static int mport_cdev_open()

in devices/rio_mport_cdev.c [1874:1933]

• 48 lines of code
• 5 McCabe index (conditional complexity)

static int mport_cdev_open(struct inode *inode, struct file *filp)
{
	int ret;
	int minor = iminor(inode);
	struct mport_dev *chdev;
	struct mport_cdev_priv *priv;

	/* Test for valid device */
	if (minor >= RIO_MAX_MPORTS) {
		rmcd_error("Invalid minor device number");
		return -EINVAL;
	}

	chdev = container_of(inode->i_cdev, struct mport_dev, cdev);

	rmcd_debug(INIT, "%s filp=%p", dev_name(&chdev->dev), filp);

	if (atomic_read(&chdev->active) == 0)
		return -ENODEV;

	get_device(&chdev->dev);

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		put_device(&chdev->dev);
		return -ENOMEM;
	}

	priv->md = chdev;

	mutex_lock(&chdev->file_mutex);
	list_add_tail(&priv->list, &chdev->file_list);
	mutex_unlock(&chdev->file_mutex);

	INIT_LIST_HEAD(&priv->db_filters);
	INIT_LIST_HEAD(&priv->pw_filters);
	spin_lock_init(&priv->fifo_lock);
	init_waitqueue_head(&priv->event_rx_wait);
	ret = kfifo_alloc(&priv->event_fifo,
			  sizeof(struct rio_event) * MPORT_EVENT_DEPTH,
			  GFP_KERNEL);
	if (ret < 0) {
		dev_err(&chdev->dev, DRV_NAME ": kfifo_alloc failed\n");
		ret = -ENOMEM;
		goto err_fifo;
	}

#ifdef CONFIG_RAPIDIO_DMA_ENGINE
	INIT_LIST_HEAD(&priv->async_list);
	spin_lock_init(&priv->req_lock);
	mutex_init(&priv->dma_lock);
#endif

	filp->private_data = priv;
	goto out;
err_fifo:
	kfree(priv);
out:
	return ret;
}