int most_start_channel()

in core.c [1090:1151]

• 52 lines of code
• 10 McCabe index (conditional complexity)

int most_start_channel(struct most_interface *iface, int id,
		       struct most_component *comp)
{
	int num_buffer;
	int ret;
	struct most_channel *c = iface->p->channel[id];

	if (unlikely(!c))
		return -EINVAL;

	mutex_lock(&c->start_mutex);
	if (c->pipe0.refs + c->pipe1.refs > 0)
		goto out; /* already started by another component */

	if (!try_module_get(iface->mod)) {
		dev_err(&c->dev, "Failed to acquire HDM lock\n");
		mutex_unlock(&c->start_mutex);
		return -ENOLCK;
	}

	c->cfg.extra_len = 0;
	if (c->iface->configure(c->iface, c->channel_id, &c->cfg)) {
		dev_err(&c->dev, "Channel configuration failed. Go check settings...\n");
		ret = -EINVAL;
		goto err_put_module;
	}

	init_waitqueue_head(&c->hdm_fifo_wq);

	if (c->cfg.direction == MOST_CH_RX)
		num_buffer = arm_mbo_chain(c, c->cfg.direction,
					   most_read_completion);
	else
		num_buffer = arm_mbo_chain(c, c->cfg.direction,
					   most_write_completion);
	if (unlikely(!num_buffer)) {
		ret = -ENOMEM;
		goto err_put_module;
	}

	ret = run_enqueue_thread(c, id);
	if (ret)
		goto err_put_module;

	c->is_starving = 0;
	c->pipe0.num_buffers = c->cfg.num_buffers / 2;
	c->pipe1.num_buffers = c->cfg.num_buffers - c->pipe0.num_buffers;
	atomic_set(&c->mbo_ref, num_buffer);

out:
	if (comp == c->pipe0.comp)
		c->pipe0.refs++;
	if (comp == c->pipe1.comp)
		c->pipe1.refs++;
	mutex_unlock(&c->start_mutex);
	return 0;

err_put_module:
	module_put(iface->mod);
	mutex_unlock(&c->start_mutex);
	return ret;
}