staging: comedi: usbdux: use comedi_async 'scans_done' to detect AO EOA

Remove the private data member 'ao_sample_count' and use the comedi_async
'scans_done' member to detect the analog output end-of-acquisition.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/usbdux.c

@@ -204,7 +204,6 @@ struct usbdux_private {
 
 	/* number of samples to acquire */
 	int ai_sample_count;
-	int ao_sample_count;
 	/* time between samples in units of the timer */
 	unsigned int ai_timer;
 	unsigned int ao_timer;
@@ -397,12 +396,10 @@ static void usbduxsub_ao_handle_urb(struct comedi_device *dev,
 	if (devpriv->ao_counter == 0) {
 		devpriv->ao_counter = devpriv->ao_timer;
 
-		if (cmd->stop_src == TRIG_COUNT) {
-			devpriv->ao_sample_count--;
-			if (devpriv->ao_sample_count < 0) {
-				async->events |= COMEDI_CB_EOA;
-				return;
-			}
+		if (cmd->stop_src == TRIG_COUNT &&
+		    async->scans_done >= cmd->stop_arg) {
+			async->events |= COMEDI_CB_EOA;
+			return;
 		}
 
 		/* transmit data to the USB bus */
@@ -1011,24 +1008,6 @@ static int usbdux_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	devpriv->ao_counter = devpriv->ao_timer;
 
-	if (cmd->stop_src == TRIG_COUNT) {
-		/* not continuous */
-		/* counter */
-		/* high speed also scans everything at once */
-		if (0) {	/* (devpriv->high_speed) */
-			devpriv->ao_sample_count = cmd->stop_arg *
-						   cmd->scan_end_arg;
-		} else {
-			/* there's no scan as the scan has been */
-			/* perf inside the FX2 */
-			/* data arrives as one packet */
-			devpriv->ao_sample_count = cmd->stop_arg;
-		}
-	} else {
-		/* continous acquisition */
-		devpriv->ao_sample_count = 0;
-	}
-
 	if (cmd->start_src == TRIG_NOW) {
 		/* enable this acquisition operation */
 		devpriv->ao_cmd_running = 1;