From: Zhang Qilong zhangqilong3@huawei.com
[ Upstream commit dd8088d5a8969dc2b42f71d7bc01c25c61a78066 ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/pm_runtime.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
--- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -387,6 +387,27 @@ static inline int pm_runtime_get_sync(st }
/** + * 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. *