On 12/05/18 13:24, Sakari Ailus wrote:
> The Request API is now merged to the kernel but the confidence on the
> stability of that API is not great, especially regarding the interaction
> with V4L2.
>
> Add a Kconfig option for the API, with a scary-looking warning.
>
> The patch itself disables request creation as well as does not advertise
> them as buffer flags. The driver requiring requests (cedrus) now depends
> on the Kconfig option as well.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
> ---
> I hope this covers now everything... I was thinking how to make the option
> name itself more worrisome but I couldn't come up with a better language
> that would be compact enough. The "(EXPERIMENTAL)" notion is a bit too
> worn to be effective. :-I
>
> The patch can and should be reverted once we're entirely happy and
> confident with the API.
>
> drivers/media/Kconfig | 13 +++++++++++++
> drivers/media/common/videobuf2/videobuf2-v4l2.c | 2 ++
> drivers/media/media-device.c | 2 ++
> drivers/staging/media/sunxi/cedrus/Kconfig | 1 +
> 4 files changed, 18 insertions(+)
>
> diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig
> index 8add62a18293..102eb35fcf3f 100644
> --- a/drivers/media/Kconfig
> +++ b/drivers/media/Kconfig
> @@ -110,6 +110,19 @@ config MEDIA_CONTROLLER_DVB
>
> This is currently experimental.
>
> +config MEDIA_CONTROLLER_REQUEST_API
> + bool "Enable Media controller Request API (EXPERIMENTAL)"
> + depends on MEDIA_CONTROLLER && STAGING_MEDIA
> + default n
> + ---help---
> + DO NOT ENABLE THIS OPTION UNLESS YOU KNOW WHAT YOU'RE DOING.
> +
> + This option enables the Request API for the Media controller and V4L2
> + interfaces. It is currently needed by a few stateless codec drivers.
> +
> + There is currently no intention to provide API or ABI stability for
> + this new API as of yet.
> +
> #
> # Video4Linux support
> # Only enables if one of the V4L2 types (ATV, webcam, radio) is selected
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 1244c246d0c4..83c3c0c49e56 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -630,8 +630,10 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
> *caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;
> if (q->io_modes & VB2_DMABUF)
> *caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
> +#ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
> if (q->supports_requests)
> *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
> +#endif
> }
>
> int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index bed24372e61f..2ef114ce38d0 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -381,7 +381,9 @@ static long media_device_get_topology(struct media_device *mdev, void *arg)
> static long media_device_request_alloc(struct media_device *mdev,
> int *alloc_fd)
> {
> +#ifndef CONFIG_MEDIA_CONTROLLER_REQUEST_API
> if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
> +#endif
> return -ENOTTY;
>
> return media_request_alloc(mdev, alloc_fd);
> diff --git a/drivers/staging/media/sunxi/cedrus/Kconfig b/drivers/staging/media/sunxi/cedrus/Kconfig
> index a7a34e89c42d..3252efa422f9 100644
> --- a/drivers/staging/media/sunxi/cedrus/Kconfig
> +++ b/drivers/staging/media/sunxi/cedrus/Kconfig
> @@ -3,6 +3,7 @@ config VIDEO_SUNXI_CEDRUS
> depends on VIDEO_DEV && VIDEO_V4L2 && MEDIA_CONTROLLER
> depends on HAS_DMA
> depends on OF
> + depends on MEDIA_CONTROLLER_REQUEST_API
> select SUNXI_SRAM
> select VIDEOBUF2_DMA_CONTIG
> select V4L2_MEM2MEM_DEV
>
