static int mcba_usb_start(struct mcba_priv *priv)
{
	struct net_device *netdev = priv->netdev;
	int err, i;

	mcba_init_ctx(priv);

	for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
		struct urb *urb = NULL;
		u8 *buf;
		dma_addr_t buf_dma;

		/* create a URB, and a buffer for it */
		urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!urb) {
			err = -ENOMEM;
			break;
		}

		buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
					 GFP_KERNEL, &buf_dma);
		if (!buf) {
			netdev_err(netdev, "No memory left for USB buffer\n");
			usb_free_urb(urb);
			err = -ENOMEM;
			break;
		}

		urb->transfer_dma = buf_dma;

		usb_fill_bulk_urb(urb, priv->udev,
				  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
				  buf, MCBA_USB_RX_BUFF_SIZE,
				  mcba_usb_read_bulk_callback, priv);
		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		usb_anchor_urb(urb, &priv->rx_submitted);

		err = usb_submit_urb(urb, GFP_KERNEL);
		if (err) {
			usb_unanchor_urb(urb);
			usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
					  buf, buf_dma);
			usb_free_urb(urb);
			break;
		}

		priv->rxbuf[i] = buf;
		priv->rxbuf_dma[i] = buf_dma;

		/* Drop reference, USB core will take care of freeing it */
		usb_free_urb(urb);
	}

	/* Did we submit any URBs */
	if (i == 0) {
		netdev_warn(netdev, "couldn't setup read URBs\n");
		return err;
	}

	/* Warn if we've couldn't transmit all the URBs */
	if (i < MCBA_MAX_RX_URBS)
		netdev_warn(netdev, "rx performance may be slow\n");

	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);

	return err;
}
static int mcba_usb_start(struct mcba_priv *priv)
{
	struct net_device *netdev = priv->netdev;
	int err, i;

	mcba_init_ctx(priv);

	for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
		struct urb *urb = NULL;
		u8 *buf;
		dma_addr_t buf_dma;

		 
		urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!urb) {
			err = -ENOMEM;
			break;
		}

		buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
					 GFP_KERNEL, &buf_dma);
		if (!buf) {
			netdev_err(netdev, "No memory left for USB buffer\n");
			usb_free_urb(urb);
			err = -ENOMEM;
			break;
		}

		urb->transfer_dma = buf_dma;

		usb_fill_bulk_urb(urb, priv->udev,
				  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
				  buf, MCBA_USB_RX_BUFF_SIZE,
				  mcba_usb_read_bulk_callback, priv);
		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		usb_anchor_urb(urb, &priv->rx_submitted);

		err = usb_submit_urb(urb, GFP_KERNEL);
		if (err) {
			usb_unanchor_urb(urb);
			usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
					  buf, buf_dma);
			usb_free_urb(urb);
			break;
		}

		priv->rxbuf[i] = buf;
		priv->rxbuf_dma[i] = buf_dma;

		 
		usb_free_urb(urb);
	}

	 
	if (i == 0) {
		netdev_warn(netdev, "couldn't setup read URBs\n");
		return err;
	}

	 
	if (i < MCBA_MAX_RX_URBS)
		netdev_warn(netdev, "rx performance may be slow\n");

	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);

	return err;
}