Re: [RFC PATCH 9/9] media: vim2m: add request support

[Gustavo Padovan <gustavo@padovan.org>]

Hi Alex,

2017-12-15 Alexandre Courbot <acourbot@chromium.org>:

> Set the necessary ops for supporting requests in vim2m.
> 
> Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> ---
>  drivers/media/platform/vim2m.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
> index a32e8a7950eb..ffe94ef9214d 100644
> --- a/drivers/media/platform/vim2m.c
> +++ b/drivers/media/platform/vim2m.c
> @@ -30,6 +30,7 @@
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-event.h>
>  #include <media/videobuf2-vmalloc.h>
> +#include <media/media-request.h>
>  
>  MODULE_DESCRIPTION("Virtual device for mem2mem framework testing");
>  MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
> @@ -142,6 +143,7 @@ struct vim2m_dev {
>  	struct video_device	vfd;
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  	struct media_device	mdev;
> +	struct media_request_queue *req_queue;
>  #endif
>  
>  	atomic_t		num_inst;
> @@ -937,6 +939,11 @@ static int vim2m_open(struct file *file)
>  		goto open_unlock;
>  	}
>  
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +	v4l2_mem_ctx_request_init(ctx->fh.m2m_ctx, dev->req_queue,
> +				  &dev->vfd.entity);
> +#endif
> +
>  	v4l2_fh_add(&ctx->fh);
>  	atomic_inc(&dev->num_inst);
>  
> @@ -992,6 +999,12 @@ static const struct v4l2_m2m_ops m2m_ops = {
>  	.job_abort	= job_abort,
>  };
>  
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +static const struct media_entity_operations vim2m_entity_ops = {
> +	.process_request = v4l2_m2m_process_request,
> +};
> +#endif
> +
>  static int vim2m_probe(struct platform_device *pdev)
>  {
>  	struct vim2m_dev *dev;
> @@ -1006,6 +1019,10 @@ static int vim2m_probe(struct platform_device *pdev)
>  
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  	dev->mdev.dev = &pdev->dev;
> +	dev->req_queue = media_request_queue_generic_alloc(&dev->mdev);
> +	if (IS_ERR(dev->req_queue))
> +		return PTR_ERR(dev->req_queue);
> +	dev->mdev.req_queue = dev->req_queue;
>  	strlcpy(dev->mdev.model, "vim2m", sizeof(dev->mdev.model));
>  	media_device_init(&dev->mdev);
>  	dev->v4l2_dev.mdev = &dev->mdev;
> @@ -1023,6 +1040,11 @@ static int vim2m_probe(struct platform_device *pdev)
>  	vfd->lock = &dev->dev_mutex;
>  	vfd->v4l2_dev = &dev->v4l2_dev;
>  
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +	vfd->entity.ops = &vim2m_entity_ops;
> +	vfd->entity.req_ops = &media_entity_request_generic_ops;
> +#endif
> +

It seems to me that we can avoid most of this patch and just setup the
request support automatically when the media device node is registered.
The less change we impose to drivers the better I think.

Gustavo