[RFC v1 0/4] drm: Add support for DRM_CAP_DEFERRED_OUT_FENCE capability

[Vivek Kasireddy]

By separating the OUT_FENCE signalling from pageflip completion allows
a Guest compositor to start a new repaint cycle with a new buffer
instead of waiting for the old buffer to be free. 

This work is based on the idea/suggestion from Simon and Pekka.

This capability can be a solution for this issue:
https://gitlab.freedesktop.org/wayland/weston/-/issues/514

Corresponding Weston MR:
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/668

Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: Pekka Paalanen <ppaalanen at gmail.com>
Cc: Simon Ser <contact at emersion.fr>
Cc: Michel Dänzer <michel at daenzer.net>
Cc: Tina Zhang <tina.zhang at intel.com>
Cc: Dongwon Kim <dongwon.kim at intel.com>

Vivek Kasireddy (4):
  drm: Add a capability flag to support deferred out_fence signalling
  virtio-gpu uapi: Add VIRTIO_GPU_F_OUT_FENCE feature
  drm/virtio: Add VIRTIO_GPU_CMD_RESOURCE_OUT_FENCE cmd
  drm/virtio: Probe and implement VIRTIO_GPU_F_OUT_FENCE feature

 drivers/gpu/drm/drm_file.c               | 11 +++---
 drivers/gpu/drm/drm_ioctl.c              |  3 ++
 drivers/gpu/drm/virtio/virtgpu_debugfs.c |  1 +
 drivers/gpu/drm/virtio/virtgpu_drv.c     |  1 +
 drivers/gpu/drm/virtio/virtgpu_drv.h     |  6 ++++
 drivers/gpu/drm/virtio/virtgpu_fence.c   |  9 +++++
 drivers/gpu/drm/virtio/virtgpu_kms.c     | 10 ++++--
 drivers/gpu/drm/virtio/virtgpu_plane.c   | 44 +++++++++++++++++++++++-
 drivers/gpu/drm/virtio/virtgpu_vq.c      | 17 +++++++++
 include/drm/drm_mode_config.h            |  9 +++++
 include/uapi/drm/drm.h                   |  1 +
 include/uapi/linux/virtio_gpu.h          | 12 +++++++
 12 files changed, 117 insertions(+), 7 deletions(-)

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2.30.2