---

yaml
---
r: 350939
b: refs/heads/master
c: b1c0f99
h: refs/heads/master
i:
  350937: c48fcf2
  350935: 298c04c
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 836aedb1414d4724b2ec68dd19810960c593720c
+refs/heads/master: b1c0f99bfb89cd9b42e3119ab822a8102fa87909

trunk/Documentation/ABI/testing/sysfs-devices-resource_in_use

@@ -0,0 +1,12 @@
+What:		/sys/devices/.../resource_in_use
+Date:		January 2013
+Contact:	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+		The /sys/devices/.../resource_in_use attribute is only present
+		for device objects representing ACPI power resources.
+
+		If present, it contains a number (0 or 1) representing the
+		current status of the given power resource (0 means that the
+		resource is not in use and therefore it has been turned off).
+
+		This attribute is read-only.

trunk/drivers/acpi/power.c

@@ -87,14 +87,20 @@ static DEFINE_MUTEX(power_resource_list_lock);
                              Power Resource Management
    -------------------------------------------------------------------------- */
 
+static inline
+struct acpi_power_resource *to_power_resource(struct acpi_device *device)
+{
+	return container_of(device, struct acpi_power_resource, device);
+}
+
 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
 {
 	struct acpi_device *device;
 
 	if (acpi_bus_get_device(handle, &device))
 		return NULL;
 
-	return container_of(device, struct acpi_power_resource, device);
+	return to_power_resource(device);
 }
 
 static int acpi_power_resources_list_add(acpi_handle handle,
@@ -678,6 +684,21 @@ static void acpi_release_power_resource(struct device *dev)
 	kfree(resource);
 }
 
+static ssize_t acpi_power_in_use_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf) {
+	struct acpi_power_resource *resource;
+
+	resource = to_power_resource(to_acpi_device(dev));
+	return sprintf(buf, "%u\n", !!resource->ref_count);
+}
+static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
+
+static void acpi_power_sysfs_remove(struct acpi_device *device)
+{
+	device_remove_file(&device->dev, &dev_attr_resource_in_use);
+}
+
 int acpi_add_power_resource(acpi_handle handle)
 {
 	struct acpi_power_resource *resource;
@@ -725,6 +746,9 @@ int acpi_add_power_resource(acpi_handle handle)
 	if (result)
 		goto err;
 
+	if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
+		device->remove = acpi_power_sysfs_remove;
+
 	mutex_lock(&power_resource_list_lock);
 	list_add(&resource->list_node, &acpi_power_resource_list);
 	mutex_unlock(&power_resource_list_lock);

trunk/drivers/acpi/scan.c

@@ -791,6 +791,9 @@ static void acpi_device_unregister(struct acpi_device *device)
 
 	acpi_power_add_remove_device(device, false);
 	acpi_device_remove_files(device);
+	if (device->remove)
+		device->remove(device);
+
 	device_del(&device->dev);
 	/*
 	 * Drop the reference counts of all power resources the device depends

trunk/include/acpi/acpi_bus.h

@@ -280,6 +280,7 @@ struct acpi_device {
 	struct mutex physical_node_lock;
 	DECLARE_BITMAP(physical_node_id_bitmap, ACPI_MAX_PHYSICAL_NODE);
 	struct list_head power_dependent;
+	void (*remove)(struct acpi_device *);
 };
 
 static inline void *acpi_driver_data(struct acpi_device *d)