[PATCH v2] iio: pressure: hsc030pa: Improve i2c_transfer return value handling

[Antoniu Miclaus]

The i2c_transfer() function returns the number of messages
successfully transferred. The function sends 1 message but checks
for ret == 2, which can never be true.

In practice this has no impact since the caller checks ret < 0,
and the erroneous return value of 1 is not treated as an error.

Improve the return value handling to properly distinguish between
I2C errors and unexpected transfer counts.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
---
v2:
 - Changed subject from 'Fix' to 'Improve'
 - Clarified that the bug has no practical impact
 - Used explicit if/return pattern instead of ternary
 - Dropped Fixes tag

 drivers/iio/pressure/hsc030pa_i2c.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/pressure/hsc030pa_i2c.c b/drivers/iio/pressure/hsc030pa_i2c.c
index a34ef4653f34..3500bda03d75 100644
--- a/drivers/iio/pressure/hsc030pa_i2c.c
+++ b/drivers/iio/pressure/hsc030pa_i2c.c
@@ -34,8 +34,13 @@ static int hsc_i2c_recv(struct hsc_data *data)
 	msg.buf = data->buffer;
 
 	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0)
+		return ret;
 
-	return (ret == 2) ? 0 : ret;
+	if (ret != 1)
+		return -EIO;
+
+	return 0;
 }
 
 static int hsc_i2c_probe(struct i2c_client *client)
-- 
2.43.0