Re: [PATCH v4 2/3] media: i2c: ov9282: Switch to using the sub-device state lock

[Dave Stevenson]

On Thu, 5 Mar 2026 at 04:35, Xiaolei Wang <xiaolei.wang@xxxxxxxxxxxxx> wrote:
>
> 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>
> Reviewed-by: Tarang Raval <tarang.raval@xxxxxxxxxxxxxxxxx>

Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>

> ---
>  drivers/media/i2c/ov9282.c | 51 +++++++++++++++-----------------------
>  1 file changed, 20 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> index 56f854a4d04f..98e0a0732ef7 100644
> --- a/drivers/media/i2c/ov9282.c
> +++ b/drivers/media/i2c/ov9282.c
> @@ -221,7 +221,6 @@ struct ov9282 {
>         bool noncontinuous_clock;
>         const struct ov9282_mode *cur_mode;
>         u32 code;
> -       struct mutex mutex;
>  };
>
>  static const s64 link_freq[] = {
> @@ -795,8 +794,6 @@ static int ov9282_get_pad_format(struct v4l2_subdev *sd,
>  {
>         struct ov9282 *ov9282 = to_ov9282(sd);
>
> -       mutex_lock(&ov9282->mutex);
> -
>         if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
>                 struct v4l2_mbus_framefmt *framefmt;
>
> @@ -807,8 +804,6 @@ static int ov9282_get_pad_format(struct v4l2_subdev *sd,
>                                        fmt);
>         }
>
> -       mutex_unlock(&ov9282->mutex);
> -
>         return 0;
>  }
>
> @@ -829,8 +824,6 @@ static int ov9282_set_pad_format(struct v4l2_subdev *sd,
>         u32 code;
>         int ret = 0;
>
> -       mutex_lock(&ov9282->mutex);
> -
>         mode = v4l2_find_nearest_size(supported_modes,
>                                       ARRAY_SIZE(supported_modes),
>                                       width, height,
> @@ -856,8 +849,6 @@ static int ov9282_set_pad_format(struct v4l2_subdev *sd,
>                 }
>         }
>
> -       mutex_unlock(&ov9282->mutex);
> -
>         return ret;
>  }
>
> @@ -904,10 +895,8 @@ static int ov9282_get_selection(struct v4l2_subdev *sd,
>         case V4L2_SEL_TGT_CROP: {
>                 struct ov9282 *ov9282 = to_ov9282(sd);
>
> -               mutex_lock(&ov9282->mutex);
>                 sel->r = *__ov9282_get_pad_crop(ov9282, sd_state, sel->pad,
>                                                 sel->which);
> -               mutex_unlock(&ov9282->mutex);
>
>                 return 0;
>         }
> @@ -1019,9 +1008,10 @@ static int ov9282_stop_streaming(struct ov9282 *ov9282)
>  static int ov9282_set_stream(struct v4l2_subdev *sd, int enable)
>  {
>         struct ov9282 *ov9282 = to_ov9282(sd);
> +       struct v4l2_subdev_state *state;
>         int ret;
>
> -       mutex_lock(&ov9282->mutex);
> +       state = v4l2_subdev_lock_and_get_active_state(sd);
>
>         if (enable) {
>                 ret = pm_runtime_resume_and_get(ov9282->dev);
> @@ -1036,14 +1026,14 @@ static int ov9282_set_stream(struct v4l2_subdev *sd, int enable)
>                 pm_runtime_put(ov9282->dev);
>         }
>
> -       mutex_unlock(&ov9282->mutex);
> +       v4l2_subdev_unlock_state(state);
>
>         return 0;
>
>  error_power_off:
>         pm_runtime_put(ov9282->dev);
>  error_unlock:
> -       mutex_unlock(&ov9282->mutex);
> +       v4l2_subdev_unlock_state(state);
>
>         return ret;
>  }
> @@ -1285,9 +1275,6 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
>         if (ret)
>                 return ret;
>
> -       /* Serialize controls with sensor device */
> -       ctrl_hdlr->lock = &ov9282->mutex;
> -
>         /* Initialize exposure and gain */
>         lpfr = mode->vblank + mode->height;
>         ov9282->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> @@ -1409,13 +1396,10 @@ static int ov9282_probe(struct i2c_client *client)
>                 return dev_err_probe(ov9282->dev, PTR_ERR(ov9282->regmap),
>                                      "Failed to init CCI\n");
>
> -       mutex_init(&ov9282->mutex);
> -
>         ret = ov9282_power_on(ov9282->dev);
> -       if (ret) {
> -               dev_err(ov9282->dev, "failed to power-on the sensor");
> -               goto error_mutex_destroy;
> -       }
> +       if (ret)
> +               return dev_err_probe(ov9282->dev, ret,
> +                                    "failed to power-on the sensor");
>
>         /* Check module identity */
>         ret = ov9282_detect(ov9282);
> @@ -1448,27 +1432,34 @@ static int ov9282_probe(struct i2c_client *client)
>                 goto error_handler_free;
>         }
>
> -       ret = v4l2_async_register_subdev_sensor(&ov9282->sd);
> +       ov9282->sd.state_lock = ov9282->ctrl_handler.lock;
> +       ret = v4l2_subdev_init_finalize(&ov9282->sd);
>         if (ret < 0) {
> -               dev_err(ov9282->dev,
> -                       "failed to register async subdev: %d", ret);
> +               dev_err_probe(ov9282->dev, ret, "failed to init subdev\n");
>                 goto error_media_entity;
>         }
>
>         pm_runtime_set_active(ov9282->dev);
>         pm_runtime_enable(ov9282->dev);
> +
> +       ret = v4l2_async_register_subdev_sensor(&ov9282->sd);
> +       if (ret < 0)
> +               goto v4l2_subdev_cleanup;
> +
>         pm_runtime_idle(ov9282->dev);
>
>         return 0;
>
> +v4l2_subdev_cleanup:
> +       v4l2_subdev_cleanup(&ov9282->sd);
> +       pm_runtime_disable(ov9282->dev);
> +       pm_runtime_set_suspended(ov9282->dev);
>  error_media_entity:
>         media_entity_cleanup(&ov9282->sd.entity);
>  error_handler_free:
>         v4l2_ctrl_handler_free(ov9282->sd.ctrl_handler);
>  error_power_off:
>         ov9282_power_off(ov9282->dev);
> -error_mutex_destroy:
> -       mutex_destroy(&ov9282->mutex);
>
>         return ret;
>  }
> @@ -1482,9 +1473,9 @@ static int ov9282_probe(struct i2c_client *client)
>  static void ov9282_remove(struct i2c_client *client)
>  {
>         struct v4l2_subdev *sd = i2c_get_clientdata(client);
> -       struct ov9282 *ov9282 = to_ov9282(sd);
>
>         v4l2_async_unregister_subdev(sd);
> +       v4l2_subdev_cleanup(sd);
>         media_entity_cleanup(&sd->entity);
>         v4l2_ctrl_handler_free(sd->ctrl_handler);
>
> @@ -1492,8 +1483,6 @@ static void ov9282_remove(struct i2c_client *client)
>         if (!pm_runtime_status_suspended(&client->dev))
>                 ov9282_power_off(&client->dev);
>         pm_runtime_set_suspended(&client->dev);
> -
> -       mutex_destroy(&ov9282->mutex);
>  }
>
>  static const struct dev_pm_ops ov9282_pm_ops = {
> --
> 2.43.0
>