DRM database property: OUT_FENCE_PTR

Back to index

Details

Name

OUT_FENCE_PTR

Flags

atomic

Type

range

Attached to

CRTC

Specification

[0, UINT64_MAX]

Documentation

Use this property to pass a file descriptor pointer to DRM. Once the
Atomic Commit request call returns OUT_FENCE_PTR will be filled with
the file descriptor number of a Sync File. This Sync File contains the
CRTC fence that will be signaled when all framebuffers present on the
Atomic Commit * request for that given CRTC are scanned out on the
screen.

The Atomic Commit request fails if a invalid pointer is passed. If the
Atomic Commit request fails for any other reason the out fence fd
returned will be -1. On a Atomic Commit with the
DRM_MODE_ATOMIC_TEST_ONLY flag the out fence will also be set to -1.

Note that out-fences don't have a special interface to drivers and are
internally represented by a &struct drm_pending_vblank_event in struct
&drm_crtc_state, which is also used by the nonblocking atomic commit
helpers and for the DRM event handling for existing userspace.

Driver support