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From:   Shreeya Patel <shreeya.patel23498@gmail.com>
To:     lars@metafoo.de, Michael.Hennerich@analog.com, jic23@kernel.org,
        knaack.h@gmx.de, pmeerw@pmeerw.net, gregkh@linuxfoundation.org,
        linux-iio@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 2/7] Staging: iio: adt7316: Add an extra check for 'ret' equals to 0
Date:   Sat, 17 Nov 2018 04:21:32 +0530
Message-Id: <20181116225132.24459-1-shreeya.patel23498@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

ret = 0 indicates a case of no error but no data read from
the bus which is an invalid case. This case doesn't ever happen
in reality. It should perhaps be handled for correctness though.

Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com>
---
 drivers/staging/iio/addac/adt7316-i2c.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/staging/iio/addac/adt7316-i2c.c b/drivers/staging/iio/addac/adt7316-i2c.c
index 856bcfa60c6c..473e5e34ec00 100644
--- a/drivers/staging/iio/addac/adt7316-i2c.c
+++ b/drivers/staging/iio/addac/adt7316-i2c.c
@@ -30,6 +30,10 @@ static int adt7316_i2c_read(void *client, u8 reg, u8 *data)
 	}
 
 	ret = i2c_smbus_read_byte(client);
+
+	if (!ret)
+		return -EIO;
+
 	if (ret < 0) {
 		dev_err(&cl->dev, "I2C read error\n");
 		return ret;
-- 
2.17.1