[PATCH v2 02/17] media: rkisp1: capture: Fix and simplify (un)registration

[Jacopo Mondi]

Hi Laurent

On Fri, Mar 04, 2022 at 07:19:10PM +0200, Laurent Pinchart wrote:
> The rkisp1_register_capture() and rkisp1_unregister_capture() functions
> don't destroy the mutex (in the error path for the former). Fix this and
> make rkisp1_unregister_capture() and rkisp1_capture_devs_unregister()
> safe to be called on an unregistered capture node to prepare for
> simplification of error handling at probe time.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
>
> - Reset cap->rkisp1 in rkisp1_capture_devs_register()
> ---
>  .../platform/rockchip/rkisp1/rkisp1-capture.c | 26 ++++++++++---------
>  1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> index 9c11f2b8e5f5..96a7e6c0a622 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> @@ -1312,8 +1312,12 @@ static const struct v4l2_file_operations rkisp1_fops = {
>
>  static void rkisp1_unregister_capture(struct rkisp1_capture *cap)
>  {
> +	if (!cap->rkisp1)
> +		return;
> +
>  	media_entity_cleanup(&cap->vnode.vdev.entity);
>  	vb2_video_unregister_device(&cap->vnode.vdev);
> +	mutex_destroy(&cap->vnode.vlock);
>  }
>
>  void rkisp1_capture_devs_unregister(struct rkisp1_device *rkisp1)
> @@ -1390,6 +1394,7 @@ static int rkisp1_register_capture(struct rkisp1_capture *cap)
>
>  error:
>  	media_entity_cleanup(&vdev->entity);
> +	mutex_destroy(&node->vlock);
>  	return ret;
>  }
>
> @@ -1425,26 +1430,23 @@ rkisp1_capture_init(struct rkisp1_device *rkisp1, enum rkisp1_stream_id id)
>
>  int rkisp1_capture_devs_register(struct rkisp1_device *rkisp1)
>  {
> -	struct rkisp1_capture *cap;
> -	unsigned int i, j;
> +	unsigned int i;
>  	int ret;
>
>  	for (i = 0; i < ARRAY_SIZE(rkisp1->capture_devs); i++) {
> +		struct rkisp1_capture *cap = &rkisp1->capture_devs[i];
> +
>  		rkisp1_capture_init(rkisp1, i);
> -		cap = &rkisp1->capture_devs[i];
>  		cap->rkisp1 = rkisp1;

This is set by rkisp1_capture_init() already

> +
>  		ret = rkisp1_register_capture(cap);
> -		if (ret)
> -			goto err_unreg_capture_devs;
> +		if (ret) {
> +			cap->rkisp1 = NULL;

Is this correct ?

As:
> +			rkisp1_capture_devs_unregister(rkisp1);

Calls
rkisp1_capture_devs_unregister():
        rkisp1_unregister_capture():
                if (!cap->rkisp1)
                        return 0;

Effectively making rkisp1_capture_devs_unregister() a nop.

Thanks
   j

> +			return ret;
> +		}
>  	}
>
>  	return 0;
>
> -err_unreg_capture_devs:
> -	for (j = 0; j < i; j++) {
> -		cap = &rkisp1->capture_devs[j];
> -		rkisp1_unregister_capture(cap);
> -	}
> -
> -	return ret;
>  }
> --
> Regards,
>
> Laurent Pinchart
>