Merge branch 'power-refcount' into release

drivers/acpi/power.c

@@ -80,18 +80,13 @@ static struct acpi_driver acpi_power_driver = {
 		},
 };
 
-struct acpi_power_reference {
-	struct list_head node;
-	struct acpi_device *device;
-};
-
 struct acpi_power_resource {
 	struct acpi_device * device;
 	acpi_bus_id name;
 	u32 system_level;
 	u32 order;
+	unsigned int ref_count;
 	struct mutex resource_lock;
-	struct list_head reference;
 };
 
 static struct list_head acpi_power_resource_list;
@@ -184,101 +179,89 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 	return result;
 }
 
-static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
+static int __acpi_power_on(struct acpi_power_resource *resource)
 {
-	int result = 0;
-	int found = 0;
 	acpi_status status = AE_OK;
-	struct acpi_power_resource *resource = NULL;
-	struct list_head *node, *next;
-	struct acpi_power_reference *ref;
 
+	status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	/* Update the power resource's _device_ power state */
+	resource->device->power.state = ACPI_STATE_D0;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
+			  resource->name));
+
+	return 0;
+}
+
+static int acpi_power_on(acpi_handle handle)
+{
+	int result = 0;
+	struct acpi_power_resource *resource = NULL;
 
 	result = acpi_power_get_context(handle, &resource);
 	if (result)
 		return result;
 
 	mutex_lock(&resource->resource_lock);
-	list_for_each_safe(node, next, &resource->reference) {
-		ref = container_of(node, struct acpi_power_reference, node);
-		if (dev->handle == ref->device->handle) {
-			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
-				  dev->pnp.bus_id, resource->name));
-			found = 1;
-			break;
-		}
-	}
 
-	if (!found) {
-		ref = kmalloc(sizeof (struct acpi_power_reference),
-		    irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
-		if (!ref) {
-			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
-			mutex_unlock(&resource->resource_lock);
-			return -ENOMEM;
-		}
-		list_add_tail(&ref->node, &resource->reference);
-		ref->device = dev;
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
-			  dev->pnp.bus_id, resource->name));
+	if (resource->ref_count++) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Power resource [%s] already on",
+				  resource->name));
+	} else {
+		result = __acpi_power_on(resource);
 	}
-	mutex_unlock(&resource->resource_lock);
 
-	status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
-
-	/* Update the power resource's _device_ power state */
-	resource->device->power.state = ACPI_STATE_D0;
+	mutex_unlock(&resource->resource_lock);
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
-			  resource->name));
 	return 0;
 }
 
-static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
+static int acpi_power_off_device(acpi_handle handle)
 {
 	int result = 0;
 	acpi_status status = AE_OK;
 	struct acpi_power_resource *resource = NULL;
-	struct list_head *node, *next;
-	struct acpi_power_reference *ref;
 
 	result = acpi_power_get_context(handle, &resource);
 	if (result)
 		return result;
 
 	mutex_lock(&resource->resource_lock);
-	list_for_each_safe(node, next, &resource->reference) {
-		ref = container_of(node, struct acpi_power_reference, node);
-		if (dev->handle == ref->device->handle) {
-			list_del(&ref->node);
-			kfree(ref);
-			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
-			    dev->pnp.bus_id, resource->name));
-			break;
-		}
+
+	if (!resource->ref_count) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Power resource [%s] already off",
+				  resource->name));
+		goto unlock;
 	}
 
-	if (!list_empty(&resource->reference)) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
-		    resource->name));
-		mutex_unlock(&resource->resource_lock);
-		return 0;
+	if (--resource->ref_count) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Power resource [%s] still in use\n",
+				  resource->name));
+		goto unlock;
 	}
-	mutex_unlock(&resource->resource_lock);
 
 	status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
+	if (ACPI_FAILURE(status)) {
+		result = -ENODEV;
+	} else {
+		/* Update the power resource's _device_ power state */
+		resource->device->power.state = ACPI_STATE_D3;
 
