user/sven/linux.git/include/linux/pm_runtime.h, branch v5.15.26

PM: runtime: Add safety net to supplier device release

2022-01-27T10:04:44Z

[ Upstream commit d1579e61192e0e686faa4208500ef4c3b529b16c ] Because refcount_dec_not_one() returns true if the target refcount becomes saturated, it is generally unsafe to use its return value as a loop termination condition, but that is what happens when a device link's supplier device is released during runtime PM suspend operations and on device link removal. To address this, introduce pm_runtime_release_supplier() to be used in the above cases which will check the supplier device's runtime PM usage counter in addition to the refcount_dec_not_one() return value, so the loop can be terminated in case the rpm_active refcount value becomes invalid, and update the code in question to use it as appropriate. This change is not expected to have any visible functional impact. Reported-by: Peter Zijlstra Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Peter Zijlstra (Intel) Signed-off-by: Sasha Levin

PM: runtime: Fix pm_runtime_active() kerneldoc comment

2021-12-14T09:57:16Z

commit 444dd878e85fb33fcfb2682cfdab4c236f33ea3e upstream. The kerneldoc comment of pm_runtime_active() does not reflect the behavior of the function, so update it accordingly. Fixes: 403d2d116ec0 ("PM: runtime: Add kerneldoc comments to multiple helpers") Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

PM: runtime: add devm_pm_runtime_enable helper

2021-08-26T18:27:51Z

A typical code pattern for pm_runtime_enable() call is to call it in the _probe function and to call pm_runtime_disable() both from _probe error path and from _remove function. For some drivers the whole remove function would consist of the call to pm_remove_disable(). Add helper function to replace this bolierplate piece of code. Calling devm_pm_runtime_enable() removes the need for calling pm_runtime_disable() both in the probe()'s error path and in the remove() function. Signed-off-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20210731195034.979084-2-dmitry.baryshkov@linaro.org Acked-by: Rafael J. Wysocki Signed-off-by: Stephen Boyd

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: Replace inline function pm_runtime_callbacks_present()

2021-04-08T17:14:46Z

Commit 9a7875461fd0 ("PM: runtime: Replace pm_runtime_callbacks_present()") forgot to change the inline version. Fixes: 9a7875461fd0 ("PM: runtime: Replace pm_runtime_callbacks_present()") Signed-off-by: YueHaibing Signed-off-by: Rafael J. Wysocki

PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter

2020-11-16T17:37:01Z

In many case, we need to check return value of pm_runtime_get_sync, but it brings a trouble to the usage counter processing. Many callers forget to decrease the usage counter when it failed, which could resulted in reference leak. It has been discussed a lot[0][1]. So we add a function to deal with the usage counter for better coding. [0]https://lkml.org/lkml/2020/6/14/88 [1]https://patchwork.ozlabs.org/project/linux-tegra/list/?series=178139 Signed-off-by: Zhang Qilong Acked-by: Rafael J. Wysocki Signed-off-by: Jakub Kicinski

PM: runtime: Drop pm_runtime_clean_up_links()

2020-11-02T17:14:07Z

After commit d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()") nothing prevents the consumer device's runtime PM from acquiring additional references to the supplier device after pm_runtime_clean_up_links() has run (or even while it is running), so calling this function from __device_release_driver() may be pointless (or even harmful). Moreover, it ignores stateless device links, so the runtime PM handling of managed and stateless device links is inconsistent because of it, so better get rid of it entirely. Fixes: d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()") Signed-off-by: Rafael J. Wysocki Cc: 5.1+ # 5.1+ Tested-by: Xiang Chen Reviewed-by: Greg Kroah-Hartman

PM: runtime: Drop runtime PM references to supplier on link removal

2020-11-02T17:14:07Z

While removing a device link, drop the supplier device's runtime PM usage counter as many times as needed to drop all of the runtime PM references to it from the consumer in addition to dropping the consumer's link count. Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki Cc: 5.1+ # 5.1+ Tested-by: Xiang Chen Reviewed-by: Greg Kroah-Hartman

PM: runtime: Fix typo in pm_runtime_set_active() helper comment

2020-10-20T17:45:14Z

This patch is to fix typo in the comment of helper pm_runtime_set_active(). Signed-off-by: Bean Huo [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki

PM: runtime: Add kerneldoc comments to multiple helpers

2020-08-04T10:39:28Z

Add kerneldoc comments to multiple PM-runtime helper functions defined as static inline wrappers around lower-level routines to provide quick reference decumentation of their behavior. Some of them are similar to each other with subtle differences only and the behavior of some of them may appear as counter-intuitive, so clarify all that to avoid confusion. Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Reviewed-by: Sakari Ailus