Having two or more channels with the same positive scan_index field
makes no sense. Prevent this situation by failing to register a buffer
if two scan indexes are identical.
Signed-off-by: Vlad Dogaru <vlad.dogaru@xxxxxxxxx>
---
Changes since v1:
- remove redundant check for scan_index < 0 in the inner loop.
drivers/iio/industrialio-buffer.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index f971f79..baf09c1 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -309,6 +309,27 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
return ret;
}
+static int iio_check_unique_scan_index(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *channels,
+ int num_channels)
+{
+ int i, j;
+
+ for (i = 0; i < num_channels - 1; i++) {
+ if (channels[i].scan_index < 0)
+ continue;
+ for (j = i + 1; j < num_channels; j++)
+ if (channels[i].scan_index == channels[j].scan_index) {
+ dev_err(&indio_dev->dev,
+ "duplicate scan index %d\n",
+ channels[i].scan_index);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static const char * const iio_scan_elements_group_name = "scan_elements";
int iio_buffer_register(struct iio_dev *indio_dev,
@@ -320,6 +341,10 @@ int iio_buffer_register(struct iio_dev *indio_dev,
struct iio_buffer *buffer = indio_dev->buffer;
int ret, i, attrn, attrcount, attrcount_orig = 0;
+ ret = iio_check_unique_scan_index(indio_dev, channels, num_channels);
+ if (ret < 0)
+ return ret;
+
if (buffer->attrs)
indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
--
1.9.1
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