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