[PATCH v4 0/3] Add support of dmabuf in wayland/weston

[Jasper St. Pierre]

Sorry if this was discussed before, but any reason this is being put in
Wayland, and in the "wl_" namespace? DMA-BUF is a private Linux kernel
feature that's really semi-stable, not used by all drivers, and I'd hate
for it to bit-rot and tell people not to use it, the same way wl_shell
went. Having it only in the weston source tree, and in a private "dmabuf"
namespace seems like it should be enough for now.

On Tue, Jan 7, 2014 at 12:41 PM, <benjamin.gaignard at linaro.org> wrote:

> From: Benjamin Gaignard <benjamin.gaignard at linaro.org>
>
> The goal of this serie of patches is to add a way to use
> dmabuf file descriptor inside wayland and weston.
>
> In a context where there is no Mesa EGL (and so no wl_drm protocol)
> wl_dmabuf
> could be used as an alternative to shm to share buffers between hardware
> devices. If your hardware device (video decoder, renderer, etc...) need
> physical contiguous memory (obviously don't have MMU) wl_dmabuf may save
> the cost of one copy compare to shm.
>
> shm case:
> videodecoder --(copy into shm_buffer)--> weston(+pixman) --> HW renderer
>
> dmabuf case:
> videodecoder --(directly write in dmabuf buffer)--> weston(+pixman) --> HW
> renderer
>
> The server is responsible to send its supported pixel formats and the
> device
> name to be used by the client to allocate buffers.
>
> While mmap() call on dmabuf file descriptor result isn't guaranty on all
> architectures both server and client should take care of it before
> accessing
> to buffer data to avoid segfault.
>
> This series of patches include wayland and weston modifications.
> An example of how use wl_dmabuf is provided in
> weston/clients/simple-dmabuf.c
>
> === Wayland ===
> Benjamin Gaignard (1):
>   Add wl_dmabuf protocol
>
>  protocol/Makefile.am        |    6 +-
>  protocol/wayland-dmabuf.xml |  128 ++++++++++++++++++++++++
>  src/Makefile.am             |   12 ++-
>  src/wayland-dmabuf.c        |  231
> +++++++++++++++++++++++++++++++++++++++++++
>  src/wayland-dmabuf.h        |  123 +++++++++++++++++++++++
>  5 files changed, 496 insertions(+), 4 deletions(-)
>  create mode 100644 protocol/wayland-dmabuf.xml
>  create mode 100644 src/wayland-dmabuf.c
>  create mode 100644 src/wayland-dmabuf.h
>
> === Weston ===
> Benjamin Gaignard (2):
>   compositor-drm: allow to be a wl_dmabuf server
>   add simple-dmabuf client
>
>  clients/Makefile.am     |   11 ++
>  clients/simple-dmabuf.c |  469
> +++++++++++++++++++++++++++++++++++++++++++++++
>  configure.ac            |    5 +
>  src/compositor-drm.c    |   83 ++++++++-
>  src/compositor.c        |    4 +-
>  src/compositor.h        |    2 +
>  src/pixman-renderer.c   |   93 +++++++---
>  7 files changed, 637 insertions(+), 30 deletions(-)
>  create mode 100644 clients/simple-dmabuf.c
>
> --
> 1.7.9.5
>
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>



-- 
  Jasper
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