staging: comedi: pass subdevice to comedi_buf_is_mmapped()

Change the parameters of `comedi_buf_is_mmapped()` to pass a pointer to
the comedi subdevice instead of a pointer to the "async" structure
belonging to the subdevice.

The main aim at the moment is to replace all the `struct comedi_async *`
parameters with `struct comedi_subdevice *` parameters in the comedi
driver API.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/comedi_buf.c

@@ -183,9 +183,9 @@ comedi_buf_map_from_subdev_get(struct comedi_subdevice *s)
 	return bm;
 }
 
-bool comedi_buf_is_mmapped(struct comedi_async *async)
+bool comedi_buf_is_mmapped(struct comedi_subdevice *s)
 {
-	struct comedi_buf_map *bm = async->buf_map;
+	struct comedi_buf_map *bm = s->async->buf_map;
 
 	return bm && (atomic_read(&bm->refcount.refcount) > 1);
 }

drivers/staging/comedi/comedi_fops.c

@@ -251,7 +251,7 @@ static int resize_async_buffer(struct comedi_device *dev,
 			"subdevice is busy, cannot resize buffer\n");
 		return -EBUSY;
 	}
-	if (comedi_buf_is_mmapped(async)) {
+	if (comedi_buf_is_mmapped(s)) {
 		dev_dbg(dev->class_dev,
 			"subdevice is mmapped, cannot resize buffer\n");
 		return -EBUSY;
@@ -635,7 +635,7 @@ static int is_device_busy(struct comedi_device *dev)
 		s = &dev->subdevices[i];
 		if (s->busy)
 			return 1;
-		if (s->async && comedi_buf_is_mmapped(s->async))
+		if (s->async && comedi_buf_is_mmapped(s))
 			return 1;
 	}
 

drivers/staging/comedi/comedi_internal.h

@@ -16,7 +16,7 @@ void comedi_free_subdevice_minor(struct comedi_subdevice *s);
 int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
 		     unsigned long new_size);
 void comedi_buf_reset(struct comedi_subdevice *s);
-bool comedi_buf_is_mmapped(struct comedi_async *async);
+bool comedi_buf_is_mmapped(struct comedi_subdevice *s);
 void comedi_buf_map_get(struct comedi_buf_map *bm);
 int comedi_buf_map_put(struct comedi_buf_map *bm);
 struct comedi_buf_map *comedi_buf_map_from_subdev_get(