in the first version dither patch https://patchwork.kernel.org/project/linux-mediatek/patch/1553667561-25447-13-git-send-email-yongqiang.niu@xxxxxxxxxxxx/ dither 6 setting is included in that patch bit 1 is lfsr_en( "Enables LFSR-type dithering"), need enable bit 2 is rdither_en(Enables running order dithering), need disable in this issue https://partnerissuetracker.corp.google.com/issues/190643544 dither 6 setting missed in set dither common patch https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c?h=next-20210430&id=a6b7c98afdcad0f149010ae028b24f2d0dc24cdb Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx> --- drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c index 99cbf44..7dd8e05 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c @@ -26,6 +26,7 @@ #define DISP_OD_CFG 0x0020 #define DISP_OD_SIZE 0x0030 #define DISP_DITHER_5 0x0114 +#define DISP_DITHER_6 0x0118 #define DISP_DITHER_7 0x011c #define DISP_DITHER_15 0x013c #define DISP_DITHER_16 0x0140 @@ -135,6 +136,7 @@ void mtk_dither_set_common(void __iomem *regs, struct cmdq_client_reg *cmdq_reg, if (bpc >= MTK_MIN_BPC) { mtk_ddp_write(cmdq_pkt, 0, cmdq_reg, regs, DISP_DITHER_5); + mtk_ddp_write(cmdq_pkt, 0x3002, cmdq_reg, regs, DISP_DITHER_6); mtk_ddp_write(cmdq_pkt, 0, cmdq_reg, regs, DISP_DITHER_7); mtk_ddp_write(cmdq_pkt, DITHER_LSB_ERR_SHIFT_R(MTK_MAX_BPC - bpc) | -- 1.8.1.1.dirty