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Commit 7c88f9f4 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: usbduxfast: introduce usbduxfast_ai_handle_urb() 



Factor the urb handling and resubmit out of the completion handler and
tidy it up. This allows a common exit path to be used in the completion
handler to stop the async command and handle the events.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Reviewed-by: default avatarBernd Porr <mail@berndporr.me.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 41ca22a8

drivers/staging/comedi/drivers/usbduxfast.c

+52 −79
Original line number Diff line number Diff line
@@ -236,114 +236,87 @@ static int usbduxfast_ai_cancel(struct comedi_device *dev, 
	return ret;

}



/*

 * analogue IN

 * interrupt service routine

 */

static void usbduxfast_ai_handle_urb(struct comedi_device *dev,

				     struct comedi_subdevice *s,

				     struct urb *urb)

{

	struct usbduxfast_private *devpriv = dev->private;

	struct comedi_async *async = s->async;

	struct comedi_cmd *cmd = &async->cmd;

	int ret;



	if (devpriv->ignore) {

		devpriv->ignore--;

	} else {

		unsigned int nbytes = urb->actual_length;



		if (cmd->stop_src == TRIG_COUNT) {

			unsigned int nsamples = nbytes / bytes_per_sample(s);



			if (devpriv->ai_sample_count < nsamples) {

				nsamples = devpriv->ai_sample_count;

				async->events |= COMEDI_CB_EOA;

			}

			devpriv->ai_sample_count -= nsamples;

			nbytes = nsamples * bytes_per_sample(s);

		}



		cfc_write_array_to_buffer(s, urb->transfer_buffer, nbytes);

	}



	/* if command is still running, resubmit urb for BULK transfer */

	if (!(async->events & COMEDI_CB_CANCEL_MASK)) {

		urb->dev = comedi_to_usb_dev(dev);

		urb->status = 0;

		ret = usb_submit_urb(urb, GFP_ATOMIC);

		if (ret < 0) {

			dev_err(dev->class_dev, "urb resubm failed: %d", ret);

			async->events |= COMEDI_CB_ERROR;

		}

	}

}



static void usbduxfast_ai_interrupt(struct urb *urb)

{

	struct comedi_device *dev = urb->context;

	struct comedi_subdevice *s = dev->read_subdev;

	struct comedi_async *async = s->async;

	struct comedi_cmd *cmd = &async->cmd;

	struct usb_device *usb = comedi_to_usb_dev(dev);

	struct usbduxfast_private *devpriv = dev->private;

	int n, err;



	/* are we running a command? */

	if (unlikely(!devpriv->ai_cmd_running)) {

		/*

		 * not running a command

		 * do not continue execution if no asynchronous command

		 * is running in particular not resubmit

		 */

	/* exit if not running a command, do not resubmit urb */

	if (!devpriv->ai_cmd_running)

		return;

	}



	/* first we test if something unusual has just happened */

	switch (urb->status) {

	case 0:

		usbduxfast_ai_handle_urb(dev, s, urb);

		break;



		/*

		 * happens after an unlink command or when the device

		 * is plugged out

		 */

	case -ECONNRESET:

	case -ENOENT:

	case -ESHUTDOWN:

	case -ECONNABORTED:

		/* tell this comedi */

		async->events |= COMEDI_CB_EOA;

		/* after an unlink command, unplug, ... etc */

		async->events |= COMEDI_CB_ERROR;

		comedi_event(dev, s);

		/* stop the transfer w/o unlink */

		usbduxfast_ai_stop(dev, 0);

		return;

		break;



	default:

		/* a real error */

		dev_err(dev->class_dev,

			"non-zero urb status received in ai intr context: %d\n",

			urb->status);

		async->events |= COMEDI_CB_EOA;

		async->events |= COMEDI_CB_ERROR;

		comedi_event(dev, s);

		usbduxfast_ai_stop(dev, 0);

		return;

	}



	if (!devpriv->ignore) {

		if (cmd->stop_src == TRIG_COUNT) {

			/* not continuous, fixed number of samples */

			n = urb->actual_length / sizeof(uint16_t);

			if (unlikely(devpriv->ai_sample_count < n)) {

				unsigned int num_bytes;



				/* partial sample received */

				num_bytes = devpriv->ai_sample_count *

					    sizeof(uint16_t);

				cfc_write_array_to_buffer(s,

							  urb->transfer_buffer,

							  num_bytes);

				usbduxfast_ai_stop(dev, 0);

				/* tell comedi that the acquistion is over */

				async->events |= COMEDI_CB_EOA;

				comedi_event(dev, s);

				return;

			}

			devpriv->ai_sample_count -= n;

		}

		/* write the full buffer to comedi */

		err = cfc_write_array_to_buffer(s, urb->transfer_buffer,

						urb->actual_length);

		if (unlikely(err == 0)) {

			/* buffer overflow */

			usbduxfast_ai_stop(dev, 0);

			return;

		}



		/* tell comedi that data is there */

		comedi_event(dev, s);

	} else {

		/* ignore this packet */

		devpriv->ignore--;

		break;

	}



	/*

	 * command is still running

	 * resubmit urb for BULK transfer

	 * comedi_handle_events() cannot be used in this driver. The (*cancel)

	 * operation would unlink the urb.

	 */

	urb->dev = usb;

	urb->status = 0;

	err = usb_submit_urb(urb, GFP_ATOMIC);

	if (err < 0) {

		dev_err(dev->class_dev,

			"urb resubm failed: %d", err);

		async->events |= COMEDI_CB_EOA;

		async->events |= COMEDI_CB_ERROR;

		comedi_event(dev, s);

	if (async->events & COMEDI_CB_CANCEL_MASK)

		usbduxfast_ai_stop(dev, 0);

	}



	comedi_event(dev, s);

}



static int usbduxfast_submit_urb(struct comedi_device *dev)