[PATCH] media: i2c: imx296: Fix error handling while reading temperature

From: Christophe JAILLET
Date: Sun Apr 16 2023 - 18:14:52 EST


If imx296_read() returns an error, its returned value is a negative value.
But because of the "& IMX296_TMDOUT_MASK" (i.e. 0x3ff), 'tmdout' can't be
negative.

So the error handling does not work as expected and a wrong value is used
to compute the temperature.

Apply the IMX296_TMDOUT_MASK mask after checking for errors to fix it.

Fixes: cb33db2b6ccf ("media: i2c: IMX296 camera sensor driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/media/i2c/imx296.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/imx296.c b/drivers/media/i2c/imx296.c
index 4f22c0515ef8..c3d6d52fc772 100644
--- a/drivers/media/i2c/imx296.c
+++ b/drivers/media/i2c/imx296.c
@@ -922,10 +922,12 @@ static int imx296_read_temperature(struct imx296 *sensor, int *temp)
if (ret < 0)
return ret;

- tmdout = imx296_read(sensor, IMX296_TMDOUT) & IMX296_TMDOUT_MASK;
+ tmdout = imx296_read(sensor, IMX296_TMDOUT);
if (tmdout < 0)
return tmdout;

+ tmdout &= IMX296_TMDOUT_MASK;
+
/* T(°C) = 246.312 - 0.304 * TMDOUT */;
*temp = 246312 - 304 * tmdout;

--
2.34.1