Re: [PATCHv4 04/11] PM: Use *_dec_not_zero instead of *_add_unless

Rafael J. Wysocki
2011-07-27T19:49:18Z

On Wednesday, July 27, 2011, Sven Eckelmann wrote:
> atomic_dec_not_zero is defined for each architecture through
> <linux/atomic.h> to provide the functionality of
> atomic_add_unless(x, -1, 0).
>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> Cc: Len Brown <len.brown@intel.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Rafael J. Wysocki <rjw@sisk.pl>
> Cc: linux-pm@lists.linux-foundation.org

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>

> ---
> drivers/base/power/runtime.c | 4 ++--
> include/linux/pm_runtime.h | 2 +-
> kernel/power/hibernate.c | 4 ++--
> kernel/power/user.c | 2 +-
> 4 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 8dc247c..bda10d9 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -401,7 +401,7 @@ static int rpm_suspend(struct device *dev, int rpmflags)
>
> if (dev->parent) {
> parent = dev->parent;
> - atomic_add_unless(&parent->power.child_count, -1, 0);
> + atomic_dec_not_zero(&parent->power.child_count);
> }
> }
> wake_up_all(&dev->power.wait_queue);
> @@ -841,7 +841,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
> if (status == RPM_SUSPENDED) {
> /* It always is possible to set the status to 'suspended'. */
> if (parent) {
> - atomic_add_unless(&parent->power.child_count, -1, 0);
> + atomic_dec_not_zero(&parent->power.child_count);
> notify_parent = !parent->power.ignore_children;
> }
> goto out_set;
> diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
> index daac05d..3b4931c 100644
> --- a/include/linux/pm_runtime.h
> +++ b/include/linux/pm_runtime.h
> @@ -63,7 +63,7 @@ static inline void pm_runtime_get_noresume(struct device *dev)
>
> static inline void pm_runtime_put_noidle(struct device *dev)
> {
> - atomic_add_unless(&dev->power.usage_count, -1, 0);
> + atomic_dec_not_zero(&dev->power.usage_count);
> }
>
> static inline bool device_run_wake(struct device *dev)
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index 8f7b1db..0ba8d87 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -606,7 +606,7 @@ int hibernate(void)
>
> mutex_lock(&pm_mutex);
> /* The snapshot device should not be opened while we're running */
> - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
> + if (!atomic_dec_not_zero(&snapshot_device_available)) {
> error = -EBUSY;
> goto Unlock;
> }
> @@ -756,7 +756,7 @@ static int software_resume(void)
> goto Unlock;
>
> /* The snapshot device should not be opened while we're running */
> - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
> + if (!atomic_dec_not_zero(&snapshot_device_available)) {
> error = -EBUSY;
> swsusp_close(FMODE_READ);
> goto Unlock;
> diff --git a/kernel/power/user.c b/kernel/power/user.c
> index 42ddbc6..1c1cc01 100644
> --- a/kernel/power/user.c
> +++ b/kernel/power/user.c
> @@ -72,7 +72,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
>
> mutex_lock(&pm_mutex);
>
> - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
> + if (!atomic_dec_not_zero(&snapshot_device_available)) {
> error = -EBUSY;
> goto Unlock;
> }
>