[PATCH v6 03/13] iio: inkern: Check error explicitly in iio_channel_read_max()

[Herve Codina]

The current implementation returns the error code as part of the
default switch case.
This can lead to returning an incorrect positive value in case of
iio_avail_type enum entries evolution.

In order to avoid this case, be more strict in error checking.

Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
 drivers/iio/inkern.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 872fd5c24147..f738db9a0c04 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -858,6 +858,9 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		val2 = &unused;
 
 	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
+	if (ret < 0)
+		return ret;
+
 	switch (ret) {
 	case IIO_AVAIL_RANGE:
 		switch (*type) {
@@ -888,7 +891,7 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		return 0;
 
 	default:
-		return ret;
+		return -EINVAL;
 	}
 }
 
-- 
2.40.1