[RFC 0/2] New feature: Framebuffer processors

[Daniel Vetter]

On Thu, Aug 25, 2016 at 05:06:55PM +0900, Inki Dae wrote:
> 
> 
> 2016년 08월 24일 20:57에 Daniel Vetter 이(가) 쓴 글:
> > On Wed, Aug 24, 2016 at 08:44:24PM +0900, Inki Dae wrote:
> >> Hi,
> >>
> >> 2016년 08월 23일 18:41에 Daniel Stone 이(가) 쓴 글:
> >>> Hi,
> >>>
> >>> On 22 August 2016 at 16:23, Rob Clark <robdclark at gmail.com> wrote:
> >>>> I guess a lot comes down to 'how long before hw designers bolt a CP to
> >>>> the thing'..  at that point, I think you especially don't want a
> >>>> per-blit kernel interface.
> >>>
> >>> Regardless of whether or not we want it, we already _have_ it, in the
> >>> form of V4L2 M2M. There are already a few IP blocks working on that, I
> >>> believe. If V4L2 <-> KMS interop is painful, well, we need to fix that
> >>> anyway ...
> >>
> >> So we are trying this. We had expereneced using V4L2 and DRM together on
> >> Linux Platform makes it too complicated, and also integrated DRM with
> >> M2M such as 2D and Post processor makes it simplified.  So We have been
> >> trying to move existing V4L2 based drivers into DRM excepting HW Video
> >> Codec - called it MFC - and Camera sensor and relevant things.
> >> I think now V4L2 and DRM frameworks may make many engineers confusing
> >> because there are the same devices which can be controlled by V4L2 and
> >> DRM frameworks - maybe we would need more efforts like Laurent did with
> >> Live source[1] in the future.
> >
> > Can you pls explain in more detail where working with both v4l and drm
> > drivers and making them cooperate using dma-bufs poses problems? We should
> > definitely fix that.
> 
> I think it would be most Linux Platforms - Android, Chrome and Tizen -
> which would use OpenMAX/GStreammer for Multimedia and X or
> Wayland/SurfaceFlinger for Display.

Yes, that's the use case. Where is the problem in making this happen? v4l
can import dma-bufs, drm can export them, and there's plenty devices
shipping (afaik) that make use of exact this pipeline. Can you pls explain
what problem you've hit trying to make this work on exynos?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch