Re: [PATCH v3 2/3] media: i2c: ov5647: Switch to using the sub-device state lock

From: Tarang Raval

Date: Wed Dec 31 2025 - 05:54:43 EST


Hi Xiaolei,

> Switch to using the sub-device state lock and properly call
> v4l2_subdev_init_finalize() / v4l2_subdev_cleanup() on probe() /
> remove().
> 
> Signed-off-by: Xiaolei Wang <xiaolei.wang@xxxxxxxxxxxxx>
> ---
>  drivers/media/i2c/ov5647.c | 37 ++++++++++++++++---------------------
>  1 file changed, 16 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
> index cbcb760ba5cd..bc81f378436a 100644
> --- a/drivers/media/i2c/ov5647.c
> +++ b/drivers/media/i2c/ov5647.c
> @@ -92,7 +92,6 @@ struct ov5647 {
>         struct v4l2_subdev              sd;
>         struct regmap                   *regmap;
>         struct media_pad                pad;
> -       struct mutex                    lock;
>         struct clk                      *xclk;
>         struct gpio_desc                *pwdn;
>         bool                            clock_ncont;
> @@ -807,10 +806,10 @@ __ov5647_get_pad_crop(struct ov5647 *ov5647,
>  static int ov5647_s_stream(struct v4l2_subdev *sd, int enable)
>  {
>         struct i2c_client *client = v4l2_get_subdevdata(sd);
> -       struct ov5647 *sensor = to_sensor(sd);
> +       struct v4l2_subdev_state *state;
>         int ret;
> 
> -       mutex_lock(&sensor->lock);
> +       state = v4l2_subdev_lock_and_get_active_state(sd);
> 
>         if (enable) {
>                 ret = pm_runtime_resume_and_get(&client->dev);
> @@ -831,14 +830,14 @@ static int ov5647_s_stream(struct v4l2_subdev *sd, int enable)
>                 pm_runtime_put(&client->dev);
>         }
> 
> -       mutex_unlock(&sensor->lock);
> +       v4l2_subdev_unlock_state(state);
> 
>         return 0;
> 
>  error_pm:
>         pm_runtime_put(&client->dev);
>  error_unlock:
> -       mutex_unlock(&sensor->lock);
> +       v4l2_subdev_unlock_state(state);
> 
>         return ret;
>  }
> @@ -886,7 +885,6 @@ static int ov5647_get_pad_fmt(struct v4l2_subdev *sd,
>         const struct v4l2_mbus_framefmt *sensor_format;
>         struct ov5647 *sensor = to_sensor(sd);
> 
> -       mutex_lock(&sensor->lock);
>         switch (format->which) {
>         case V4L2_SUBDEV_FORMAT_TRY:
>                 sensor_format = v4l2_subdev_state_get_format(sd_state,
> @@ -898,7 +896,6 @@ static int ov5647_get_pad_fmt(struct v4l2_subdev *sd,
>         }
> 
>         *fmt = *sensor_format;
> -       mutex_unlock(&sensor->lock);
> 
>         return 0;
>  }
> @@ -916,7 +913,6 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
>                                       fmt->width, fmt->height);
> 
>         /* Update the sensor mode and apply at it at streamon time. */
> -       mutex_lock(&sensor->lock);
>         if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
>                 *v4l2_subdev_state_get_format(sd_state, format->pad) = mode->format;
>         } else {
> @@ -945,7 +941,6 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
>                                          exposure_def);
>         }
>         *fmt = mode->format;
> -       mutex_unlock(&sensor->lock);
> 
>         return 0;
>  }
> @@ -958,10 +953,8 @@ static int ov5647_get_selection(struct v4l2_subdev *sd,
>         case V4L2_SEL_TGT_CROP: {
>                 struct ov5647 *sensor = to_sensor(sd);
> 
> -               mutex_lock(&sensor->lock);
>                 sel->r = *__ov5647_get_pad_crop(sensor, sd_state, sel->pad,
>                                                 sel->which);
> -               mutex_unlock(&sensor->lock);
> 
>                 return 0;
>         }
> @@ -1114,9 +1107,6 @@ static int ov5647_s_ctrl(struct v4l2_ctrl *ctrl)
>         struct i2c_client *client = v4l2_get_subdevdata(sd);
>         int ret = 0;
> 
> -
> -       /* v4l2_ctrl_lock() locks our own mutex */
> -
>         if (ctrl->id == V4L2_CID_VBLANK) {
>                 int exposure_max, exposure_def;
> 
> @@ -1316,13 +1306,11 @@ static int ov5647_probe(struct i2c_client *client)
>                 return -EINVAL;
>         }
> 
> -       mutex_init(&sensor->lock);
> -
>         sensor->mode = OV5647_DEFAULT_MODE;
> 
>         ret = ov5647_init_controls(sensor);
>         if (ret)
> -               goto mutex_destroy;
> +               return ret;
> 
>         sd = &sensor->sd;
>         v4l2_i2c_subdev_init(sd, client, &ov5647_subdev_ops);
> @@ -1350,9 +1338,16 @@ static int ov5647_probe(struct i2c_client *client)
>         if (ret < 0)
>                 goto power_off;
> 
> +       sd->state_lock = sensor->ctrls.lock;
> +       ret = v4l2_subdev_init_finalize(sd);
> +       if (ret < 0) {
> +               dev_err(&client->dev, "failed to init subdev: %d", ret);

Use dev_err_probe

> +               goto power_off;
> +       }
> +
>         ret = v4l2_async_register_subdev(sd);
>         if (ret < 0)
> -               goto power_off;
> +               goto v4l2_subdev_cleanup;
> 
>         /* Enable runtime PM and turn off the device */
>         pm_runtime_set_active(dev);
> @@ -1363,14 +1358,14 @@ static int ov5647_probe(struct i2c_client *client)
> 
>         return 0;
> 
> +v4l2_subdev_cleanup:
> +       v4l2_subdev_cleanup(sd);
>  power_off:
>         ov5647_power_off(dev);
>  entity_cleanup:
>         media_entity_cleanup(&sd->entity);
>  ctrl_handler_free:
>         v4l2_ctrl_handler_free(&sensor->ctrls);
> -mutex_destroy:
> -       mutex_destroy(&sensor->lock);
> 
>         return ret;
>  }
> @@ -1381,11 +1376,11 @@ static void ov5647_remove(struct i2c_client *client)
>         struct ov5647 *sensor = to_sensor(sd);
> 
>         v4l2_async_unregister_subdev(&sensor->sd);
> +       v4l2_subdev_cleanup(sd);
>         media_entity_cleanup(&sensor->sd.entity);
>         v4l2_ctrl_handler_free(&sensor->ctrls);
>         v4l2_device_unregister_subdev(sd);
>         pm_runtime_disable(&client->dev);
> -       mutex_destroy(&sensor->lock);
>  }
> 
>  static const struct dev_pm_ops ov5647_pm_ops = {
> --
> 2.43.0

Reviewed-by: Tarang Raval <tarang.raval@xxxxxxxxxxxxxxxxx>
                                                          
Best Regards,                                             
Tarang