int coresight_enable()

in coresight/coresight-core.c [1089:1166]
53 lines of code
10 McCabe index (conditional complexity)

int coresight_enable(struct coresight_device *csdev)
{
	int cpu, ret = 0;
	struct coresight_device *sink;
	struct list_head *path;
	enum coresight_dev_subtype_source subtype;

	subtype = csdev->subtype.source_subtype;

	mutex_lock(&coresight_mutex);

	ret = coresight_validate_source(csdev, __func__);
	if (ret)
		goto out;

	if (csdev->enable) {
		/*
		 * There could be multiple applications driving the software
		 * source. So keep the refcount for each such user when the
		 * source is already enabled.
		 */
		if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
			atomic_inc(csdev->refcnt);
		goto out;
	}

	sink = coresight_get_enabled_sink(csdev);
	if (!sink) {
		ret = -EINVAL;
		goto out;
	}

	path = coresight_build_path(csdev, sink);
	if (IS_ERR(path)) {
		pr_err("building path(s) failed\n");
		ret = PTR_ERR(path);
		goto out;
	}

	ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
	if (ret)
		goto err_path;

	ret = coresight_enable_source(csdev, CS_MODE_SYSFS);
	if (ret)
		goto err_source;

	switch (subtype) {
	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
		/*
		 * When working from sysFS it is important to keep track
		 * of the paths that were created so that they can be
		 * undone in 'coresight_disable()'.  Since there can only
		 * be a single session per tracer (when working from sysFS)
		 * a per-cpu variable will do just fine.
		 */
		cpu = source_ops(csdev)->cpu_id(csdev);
		per_cpu(tracer_path, cpu) = path;
		break;
	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
		stm_path = path;
		break;
	default:
		/* We can't be here */
		break;
	}

out:
	mutex_unlock(&coresight_mutex);
	return ret;

err_source:
	coresight_disable_path(path);

err_path:
	coresight_release_path(path);
	goto out;
}