media: ov2680: fix null dereference at power on

Swapping the order between v4l2 subdevice registration and checking chip
id in b7a41762 ("media: ov2680: don't register the v4l2 subdevice
before checking chip ID") makes the mode restore to use the sensor
controls before they are set, so move the mode restore call to s_power
after the handler setup for controls is done.

This remove also the need for the error code path in power on function.

Fixes: b7a41762 ("media: ov2680: don't register the v4l2 subdevice before checking chip ID")
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/i2c/ov2680.c

@@ -568,10 +568,6 @@ static int ov2680_power_on(struct ov2680_dev *sensor)
 	if (ret < 0)
 		return ret;
 
-	ret = ov2680_mode_restore(sensor);
-	if (ret < 0)
-		goto disable;
-
 	sensor->is_enabled = true;
 
 	/* Set clock lane into LP-11 state */
@@ -580,12 +576,6 @@ static int ov2680_power_on(struct ov2680_dev *sensor)
 	ov2680_stream_disable(sensor);
 
 	return 0;
-
-disable:
-	dev_err(dev, "failed to enable sensor: %d\n", ret);
-	ov2680_power_off(sensor);
-
-	return ret;
 }
 
 static int ov2680_s_power(struct v4l2_subdev *sd, int on)
@@ -606,6 +596,8 @@ static int ov2680_s_power(struct v4l2_subdev *sd, int on)
 		ret = v4l2_ctrl_handler_setup(&sensor->ctrls.handler);
 		if (ret < 0)
 			return ret;
+
+		ret = ov2680_mode_restore(sensor);
 	}
 
 	return ret;