kernel.git/Documentation/power/runtime_pm.rst, branch linux-6.15.y

Documentation: PM: runtime: Fix a reference to pm_runtime_autosuspend()

2025-04-15T17:23:58Z

pm_runtime_autosuspend() got accidentally renamed as __pm_runtime_autosuspend() whereas the intention in the patch was to rename pm_runtime_put_autosuspend() only. Fix it. Fixes: b7d46644e554 ("PM: runtime: Add pm_runtime_put_autosuspend() replacement") Signed-off-by: Sakari Ailus Reviewed-by: Laurent Pinchart Link: https://patch.msgid.link/20250410153106.4146265-2-sakari.ailus@linux.intel.com Signed-off-by: Rafael J. Wysocki

Documentation: PM: Clarify pm_runtime_resume_and_get() return value

2024-12-10T19:14:22Z

Update the documentation to match the behaviour of the code. pm_runtime_resume_and_get() always returns 0 on success, even if __pm_runtime_resume() returns 1. Fixes: 2c412337cfe6 ("PM: runtime: Add documentation for pm_runtime_resume_and_get()") Signed-off-by: Paul Barker Link: https://patch.msgid.link/20241203143729.478-1-paul.barker.ct@bp.renesas.com [ rjw: Subject and changelog edits, adjusted new comment formatting ] Signed-off-by: Rafael J. Wysocki

Documentation: PM: Discourage use of deprecated macros

2024-09-04T12:37:57Z

The Documentation refers to some deprecated macros. Update those parts accordingly. Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20240903172520.3568731-1-andriy.shevchenko@linux.intel.com [ rjw: Changelog edit ] Signed-off-by: Rafael J. Wysocki

Documentation: PM: Fix runtime_pm.rst markdown syntax

2024-02-29T19:16:03Z

The '7. Generic subsystem callbacks' should be a section title, but the markdown syntax is not adequate now. Fix it so the chapter can be linked at docs.kernel.org correctly. Signed-off-by: Yiwei Lin [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

PM: runtime: Add pm_runtime_put_autosuspend() replacement

2024-02-12T15:57:47Z

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

2024-02-12T15:57:47Z

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: Capture device status before disabling runtime PM

2021-12-17T15:16:40Z

In some cases (for example, during system-wide suspend and resume of devices) it is useful to know whether or not runtime PM has ever been enabled for a given device and, if so, what the runtime PM status of it had been right before runtime PM was disabled for it last time. For this reason, introduce a new struct dev_pm_info field called last_status that will be used for capturing the runtime PM status of the device when its power.disable_depth counter changes from 0 to 1. The new field will be set to RPM_INVALID to start with and whenever power.disable_depth changes from 1 to 0, so it will be valid only when runtime PM of the device is currently disabled, but it has been enabled at least once. Immediately use power.last_status in rpm_resume() to make it handle the case when PM runtime is disabled for the device, but its runtime PM status is RPM_ACTIVE more consistently. Namely, make it return 1 if power.last_status is also equal to RPM_ACTIVE in that case (the idea being that if the status was RPM_ACTIVE last time when power.disable_depth was changing from 0 to 1 and it is still RPM_ACTIVE, it can be assumed to reflect what happened to the device last time when it was using runtime PM) and -EACCES otherwise. Update the documentation to provide a description of last_status and change the description of pm_runtime_resume() in it to reflect the new behavior of rpm_active(). While at it, rearrange the code in pm_runtime_enable() to be more straightforward and replace the WARN() macro in it with a pr_warn() invocation which is less disruptive. Link: https://lore.kernel.org/linux-pm/20211026222626.39222-1-ulf.hansson@linaro.org/t/#u Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: runtime: Clarify documentation when callbacks are unassigned

2021-06-11T17:04:07Z

Recent changes to the PM core allows ->runtime_suspend|resume callbacks to be unassigned. In the earlier behaviour the PM core would return -ENOSYS, when trying to runtime resume a device, for example. Let's update the documentation to clarify this. Signed-off-by: Ulf Hansson Acked-by: Alan Stern Signed-off-by: Rafael J. Wysocki

PM: runtime: document common mistake with pm_runtime_get_sync()

2021-05-31T12:17:13Z

pm_runtime_get_sync(), contradictory to intuition, does not drop the runtime PM usage counter on errors which lead to several wrong usages in drivers (missing the put). pm_runtime_resume_and_get() was added as a better implementation so document the preference of using it, hoping it will stop bad patterns. Suggested-by: Marek Szyprowski Signed-off-by: Krzysztof Kozlowski [ rjw: Documentation change edits ] Signed-off-by: Rafael J. Wysocki

PM: runtime: Add documentation for pm_runtime_resume_and_get()

2021-04-09T15:24:28Z

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") added a new runtime-PM API function without updating the documentation in runtime_pm.rst. Add the missing documentation. Signed-off-by: Alan Stern Fixes: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Signed-off-by: Rafael J. Wysocki