From c58e7ed28b4534ed073371843d03c433d6a9fe34 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Wed, 26 May 2021 12:22:51 -0400 Subject: PM: runtime: document common mistake with pm_runtime_get_sync() 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 --- include/linux/pm_runtime.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 6c08a085367b..aab8b35e9f8a 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -380,6 +380,9 @@ static inline int pm_runtime_get(struct device *dev) * The possible return values of this function are the same as for * pm_runtime_resume() and the runtime PM usage counter of @dev remains * incremented in all cases, even if it returns an error code. + * Consider using pm_runtime_resume_and_get() instead of it, especially + * if its return value is checked by the caller, as this is likely to result + * in cleaner code. */ static inline int pm_runtime_get_sync(struct device *dev) { -- cgit v1.2.3