Document IN_FENCE_FD and OUT_FENCE_PTR properties. v2: incorporate comments from Daniel Vetter Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> [danvet: s/async/nonblocking/ atomic commits.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1479773488-15048-1-git-send-email-gustavo@padovan.org (cherry picked from commit 9a83a71ac0d57ceffa32cbbb438ded055ab77887) Signed-off-by: Marissa Wall <marissaw@google.com> Change-Id: I30f045523988648baf3d219a80c0438b2433822a