Re: [PATCH 04/11] media: adv7180: Use v4l2-ctrls core to handle s_ctrl locking

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Niklas,

On Thu, Jul 03, 2025 at 10:52:16PM +0200, Niklas Söderlund wrote:
> Instead of handling the state lock ourself in .s_ctrl use the v4l2-ctrls
> core to handle it for us. This will allow us later to use the unlocked
> __v4l2_ctrl_handler_setup() in initialization code where the state lock
> is already held.
> 
> Add a lockdep assert to demonstrate the mutex must be held when setting
> controls.
> 
> There is no functional change.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> ---
>  drivers/media/i2c/adv7180.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
> index bef708916190..c2a79eba4dcd 100644
> --- a/drivers/media/i2c/adv7180.c
> +++ b/drivers/media/i2c/adv7180.c
> @@ -601,11 +601,11 @@ static int adv7180_s_ctrl(struct v4l2_ctrl *ctrl)
>  {
>  	struct v4l2_subdev *sd = to_adv7180_sd(ctrl);
>  	struct adv7180_state *state = to_state(sd);
> -	int ret = mutex_lock_interruptible(&state->mutex);
> +	int ret = 0;
>  	int val;
>  
> -	if (ret)
> -		return ret;
> +	lockdep_assert_held(&state->mutex);
> +
>  	val = ctrl->val;
>  	switch (ctrl->id) {
>  	case V4L2_CID_BRIGHTNESS:
> @@ -647,7 +647,6 @@ static int adv7180_s_ctrl(struct v4l2_ctrl *ctrl)
>  		ret = -EINVAL;
>  	}
>  
> -	mutex_unlock(&state->mutex);
>  	return ret;
>  }
>  
> @@ -668,6 +667,7 @@ static const struct v4l2_ctrl_config adv7180_ctrl_fast_switch = {
>  static int adv7180_init_controls(struct adv7180_state *state)
>  {
>  	v4l2_ctrl_handler_init(&state->ctrl_hdl, 4);
> +	state->ctrl_hdl.lock = &state->mutex;
>  
>  	v4l2_ctrl_new_std(&state->ctrl_hdl, &adv7180_ctrl_ops,
>  			  V4L2_CID_BRIGHTNESS, ADV7180_BRI_MIN,

-- 
Regards,

Laurent Pinchart