PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter

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 <zhangqilong3@huawei.com>
Acked-by: Rafael J. Wysocki  <rafael.j.wysocki@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Zhang Qilong 2020-11-10 17:29:32 +08:00 committed by Jakub Kicinski
parent e2142ef266
commit dd8088d5a8

View File

@ -386,6 +386,27 @@ static inline int pm_runtime_get_sync(struct device *dev)
return __pm_runtime_resume(dev, RPM_GET_PUT);
}
/**
* pm_runtime_resume_and_get - Bump up usage counter of a device and resume it.
* @dev: Target device.
*
* Resume @dev synchronously and if that is successful, increment its runtime
* PM usage counter. Return 0 if the runtime PM usage counter of @dev has been
* incremented or a negative error code otherwise.
*/
static inline int pm_runtime_resume_and_get(struct device *dev)
{
int ret;
ret = __pm_runtime_resume(dev, RPM_GET_PUT);
if (ret < 0) {
pm_runtime_put_noidle(dev);
return ret;
}
return 0;
}
/**
* pm_runtime_put - Drop device usage counter and queue up "idle check" if 0.
* @dev: Target device.