced

PM / Domains: Rename struct dev_power_domain to struct dev_pm_domain

The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced the
struct dev_power_domain type for representing device power domains,
evidently confuses some developers who tend to think that objects
of this type must correspond to "power domains" as defined by
hardware, which is not the case. Namely, at the kernel level, a
struct dev_power_domain object can represent arbitrary set of devices
that are mutually dependent power management-wise and need not belong
to one hardware power domain. To avoid that confusion, rename struct
dev_power_domain to struct dev_pm_domain and rename the related
pointers in struct device and struct pm_clk_notifier_block from
pwr_domain to pm_domain.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>

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PM: Make power domain callbacks take precedence over subsystem ones

Change the PM core's behavior related to power domains in such a way
that, if a power domain is defined for a given device, its ca

PM: Make power domain callbacks take precedence over subsystem ones

Change the PM core's behavior related to power domains in such a way
that, if a power domain is defined for a given device, its callbacks
will be executed instead of and not in addition to the device
subsystem's PM callbacks.

The idea behind the initial implementation of power domains handling
by the PM core was that power domain callbacks would be executed in
addition to subsystem callbacks, so that it would be possible to
extend the subsystem callbacks by using power domains. It turns out,
however, that this wouldn't be really convenient in some important
situations.

For example, there are systems in which power can only be removed
from entire power domains. On those systems it is not desirable to
execute device drivers' PM callbacks until it is known that power is
going to be removed from the devices in question, which means that
they should be executed by power domain callbacks rather then by
subsystem (e.g. bus type) PM callbacks, because subsystems generally
have no information about what devices belong to which power domain.
Thus, for instance, if the bus type in question is the platform bus
type, its PM callbacks generally should not be called in addition to
power domain callbacks, because they run device drivers' callbacks
unconditionally if defined.

While in principle the default subsystem PM callbacks, or a subset of
them, may be replaced with different functions, it doesn't seem
correct to do so, because that would change the subsystem's behavior
with respect to all devices in the system, regardless of whether or
not they belong to any power domains. Thus, the only remaining
option is to make power domain callbacks take precedence over
subsystem callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Kevin Hilman <khilman@ti.com>

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Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

PM: Make system-wide PM and runtime PM treat subsystems consistently

The code handling system-wide power transitions (eg. suspend-to-RAM)
can in theory execute callbacks provided by the device's bus

PM: Make system-wide PM and runtime PM treat subsystems consistently

The code handling system-wide power transitions (eg. suspend-to-RAM)
can in theory execute callbacks provided by the device's bus type,
device type and class in each phase of the power transition. In
turn, the runtime PM core code only calls one of those callbacks at
a time, preferring bus type callbacks to device type or class
callbacks and device type callbacks to class callbacks.

It seems reasonable to make them both behave in the same way in that
respect. Moreover, even though a device may belong to two subsystems
(eg. bus type and device class) simultaneously, in practice power
management callbacks for system-wide power transitions are always
provided by only one of them (ie. if the bus type callbacks are
defined, the device class ones are not and vice versa). Thus it is
possible to modify the code handling system-wide power transitions
so that it follows the core runtime PM code (ie. treats the
subsystem callbacks as mutually exclusive).

On the other hand, the core runtime PM code will choose to execute,
for example, a runtime suspend callback provided by the device type
even if the bus type's struct dev_pm_ops object exists, but the
runtime_suspend pointer in it happens to be NULL. This is confusing,
because it may lead to the execution of callbacks from different
subsystems during different operations (eg. the bus type suspend
callback may be executed during runtime suspend of the device, while
the device type callback will be executed during system suspend).

Make all of the power management code treat subsystem callbacks in
a consistent way, such that:
(1) If the device's type is defined (eg. dev->type is not NULL)
and its pm pointer is not NULL, the callbacks from dev->type->pm
will be used.
(2) If dev->type is NULL or dev->type->pm is NULL, but the device's
class is defined (eg. dev->class is not NULL) and its pm pointer
is not NULL, the callbacks from dev->class->pm will be used.
(3) If dev->type is NULL or dev->type->pm is NULL and dev->class is
NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm
will be used provided that both dev->bus and dev->bus->pm are
not NULL.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Reasoning-sounds-sane-to: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

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PM: Add support for device power domains

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

PM: Add support for device power domains

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 <rjw@sisk.pl>
Tested-and-acked-by: Kevin Hilman <khilman@ti.com>

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