1 files changed, 47 insertions, 14 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 32974b575e46..97c9a94a1a30 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -52,6 +52,7 @@ struct acpi_power_resource {
 	u32 system_level;
 	u32 order;
 	unsigned int ref_count;
+	unsigned int users;
 	bool wakeup_enabled;
 	struct mutex resource_lock;
 	struct list_head dependents;
@@ -147,6 +148,7 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 
 	for (i = start; i < package->package.count; i++) {
 		union acpi_object *element = &package->package.elements[i];
+		struct acpi_device *rdev;
 		acpi_handle rhandle;
 
 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
@@ -163,13 +165,16 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 		if (acpi_power_resource_is_dup(package, start, i))
 			continue;
 
-		err = acpi_add_power_resource(rhandle);
-		if (err)
+		rdev = acpi_add_power_resource(rhandle);
+		if (!rdev) {
+			err = -ENODEV;
 			break;
-
+		}
 		err = acpi_power_resources_list_add(rhandle, list);
 		if (err)
 			break;
+
+		to_power_resource(rdev)->users++;
 	}
 	if (err)
 		acpi_power_resources_list_free(list);
@@ -907,7 +912,7 @@ static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource
 	mutex_unlock(&power_resource_list_lock);
 }
 
-int acpi_add_power_resource(acpi_handle handle)
+struct acpi_device *acpi_add_power_resource(acpi_handle handle)
 {
 	struct acpi_power_resource *resource;
 	struct acpi_device *device = NULL;
@@ -918,11 +923,11 @@ int acpi_add_power_resource(acpi_handle handle)
 
 	acpi_bus_get_device(handle, &device);
 	if (device)
-		return 0;
+		return device;
 
 	resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 	if (!resource)
-		return -ENOMEM;
+		return NULL;
 
 	device = &resource->device;
 	acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER);
@@ -959,11 +964,11 @@ int acpi_add_power_resource(acpi_handle handle)
 
 	acpi_power_add_resource_to_list(resource);
 	acpi_device_add_finalize(device);
-	return 0;
+	return device;
 
  err:
 	acpi_release_power_resource(&device->dev);
-	return result;
+	return NULL;
 }
 
 #ifdef CONFIG_ACPI_SLEEP
@@ -995,8 +1000,40 @@ void acpi_resume_power_resources(void)
 
 	mutex_unlock(&power_resource_list_lock);
 }
+#endif
+
+static void acpi_power_turn_off_if_unused(struct acpi_power_resource *resource,
+				       bool init)
+{
+	if (resource->ref_count > 0)
+		return;
+
+	if (init) {
+		if (resource->users > 0)
+			return;
+	} else {
+		int result, state;
+
+		result = acpi_power_get_state(resource->device.handle, &state);
+		if (result || state == ACPI_POWER_RESOURCE_STATE_OFF)
+			return;
+	}
+
+	dev_info(&resource->device.dev, "Turning OFF\n");
+	__acpi_power_off(resource);
+}
 
-void acpi_turn_off_unused_power_resources(void)
+/**
+ * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
+ * @init: Control switch.
+ *
+ * If @ainit is set, unconditionally turn off all of the ACPI power resources
+ * without any users.
+ *
+ * Otherwise, turn off all ACPI power resources without active references (that
+ * is, the ones that should be "off" at the moment) that are "on".
+ */
+void acpi_turn_off_unused_power_resources(bool init)
 {
 	struct acpi_power_resource *resource;
 
@@ -1005,14 +1042,10 @@ void acpi_turn_off_unused_power_resources(void)
 	list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
 		mutex_lock(&resource->resource_lock);
 
-		if (!resource->ref_count) {
-			dev_info(&resource->device.dev, "Turning OFF\n");
-			__acpi_power_off(resource);
-		}
+		acpi_power_turn_off_if_unused(resource, init);
 
 		mutex_unlock(&resource->resource_lock);
 	}
 
 	mutex_unlock(&power_resource_list_lock);
 }
-#endif