From 3afd8df024339c7da1a5a0302f3987866dd16e40 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 22 Dec 2025 21:36:25 +0100 Subject: PM: runtime: Change pm_runtime_put() return type to void The primary role of pm_runtime_put() is to decrement the runtime PM usage counter of the given device. It always does that regardless of the value returned by it later. In addition, if the runtime PM usage counter after decrementation turns out to be zero, a work item is queued up to check whether or not the device can be suspended. This is not guaranteed to succeed though and even if it is successful, the device may still not be suspended going forward. There are multiple valid reasons why pm_runtime_put() may not decide to queue up the work item mentioned above, including, but not limited to, the case when user space has written "on" to the device's runtime PM "control" file in sysfs. In all of those cases, pm_runtime_put() returns a negative error code (even though the device's runtime PM usage counter has been successfully decremented by it) which is very confusing. In fact, its return value should only be used for debug purposes and care should be taken when doing it even in that case. Accordingly, to avoid the confusion mentioned above, change the return type of pm_runtime_put() to void. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Brian Norris Link: https://patch.msgid.link/14387202.RDIVbhacDa@rafael.j.wysocki --- include/linux/pm_runtime.h | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 41037c513f06..64921b10ac74 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -545,22 +545,10 @@ static inline int pm_runtime_resume_and_get(struct device *dev) * * Decrement the runtime PM usage counter of @dev and if it turns out to be * equal to 0, queue up a work item for @dev like in pm_request_idle(). - * - * Return: - * * 1: Success. Usage counter dropped to zero, but device was already suspended. - * * 0: Success. - * * -EINVAL: Runtime PM error. - * * -EACCES: Runtime PM disabled. - * * -EAGAIN: Runtime PM usage counter became non-zero or Runtime PM status - * change ongoing. - * * -EBUSY: Runtime PM child_count non-zero. - * * -EPERM: Device PM QoS resume latency 0. - * * -EINPROGRESS: Suspend already in progress. - * * -ENOSYS: CONFIG_PM not enabled. */ -static inline int pm_runtime_put(struct device *dev) +static inline void pm_runtime_put(struct device *dev) { - return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC); + __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC); } /** -- cgit v1.2.3