[PATCH 0/3] drm/vc4: Improve alpha format plane support

Stefan Schake stschake at gmail.com
Mon Mar 5 17:48:36 PST 2018

This series improves the handling of alpha formats with the VC4 HVS
compositor. Alpha formats are marked as premultiplied as is standard
for DRM. Further fix a display corruption issue when planes with
per-pixel alpha try blending from the (nonexistent) background by
selectively enabling a black background color fill.

This series follows the changes suggested by Eric Anholt in a previous
patch discussion:


A simple test program for the display corruption issue is available:


Stefan Schake (3):
  drm/vc4: Set premultiplied for alpha formats
  drm/vc4: Check if plane requires background fill
  drm/vc4: Enable background color fill when necessary

 drivers/gpu/drm/vc4/vc4_crtc.c  | 22 ++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_drv.h   |  6 ++++++
 drivers/gpu/drm/vc4/vc4_plane.c | 16 +++++++++++++++-
 drivers/gpu/drm/vc4/vc4_regs.h  |  1 +
 4 files changed, 44 insertions(+), 1 deletion(-)


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