drm: context_drm_egl: add support for enabling VRR

Variable Refresh Rate (VRR), aka Freesync or Adaptive Sync can be used
with DRM by setting the VRR_ENABLED property on a crtc if the
connector reports that it is VRR_CAPABLE. This is a useful feature
for us as it is common to play 24/25/50 fps content on displays that
are nominally locked to 60Hz. VRR can allow this content to play at
native framerates.

This is a simple change as we just need to check the capability
and set the enabled property if requested by the user. I've defaulted
it to disabled for now, but it might make sense to default to auto
in the long term.

1 files changed, 1 insertions, 0 deletions

diff --git a/video/out/drm_atomic.h b/video/out/drm_atomic.h
index 5b2dc5976d..32e56c7f97 100644
--- a/video/out/drm_atomic.h
+++ b/video/out/drm_atomic.h
@@ -56,6 +56,7 @@ struct drm_atomic_state {
     struct {
         struct drm_mode mode;
         uint64_t active;
+        uint64_t vrr_enabled;
     } crtc;
     struct drm_atomic_plane_state draw_plane;
     struct drm_atomic_plane_state drmprime_video_plane;