diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c
index f40d42298a117af2e263399c54aa881ef08d26b9..2feecf199f27c36f1804edff0231ddbeebc5a135 100644
--- a/drivers/staging/comedi/drivers/das16.c
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -762,8 +762,7 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s)
 		return -1;
 	}
 
-	devpriv->adc_byte_count =
-	    cmd->stop_arg * cmd->chanlist_len * sizeof(uint16_t);
+	devpriv->adc_byte_count = cmd->stop_arg * cfc_bytes_per_scan(s);
 
 	if (devpriv->can_burst)
 		outb(DAS1600_CONV_DISABLE, dev->iobase + DAS1600_CONV_REG);