[PATCH] [media] v4l: mt9v032: Disable clock on error paths

From: Alexey Khoroshilov
Date: Fri Nov 24 2017 - 17:04:53 EST


mt9v032_power_on() leaves clk enabled in case of errors,
but it is not expected by its callers.
There is a similar problem in mt9v032_registered().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
drivers/media/i2c/mt9v032.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
index 8a430640c85d..4de63b2df334 100644
--- a/drivers/media/i2c/mt9v032.c
+++ b/drivers/media/i2c/mt9v032.c
@@ -294,14 +294,22 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
/* Reset the chip and stop data read out */
ret = regmap_write(map, MT9V032_RESET, 1);
if (ret < 0)
- return ret;
+ goto err;

ret = regmap_write(map, MT9V032_RESET, 0);
if (ret < 0)
- return ret;
+ goto err;
+
+ ret = regmap_write(map, MT9V032_CHIP_CONTROL,
+ MT9V032_CHIP_CONTROL_MASTER_MODE);
+ if (ret < 0)
+ goto err;
+
+ return 0;

- return regmap_write(map, MT9V032_CHIP_CONTROL,
- MT9V032_CHIP_CONTROL_MASTER_MODE);
+err:
+ clk_disable_unprepare(mt9v032->clk);
+ return ret;
}

static void mt9v032_power_off(struct mt9v032 *mt9v032)
@@ -876,6 +884,9 @@ static int mt9v032_registered(struct v4l2_subdev *subdev)

/* Read and check the sensor version */
ret = regmap_read(mt9v032->regmap, MT9V032_CHIP_VERSION, &version);
+
+ mt9v032_power_off(mt9v032);
+
if (ret < 0) {
dev_err(&client->dev, "Failed reading chip version\n");
return ret;
@@ -894,8 +905,6 @@ static int mt9v032_registered(struct v4l2_subdev *subdev)
return -ENODEV;
}

- mt9v032_power_off(mt9v032);
-
dev_info(&client->dev, "%s detected at address 0x%02x\n",
mt9v032->version->name, client->addr);

--
2.7.4