static int stm_source_link_add()

in stm/core.c [989:1048]

• 42 lines of code
• 6 McCabe index (conditional complexity)

static int stm_source_link_add(struct stm_source_device *src,
			       struct stm_device *stm)
{
	char *ids[] = { NULL, "default", NULL };
	int err = -ENOMEM;

	mutex_lock(&stm->link_mutex);
	spin_lock(&stm->link_lock);
	spin_lock(&src->link_lock);

	/* src->link is dereferenced under stm_source_srcu but not the list */
	rcu_assign_pointer(src->link, stm);
	list_add_tail(&src->link_entry, &stm->link_list);

	spin_unlock(&src->link_lock);
	spin_unlock(&stm->link_lock);
	mutex_unlock(&stm->link_mutex);

	ids[0] = kstrdup(src->data->name, GFP_KERNEL);
	if (!ids[0])
		goto fail_detach;

	err = stm_assign_first_policy(stm, &src->output, ids,
				      src->data->nr_chans);
	kfree(ids[0]);

	if (err)
		goto fail_detach;

	/* this is to notify the STM device that a new link has been made */
	if (stm->data->link)
		err = stm->data->link(stm->data, src->output.master,
				      src->output.channel);

	if (err)
		goto fail_free_output;

	/* this is to let the source carry out all necessary preparations */
	if (src->data->link)
		src->data->link(src->data);

	return 0;

fail_free_output:
	stm_output_free(stm, &src->output);

fail_detach:
	mutex_lock(&stm->link_mutex);
	spin_lock(&stm->link_lock);
	spin_lock(&src->link_lock);

	rcu_assign_pointer(src->link, NULL);
	list_del_init(&src->link_entry);

	spin_unlock(&src->link_lock);
	spin_unlock(&stm->link_lock);
	mutex_unlock(&stm->link_mutex);

	return err;
}