[RFC PATCH v3 0/3] Support for Solid Fill Planes

[Jessica Zhang]

Introduce and add support for a solid_fill property. When the solid_fill
property is set, and the framebuffer is set to NULL, memory fetch will be
disabled.

In addition, loosen the NULL FB checks within the atomic commit callstack
to allow a NULL FB when the solid_fill property is set and add FB checks
in methods where the FB was previously assumed to be non-NULL.

Finally, have the DPU driver use drm_plane_state.solid_fill and instead of
dpu_plane_state.color_fill, and add extra checks in the DPU atomic commit
callstack to account for a NULL FB in cases where solid_fill is set.

Some drivers support hardware that have optimizations for solid fill
planes. This series aims to expose these capabilities to userspace as
some compositors have a solid fill flag (ex. SOLID_COLOR in the Android
hardware composer HAL) that can be set by apps like the Android Gears
app.

Userspace can set the solid_fill property to a blob containing the
appropriate version number and solid fill color (in RGB323232 format) and
setting the framebuffer to NULL.

Note: Currently, there's only one version of the solid_fill blob property.
However if other drivers want to support a similar feature, but require
more than just the solid fill color, they can extend this feature by
creating additional versions of the drm_solid_fill struct.

Changes in V2:
- Dropped SOLID_FILL_FORMAT property (Simon)
- Switched to implementing solid_fill property as a blob (Simon, Dmitry)
- Changed to checks for if solid_fill_blob is set (Dmitry)
- Abstracted (plane_state && !solid_fill_blob) checks to helper method
  (Dmitry)
- Removed DPU_PLANE_COLOR_FILL_FLAG
- Fixed whitespace and indentation issues (Dmitry)

Changes in V3:
- Fixed some logic errors in atomic checks (Dmitry)
- Introduced drm_plane_has_visible_data() and drm_atomic_check_fb() helper
  methods (Dmitry)

Jessica Zhang (3):
  drm: Introduce solid fill property for drm plane
  drm: Adjust atomic checks for solid fill color
  drm/msm/dpu: Use color_fill property for DPU planes

 drivers/gpu/drm/drm_atomic.c              | 136 +++++++++++++---------
 drivers/gpu/drm/drm_atomic_helper.c       |  34 +++---
 drivers/gpu/drm/drm_atomic_state_helper.c |   9 ++
 drivers/gpu/drm/drm_atomic_uapi.c         |  59 ++++++++++
 drivers/gpu/drm/drm_blend.c               |  17 +++
 drivers/gpu/drm/drm_plane.c               |   8 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c  |   9 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c |  65 +++++++----
 include/drm/drm_atomic_helper.h           |   5 +-
 include/drm/drm_blend.h                   |   1 +
 include/drm/drm_plane.h                   |  62 ++++++++++
 11 files changed, 302 insertions(+), 103 deletions(-)

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2.38.1