linux-stable.git/include/linux/pm_runtime.h, branch v6.15.2

PM: runtime: Convert pm_runtime_blocked() to static inline

2025-03-03T13:35:07+00:00

The comment in pm_runtime_blocked() is acutally wrong: power.last_status
is not a bit field.  Its data type is an enum and so one can reasonably
assume that partial updates of it will not be observed.

Accordingly, pm_runtime_blocked() can be converted to a static inline
function and the related locking overhead can be eliminated, so long
as it is only used in system suspend/resume code paths because
power.last_status is not expected to be updated concurrently while
that code is running.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/1923449.tdWV9SEqCh@rjwysocki.net

PM: sleep: Adjust check before setting power.must_resume

2025-03-03T13:31:47+00:00

The check before setting power.must_resume in device_suspend_noirq()
does not take power.child_count into account, but it should do that, so
use pm_runtime_need_not_resume() in it for this purpose and adjust the
comment next to it accordingly.

Fixes: 107d47b2b95e ("PM: sleep: core: Simplify the SMART_SUSPEND flag handling")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/3353728.44csPzL39Z@rjwysocki.net

PM: sleep: Avoid unnecessary checks in device_prepare_smart_suspend()

2025-03-03T12:29:00+00:00

Add an optimization (on top of previous changes) to avoid calling
pm_runtime_blocked(), which involves acquiring the device's PM spinlock,
for devices with no PM callbacks and runtime PM "blocked".

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/2978873.e9J7NaK4W3@rjwysocki.net

PM: runtime: Introduce pm_runtime_blocked()

2025-02-18T20:43:06+00:00

Introduce a new helper function called pm_runtime_blocked()
for checking the power.last_status value indicating whether or not
enabling runtime PM for the given device has been blocked (which
happens in the "prepare" phase of system-wide suspend if runtime
PM is disabled for the given device at that point).

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/4632087.LvFx2qVVIh@rjwysocki.net

PM: Block enabling of runtime PM during system suspend

2025-02-18T20:43:06+00:00

If device_prepare() runs on a device that has never had runtime
PM enabled so far, it may reasonably assume that runtime PM will
not be enabled for that device during the system suspend-resume
cycle currently in progress, but this has never been guaranteed.

To verify this assumption, make device_prepare() arrange for
triggering a device warning accompanied by a call trace dump if
runtime PM is enabled for such a device after it has returned.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/6131109.lOV4Wx5bFT@rjwysocki.net

PM: Rearrange documentation related to __pm_runtime_disable()

2025-02-18T20:01:31+00:00

There are only two callers of __pm_runtime_disable(), one of which is
device_suspend_late() and the other is pm_runtime_disable() that has
its own kerneldoc comment and there are no plans to add any more of
them.  Since they use different values of the __pm_runtime_disable()
second parameter, the actual code behavior is different in each case,
but it is all documented in the __pm_runtime_disable() kerneldoc comment
which is not particularly straightforward.

For this reason, move the information from the __pm_runtime_disable()
kerneldoc comment to the pm_runtime_disable() one and into a separate
comment in device_suspend_late() and remove the __pm_runtime_disable()
kerneldoc comment altogether.

No functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Ulf Hansson 
Link: https://patch.msgid.link/12617588.O9o76ZdvQC@rjwysocki.net

PM: runtime: Add pm_runtime_put_autosuspend() replacement

2024-02-12T15:57:47+00:00

Add __pm_runtime_put_autosuspend() that replaces
pm_runtime_put_autosuspend() for new users. The intent is to later
re-purpose pm_runtime_put_autosuspend() to also mark the device's last
busy stamp---which is what the vast majority of users actually need.

This is also described in pm_runtime_put_autosuspend() documentation.

Signed-off-by: Sakari Ailus 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Rafael J. Wysocki

PM: runtime: Simplify pm_runtime_get_if_active() usage

2024-02-12T15:57:47+00:00

There are two ways to opportunistically increment a device's runtime PM
usage count, calling either pm_runtime_get_if_active() or
pm_runtime_get_if_in_use(). The former has an argument to tell whether to
ignore the usage count or not, and the latter simply calls the former with
ign_usage_count set to false. The other users that want to ignore the
usage_count will have to explicitly set that argument to true which is a
bit cumbersome.

To make this function more practical to use, remove the ign_usage_count
argument from the function. The main implementation is in a static
function called pm_runtime_get_conditional() and implementations of
pm_runtime_get_if_active() and pm_runtime_get_if_in_use() are moved to
runtime.c.

Signed-off-by: Sakari Ailus 
Reviewed-by: Alex Elder 
Reviewed-by: Laurent Pinchart 
Acked-by: Takashi Iwai  # sound/
Reviewed-by: Jacek Lawrynowicz  # drivers/accel/ivpu/
Acked-by: Rodrigo Vivi  # drivers/gpu/drm/i915/
Reviewed-by: Rodrigo Vivi 
Acked-by: Bjorn Helgaas  # drivers/pci/
Signed-off-by: Rafael J. Wysocki

PM: runtime: Remove unsued extern declaration of pm_runtime_update_max_time_suspended()

2023-08-22T19:31:57+00:00

Commit 76e267d822f2 ("PM / Runtime: Remove device fields related to
suspend time, v2") left behind this.

Signed-off-by: YueHaibing 
Signed-off-by: Rafael J. Wysocki

PM: Improve EXPORT_*_DEV_PM_OPS macros

2022-10-04T18:52:38+00:00

Update the _EXPORT_DEV_PM_OPS() internal macro. It was not used anywhere
outside pm.h and pm_runtime.h, so it is safe to update it.

Before, this macro would take a few parameters to be used as sleep and
runtime callbacks. This made it unsuitable to use with different
callbacks, for instance the "noirq" ones.

It is now semantically different: instead of creating a conditionally
exported dev_pm_ops structure, it only contains part of the definition.

This macro should however never be used directly (hence the trailing
underscore). Instead, the following four macros are provided:
- EXPORT_DEV_PM_OPS(name)
- EXPORT_GPL_DEV_PM_OPS(name)
- EXPORT_NS_DEV_PM_OPS(name, ns)
- EXPORT_NS_GPL_DEV_PM_OPS(name, ns)

For instance, it is now possible to conditionally export noirq
suspend/resume PM functions like this:

EXPORT_GPL_DEV_PM_OPS(foo_pm_ops) = {
    NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
};

The existing helper macros EXPORT_*_SIMPLE_DEV_PM_OPS() and
EXPORT_*_RUNTIME_DEV_PM_OPS() have been updated to use these new macros.

Signed-off-by: Paul Cercueil 
Reviewed-by: Jonathan Cameron 
Signed-off-by: Rafael J. Wysocki