Re: [PATCH v11 1/4] usb: Add support for Intel LJCA device

[Oliver Neukum <oneukum@suse.com>]

On 29.08.23 06:54, Wentong Wu wrote:

> +static void ljca_recv(struct urb *urb)
> +{
> +	struct ljca_msg *header = urb->transfer_buffer;
> +	struct ljca_adapter *adap = urb->context;
> +	int ret;
> +
> +	if (urb->status) {
> +		/* sync/async unlink faults aren't errors */
> +		if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
> +		    urb->status == -ESHUTDOWN)
> +			return;
> +
> +		dev_err(adap->dev, "recv urb error: %d\n", urb->status);
> +		goto resubmit;
> +	}
> +
> +	if (header->len + sizeof(*header) != urb->actual_length)
> +		goto resubmit;
> +
> +	if (header->flags & LJCA_ACK_FLAG)
> +		ljca_handle_cmd_ack(adap, header);
> +	else
> +		ljca_handle_event(adap, header);
> +
> +resubmit:
> +	ret = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (ret)
> +		dev_err(adap->dev, "resubmit recv urb error %d\n", ret);

This will detect an error if you get an unlucky timing with ljca_suspend().
The correct test would be:
if (ret && ret != -EPERM)

	HTH
		Oliver