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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-12-17 02:54:26 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-12-21 03:11:12 +0100
commita436b6a19f57656a6557439523923d89eb4a880d (patch)
tree62637a13b7721a775f8aa2af4554c9fc3069f595 /Documentation/power/runtime_pm.txt
parentd89d7ff9edf58cbf8ad0f490694b2edea8eb3a39 (diff)
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PM / runtime: Add new helper for conditional usage count incrementation
Introduce a new runtime PM function, pm_runtime_get_if_in_use(), that will increment the device's runtime PM usage counter and return 1 if its status is RPM_ACTIVE and its usage counter is greater than 0 at the same time (0 will be returned otherwise). This is useful for things that should only be done if the device is active (from the runtime PM perspective) and used by somebody (as indicated by the usage counter) already and they are not worth bothering otherwise. Requested-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/power/runtime_pm.txt')
-rw-r--r--Documentation/power/runtime_pm.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 0784bc3a2ab5..7328cf85236c 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -371,6 +371,12 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
- increment the device's usage counter, run pm_runtime_resume(dev) and
return its result
+ int pm_runtime_get_if_in_use(struct device *dev);
+ - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
+ runtime PM status is RPM_ACTIVE and the runtime PM usage counter is
+ nonzero, increment the counter and return 1; otherwise return 0 without
+ changing the counter
+
void pm_runtime_put_noidle(struct device *dev);
- decrement the device's usage counter