staging: comedi: drivers (core): factor out async subdevice postconfig

Factor the setup of an async subdevice out of postconfig(). This allows
bringing the code back a couple indents and makes the postconfig a bit
clearer.

For aesthetic reasons, rename postconfig() to __comedi_device_postconfig().
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers.c

@@ -171,51 +171,32 @@ static int insn_rw_emulate_bits(struct comedi_device *dev,
 	return 1;
 }
 
-static int postconfig(struct comedi_device *dev)
+static int __comedi_device_postconfig_async(struct comedi_device *dev,
+					    struct comedi_subdevice *s)
 {
-	int i;
-	struct comedi_subdevice *s;
-	struct comedi_async *async = NULL;
-	int ret;
-
-	for (i = 0; i < dev->n_subdevices; i++) {
-		s = &dev->subdevices[i];
-
-		if (s->type == COMEDI_SUBD_UNUSED)
-			continue;
-
-		if (s->len_chanlist == 0)
-			s->len_chanlist = 1;
-
-		if (s->do_cmd) {
+	struct comedi_async *async;
 	unsigned int buf_size;
+	int ret;
 
-			BUG_ON((s->subdev_flags & (SDF_CMD_READ |
-						   SDF_CMD_WRITE)) == 0);
+	BUG_ON((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0);
 	BUG_ON(!s->do_cmdtest);
 
-			async =
-			    kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
-			if (async == NULL) {
-				dev_warn(dev->class_dev,
-					 "failed to allocate async struct\n");
+	async = kzalloc(sizeof(*async), GFP_KERNEL);
+	if (!async) {
+		dev_warn(dev->class_dev, "failed to allocate async struct\n");
 		return -ENOMEM;
 	}
 	init_waitqueue_head(&async->wait_head);
 	async->subdevice = s;
 	s->async = async;
 
-			async->max_bufsize =
-				comedi_default_buf_maxsize_kb * 1024;
+	async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
 	buf_size = comedi_default_buf_size_kb * 1024;
 	if (buf_size > async->max_bufsize)
 		buf_size = async->max_bufsize;
 
-			async->prealloc_buf = NULL;
-			async->prealloc_bufsz = 0;
 	if (comedi_buf_alloc(dev, s, buf_size) < 0) {
-				dev_warn(dev->class_dev,
-					 "Buffer allocation failed\n");
+		dev_warn(dev->class_dev, "Buffer allocation failed\n");
 		return -ENOMEM;
 	}
 	if (s->buf_change) {
@@ -223,7 +204,31 @@ static int postconfig(struct comedi_device *dev)
 		if (ret < 0)
 			return ret;
 	}
+
 	comedi_alloc_subdevice_minor(dev, s);
+
+	return 0;
+}
+
+static int __comedi_device_postconfig(struct comedi_device *dev)
+{
+	struct comedi_subdevice *s;
+	int ret;
+	int i;
+
+	for (i = 0; i < dev->n_subdevices; i++) {
+		s = &dev->subdevices[i];
+
+		if (s->type == COMEDI_SUBD_UNUSED)
+			continue;
+
+		if (s->len_chanlist == 0)
+			s->len_chanlist = 1;
+
+		if (s->do_cmd) {
+			ret = __comedi_device_postconfig_async(dev, s);
+			if (ret)
+				return ret;
 		}
 
 		if (!s->range_table && !s->range_table_list)
@@ -254,7 +259,7 @@ static int postconfig(struct comedi_device *dev)
 /* called with module refcount incremented, decrements it */
 static int comedi_device_postconfig(struct comedi_device *dev)
 {
-	int ret = postconfig(dev);
+	int ret = __comedi_device_postconfig(dev);
 	module_put(dev->driver->module);
 	if (ret < 0) {
 		__comedi_device_detach(dev);