Re: [PATCH 31/75] media: imx: capture: Support creating immutable link to capture device

[Steve Longerbeam <slongerbeam@xxxxxxxxx>]

Hi Laurent,

On 1/5/21 7:28 AM, Laurent Pinchart wrote:
> When the subdevice connected to the capture device has a single possible
> sink, there's no point in making the link mutable. Support creating
> immutable links.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
>   drivers/staging/media/imx/imx-ic-prpencvf.c   | 2 +-
>   drivers/staging/media/imx/imx-media-capture.c | 7 +++++--
>   drivers/staging/media/imx/imx-media-csi.c     | 2 +-
>   drivers/staging/media/imx/imx-media.h         | 3 ++-
>   drivers/staging/media/imx/imx7-media-csi.c    | 2 +-
>   5 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/staging/media/imx/imx-ic-prpencvf.c b/drivers/staging/media/imx/imx-ic-prpencvf.c
> index 88d69425e1b3..6c9c75ffb30c 100644
> --- a/drivers/staging/media/imx/imx-ic-prpencvf.c
> +++ b/drivers/staging/media/imx/imx-ic-prpencvf.c
> @@ -1269,7 +1269,7 @@ static int prp_registered(struct v4l2_subdev *sd)
>   	if (IS_ERR(priv->vdev))
>   		return PTR_ERR(priv->vdev);
>   
> -	ret = imx_media_capture_device_register(priv->vdev);
> +	ret = imx_media_capture_device_register(priv->vdev, false);

Might as well go ahead and pass true here now, to make the prpenc and 
prpvf links to the capture device immutable, since there is only one 
source and sink in this case.

Steve

>   	if (ret)
>   		goto remove_vdev;
>   
> diff --git a/drivers/staging/media/imx/imx-media-capture.c b/drivers/staging/media/imx/imx-media-capture.c
> index 04eb612ff1fa..c6991e8f151c 100644
> --- a/drivers/staging/media/imx/imx-media-capture.c
> +++ b/drivers/staging/media/imx/imx-media-capture.c
> @@ -898,12 +898,14 @@ static int capture_init_format(struct capture_priv *priv)
>   	return 0;
>   }
>   
> -int imx_media_capture_device_register(struct imx_media_video_dev *vdev)
> +int imx_media_capture_device_register(struct imx_media_video_dev *vdev,
> +				      bool immutable)
>   {
>   	struct capture_priv *priv = to_capture_priv(vdev);
>   	struct v4l2_subdev *sd = priv->src_sd;
>   	struct v4l2_device *v4l2_dev = sd->v4l2_dev;
>   	struct video_device *vfd = vdev->vfd;
> +	u32 flags;
>   	int ret;
>   
>   	/* get media device */
> @@ -927,8 +929,9 @@ int imx_media_capture_device_register(struct imx_media_video_dev *vdev)
>   		 video_device_node_name(vfd));
>   
>   	/* Create the link from the src_sd devnode pad to device node. */
> +	flags = immutable ? MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE : 0;
>   	ret = media_create_pad_link(&sd->entity, priv->src_sd_pad,
> -				    &vfd->entity, 0, 0);
> +				    &vfd->entity, 0, flags);
>   	if (ret) {
>   		dev_err(priv->dev, "failed to create link to device node\n");
>   		video_unregister_device(vfd);
> diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
> index 436f3d7160fa..d54d2a3789c0 100644
> --- a/drivers/staging/media/imx/imx-media-csi.c
> +++ b/drivers/staging/media/imx/imx-media-csi.c
> @@ -1796,7 +1796,7 @@ static int csi_registered(struct v4l2_subdev *sd)
>   		goto free_fim;
>   	}
>   
> -	ret = imx_media_capture_device_register(priv->vdev);
> +	ret = imx_media_capture_device_register(priv->vdev, false);
>   	if (ret)
>   		goto remove_vdev;
>   
> diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
> index 16ab879e0084..4efc4d186c0a 100644
> --- a/drivers/staging/media/imx/imx-media.h
> +++ b/drivers/staging/media/imx/imx-media.h
> @@ -288,7 +288,8 @@ struct imx_media_video_dev *
>   imx_media_capture_device_init(struct device *dev, struct v4l2_subdev *src_sd,
>   			      int pad, bool legacy_api);
>   void imx_media_capture_device_remove(struct imx_media_video_dev *vdev);
> -int imx_media_capture_device_register(struct imx_media_video_dev *vdev);
> +int imx_media_capture_device_register(struct imx_media_video_dev *vdev,
> +				      bool immutable);
>   void imx_media_capture_device_unregister(struct imx_media_video_dev *vdev);
>   struct imx_media_buffer *
>   imx_media_capture_device_next_buf(struct imx_media_video_dev *vdev);
> diff --git a/drivers/staging/media/imx/imx7-media-csi.c b/drivers/staging/media/imx/imx7-media-csi.c
> index afd1a7e35bfe..c087a212efdd 100644
> --- a/drivers/staging/media/imx/imx7-media-csi.c
> +++ b/drivers/staging/media/imx/imx7-media-csi.c
> @@ -1093,7 +1093,7 @@ static int imx7_csi_registered(struct v4l2_subdev *sd)
>   	if (IS_ERR(csi->vdev))
>   		return PTR_ERR(csi->vdev);
>   
> -	ret = imx_media_capture_device_register(csi->vdev);
> +	ret = imx_media_capture_device_register(csi->vdev, false);
>   	if (ret)
>   		imx_media_capture_device_remove(csi->vdev);
>