int led_trigger_set()

in led-triggers.c [158:238]

• 65 lines of code
• 13 McCabe index (conditional complexity)

int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
{
	char *event = NULL;
	char *envp[2];
	const char *name;
	int ret;

	if (!led_cdev->trigger && !trig)
		return 0;

	name = trig ? trig->name : "none";
	event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);

	/* Remove any existing trigger */
	if (led_cdev->trigger) {
		spin_lock(&led_cdev->trigger->leddev_list_lock);
		list_del_rcu(&led_cdev->trig_list);
		spin_unlock(&led_cdev->trigger->leddev_list_lock);

		/* ensure it's no longer visible on the led_cdevs list */
		synchronize_rcu();

		cancel_work_sync(&led_cdev->set_brightness_work);
		led_stop_software_blink(led_cdev);
		if (led_cdev->trigger->deactivate)
			led_cdev->trigger->deactivate(led_cdev);
		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
		led_cdev->trigger = NULL;
		led_cdev->trigger_data = NULL;
		led_cdev->activated = false;
		led_set_brightness(led_cdev, LED_OFF);
	}
	if (trig) {
		spin_lock(&trig->leddev_list_lock);
		list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);
		spin_unlock(&trig->leddev_list_lock);
		led_cdev->trigger = trig;

		if (trig->activate)
			ret = trig->activate(led_cdev);
		else
			ret = 0;

		if (ret)
			goto err_activate;

		ret = device_add_groups(led_cdev->dev, trig->groups);
		if (ret) {
			dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
			goto err_add_groups;
		}
	}

	if (event) {
		envp[0] = event;
		envp[1] = NULL;
		if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
			dev_err(led_cdev->dev,
				"%s: Error sending uevent\n", __func__);
		kfree(event);
	}

	return 0;

err_add_groups:

	if (trig->deactivate)
		trig->deactivate(led_cdev);
err_activate:

	spin_lock(&led_cdev->trigger->leddev_list_lock);
	list_del_rcu(&led_cdev->trig_list);
	spin_unlock(&led_cdev->trigger->leddev_list_lock);
	synchronize_rcu();
	led_cdev->trigger = NULL;
	led_cdev->trigger_data = NULL;
	led_set_brightness(led_cdev, LED_OFF);
	kfree(event);

	return ret;
}