[PATCH v2] media: i2c: imx471: Fix uninitialized error value in imx471_set_ctrl()

[David Carlier <devnexen@gmail.com>]

The exposure and vertical blanking writes pass the address of the local
ret variable to cci_write() as its error pointer, but there is no earlier
error to propagate: each case is a single standalone write, like the other
controls in the same switch that already pass NULL. In the exposure case
ret is still uninitialized, so a non-zero stack value makes cci_write()
return early without programming the register, and the control write
reports a bogus status. The vertical blanking case is benign today because
ret is zero there, but the construct is equally wrong.

Pass NULL as the error pointer in both cases.

Fixes: be1589e567ae ("media: i2c: imx471: Add Sony IMX471 image sensor driver")
Suggested-by: Kate Hsuan <hpa@redhat.com>
Signed-off-by: David Carlier <devnexen@gmail.com>
---
Changes in v2:
- Fix the root cause by passing NULL as the cci_write() error pointer for
  the exposure and vertical blanking writes, instead of initializing ret
  to zero (Kate Hsuan).

v1: https://lore.kernel.org/linux-media/20260724041417.9921-1-devnexen@gmail.com/

 drivers/media/i2c/imx471.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/imx471.c b/drivers/media/i2c/imx471.c
index 6d358b11e96d..4053aed84340 100644
--- a/drivers/media/i2c/imx471.c
+++ b/drivers/media/i2c/imx471.c
@@ -334,12 +334,12 @@ static int imx471_set_ctrl(struct v4l2_ctrl *ctrl)
 		break;
 	case V4L2_CID_EXPOSURE:
 		ret = cci_write(sensor->regmap, IMX471_REG_EXPOSURE,
-				ctrl->val, &ret);
+				ctrl->val, NULL);
 		break;
 	case V4L2_CID_VBLANK:
 		/* Update FLL that meets expected vertical blanking */
 		ret = cci_write(sensor->regmap, IMX471_REG_FLL,
-				format->height + ctrl->val, &ret);
+				format->height + ctrl->val, NULL);
 		break;
 	case V4L2_CID_TEST_PATTERN:
 		ret = cci_write(sensor->regmap, IMX471_REG_TEST_PATTERN,
-- 
2.53.0