[Intel-gfx] [RFC] i915: Add fence fds to execbuffer2 uapi

[Chad Versace]

On Mon 27 Jun 2016, Chad Versace wrote:
> Let the hight 32 bits of drm_i915_gem_execbuffer2::rsvd1 contain an
> input and/or output fence fd, whose presence is controlled by flags.
> Also add I915_PARAM_HAS_FENCE_FD.
> 
> Signed-off-by: Chad Versace <chad.versace at intel.com>
> ---
>  include/uapi/drm/i915_drm.h | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)

Oops. git-send-email stripped the notes to the patch. Here's the notes:

This RFC proposes a uapi that integrates execbuf with Android sync fds.  Of
course, this is *only* an RFC because other devs are working on the i915
internals, and this patch depends on that work.

Why am I sending an RFC this early? I will soon begin prototyping Intel's
Mesa implementation of EGL_ANDROID_native_fence_sync, and that prototype will
be easier to write if I have a rough expectation of i915's eventual fence fd
uapi.

Please provide feedback: Does this roughly look like the uapi that the i915
devs expect?

(Pardon any stupidity in the patch. It's my first non-trivial kernel patch).