[PATCH 0/2] drm: rcar-du: Avoid writing reserved register fields

[Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>]

Hello,

This patch series addresses writes to reserved register fields or
reserved registers.

Depending on the DU variant, some registers or register fields are
marked as reserved, but the rcar-du driver writes them unconditionally.
There is a high chance that those registers and fields are simply
ignored, as shown by the lack of known issue. However, high chances
don't satisfy functional safety requirements when they don't match the
documentation.

As there is no chance of datasheet updates that will document these
reserved fields as safe to be written with non-zero values, update the
driver to comply with the documentation.

Laurent Pinchart (2):
  drm: rcar-du: Don't write unimplemented ESCR and OTAR registers on
    Gen3
  drm: rcar-du: Disable alpha blending for DU planes used with VSP

 drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 17 +++++++++++++++--
 drivers/gpu/drm/rcar-du/rcar_du_vsp.c  |  2 +-
 2 files changed, 16 insertions(+), 3 deletions(-)

-- 
Regards,

Laurent Pinchart