1 files changed, 28 insertions, 19 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 7462f1233974..84a952931f9f 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -942,13 +942,34 @@ int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
 }
 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
 
+static int iio_buffer_add_demux(struct iio_buffer *buffer,
+	struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
+	unsigned int length)
+{
+
+	if (*p && (*p)->from + (*p)->length == in_loc &&
+		(*p)->to + (*p)->length == out_loc) {
+		(*p)->length += length;
+	} else {
+		*p = kmalloc(sizeof(*p), GFP_KERNEL);
+		if (*p == NULL)
+			return -ENOMEM;
+		(*p)->from = in_loc;
+		(*p)->to = out_loc;
+		(*p)->length = length;
+		list_add_tail(&(*p)->l, &buffer->demux_list);
+	}
+
+	return 0;
+}
+
 static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 				   struct iio_buffer *buffer)
 {
 	const struct iio_chan_spec *ch;
 	int ret, in_ind = -1, out_ind, length;
 	unsigned in_loc = 0, out_loc = 0;
-	struct iio_demux_table *p;
+	struct iio_demux_table *p = NULL;
 
 	/* Clear out any old demux */
 	iio_buffer_demux_free(buffer);
@@ -981,11 +1002,6 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 			/* Make sure we are aligned */
 			in_loc = roundup(in_loc, length) + length;
 		}
-		p = kmalloc(sizeof(*p), GFP_KERNEL);
-		if (p == NULL) {
-			ret = -ENOMEM;
-			goto error_clear_mux_table;
-		}
 		ch = iio_find_channel_from_si(indio_dev, in_ind);
 		if (ch->scan_type.repeat > 1)
 			length = ch->scan_type.storagebits / 8 *
@@ -994,20 +1010,14 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 			length = ch->scan_type.storagebits / 8;
 		out_loc = roundup(out_loc, length);
 		in_loc = roundup(in_loc, length);
-		p->from = in_loc;
-		p->to = out_loc;
-		p->length = length;
-		list_add_tail(&p->l, &buffer->demux_list);
+		ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
+		if (ret)
+			goto error_clear_mux_table;
 		out_loc += length;
 		in_loc += length;
 	}
 	/* Relies on scan_timestamp being last */
 	if (buffer->scan_timestamp) {
-		p = kmalloc(sizeof(*p), GFP_KERNEL);
-		if (p == NULL) {
-			ret = -ENOMEM;
-			goto error_clear_mux_table;
-		}
 		ch = iio_find_channel_from_si(indio_dev,
 			indio_dev->scan_index_timestamp);
 		if (ch->scan_type.repeat > 1)
@@ -1017,10 +1027,9 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 			length = ch->scan_type.storagebits / 8;
 		out_loc = roundup(out_loc, length);
 		in_loc = roundup(in_loc, length);
-		p->from = in_loc;
-		p->to = out_loc;
-		p->length = length;
-		list_add_tail(&p->l, &buffer->demux_list);
+		ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
+		if (ret)
+			goto error_clear_mux_table;
 		out_loc += length;
 		in_loc += length;
 	}