-	/* Update the power resource's _device_ power state */
-	resource->device->power.state = ACPI_STATE_D3;
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Power resource [%s] turned off\n",
+				  resource->name));
+	}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
-			  resource->name));
+ unlock:
+	mutex_unlock(&resource->resource_lock);
 
-	return 0;
+	return result;
 }
 
 /**
@@ -364,7 +347,7 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 
 	/* Open power resource */
 	for (i = 0; i < dev->wakeup.resources.count; i++) {
-		int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
+		int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 		if (ret) {
 			printk(KERN_ERR PREFIX "Transition power state\n");
 			dev->wakeup.flags.valid = 0;
@@ -420,7 +403,7 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 	/* Close power resource */
 	for (i = 0; i < dev->wakeup.resources.count; i++) {
 		int ret = acpi_power_off_device(
-				dev->wakeup.resources.handles[i], dev);
+				dev->wakeup.resources.handles[i]);
 		if (ret) {
 			printk(KERN_ERR PREFIX "Transition power state\n");
 			dev->wakeup.flags.valid = 0;
@@ -500,7 +483,7 @@ int acpi_power_transition(struct acpi_device *device, int state)
 	 * (e.g. so the device doesn't lose power while transitioning).
 	 */
 	for (i = 0; i < tl->count; i++) {
-		result = acpi_power_on(tl->handles[i], device);
+		result = acpi_power_on(tl->handles[i]);
 		if (result)
 			goto end;
 	}
@@ -513,7 +496,7 @@ int acpi_power_transition(struct acpi_device *device, int state)
 	 * Then we dereference all power resources used in the current list.
 	 */
 	for (i = 0; i < cl->count; i++) {
-		result = acpi_power_off_device(cl->handles[i], device);
+		result = acpi_power_off_device(cl->handles[i]);
 		if (result)
 			goto end;
 	}
@@ -551,7 +534,6 @@ static int acpi_power_add(struct acpi_device *device)
 
 	resource->device = device;
 	mutex_init(&resource->resource_lock);
-	INIT_LIST_HEAD(&resource->reference);
 	strcpy(resource->name, device->pnp.bus_id);
 	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
@@ -594,22 +576,14 @@ static int acpi_power_add(struct acpi_device *device)
 
 static int acpi_power_remove(struct acpi_device *device, int type)
 {
-	struct acpi_power_resource *resource = NULL;
-	struct list_head *node, *next;
+	struct acpi_power_resource *resource;
 
-
-	if (!device || !acpi_driver_data(device))
+	if (!device)
 		return -EINVAL;
 
 	resource = acpi_driver_data(device);
-
-	mutex_lock(&resource->resource_lock);
-	list_for_each_safe(node, next, &resource->reference) {
-		struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
-		list_del(&ref->node);
-		kfree(ref);
-	}
-	mutex_unlock(&resource->resource_lock);
+	if (!resource)
+		return -EINVAL;
 
 	kfree(resource);
 
@@ -619,29 +593,28 @@ static int acpi_power_remove(struct acpi_device *device, int type)
 static int acpi_power_resume(struct acpi_device *device)
 {
 	int result = 0, state;
-	struct acpi_power_resource *resource = NULL;
-	struct acpi_power_reference *ref;
+	struct acpi_power_resource *resource;
 
-	if (!device || !acpi_driver_data(device))
+	if (!device)
 		return -EINVAL;
 
 	resource = acpi_driver_data(device);
+	if (!resource)
+		return -EINVAL;
+
+	mutex_lock(&resource->resource_lock);
 
 	result = acpi_power_get_state(device->handle, &state);
 	if (result)
-		return result;
+		goto unlock;
 
-	mutex_lock(&resource->resource_lock);
-	if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
-	    !list_empty(&resource->reference)) {
-		ref = container_of(resource->reference.next, struct acpi_power_reference, node);
-		mutex_unlock(&resource->resource_lock);
-		result = acpi_power_on(device->handle, ref->device);
-		return result;
-	}
+	if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
+		result = __acpi_power_on(resource);
 
+ unlock:
 	mutex_unlock(&resource->resource_lock);
-	return 0;
+
+	return result;
 }
 
 int __init acpi_power_init(void)