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-rw-r--r--Documentation/power/runtime_pm.txt6
-rw-r--r--drivers/base/power/runtime.c24
-rw-r--r--include/linux/pm_runtime.h5
3 files changed, 35 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
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index ab3fcd9f6c98..4c7055009bd6 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -966,6 +966,30 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
EXPORT_SYMBOL_GPL(__pm_runtime_resume);
/**
+ * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter.
+ * @dev: Device to handle.
+ *
+ * Return -EINVAL if runtime PM is disabled for the device.
+ *
+ * If that's not the case and if the device's 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.
+ */
+int pm_runtime_get_if_in_use(struct device *dev)
+{
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = dev->power.disable_depth > 0 ? -EINVAL :
+ dev->power.runtime_status == RPM_ACTIVE
+ && atomic_inc_not_zero(&dev->power.usage_count);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
+
+/**
* __pm_runtime_set_status - Set runtime PM status of a device.
* @dev: Device to handle.
* @status: New runtime PM status of the device.
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 3bdbb4189780..7af093d6a4dd 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -39,6 +39,7 @@ extern int pm_runtime_force_resume(struct device *dev);
extern int __pm_runtime_idle(struct device *dev, int rpmflags);
extern int __pm_runtime_suspend(struct device *dev, int rpmflags);
extern int __pm_runtime_resume(struct device *dev, int rpmflags);
+extern int pm_runtime_get_if_in_use(struct device *dev);
extern int pm_schedule_suspend(struct device *dev, unsigned int delay);
extern int __pm_runtime_set_status(struct device *dev, unsigned int status);
extern int pm_runtime_barrier(struct device *dev);
@@ -143,6 +144,10 @@ static inline int pm_schedule_suspend(struct device *dev, unsigned int delay)
{
return -ENOSYS;
}
+static inline int pm_runtime_get_if_in_use(struct device *dev)
+{
+ return -EINVAL;
+}
static inline int __pm_runtime_set_status(struct device *dev,
unsigned int status) { return 0; }
static inline int pm_runtime_barrier(struct device *dev) { return 0; }