On Fri, 2021-01-29 at 14:24 +0800, Hsin-Yi Wang wrote:
> On Fri, Jan 29, 2021 at 9:33 AM CK Hu <ck.hu@xxxxxxxxxxxx> wrote:
> >
> > Hi, Hsin-Yi:
> >
> > On Thu, 2021-01-28 at 19:23 +0800, Hsin-Yi Wang wrote:
> > > From: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> > >
> > > for 5 or 6 bpc panel, we need enable dither function
> > > to improve the display quality
> > >
> > > Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> > > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 15 +++++++++++++--
> > > 1 file changed, 13 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > index ac2cb25620357..6c8f246380a74 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > @@ -53,6 +53,7 @@
> > > #define DITHER_EN BIT(0)
> > > #define DISP_DITHER_CFG 0x0020
> > > #define DITHER_RELAY_MODE BIT(0)
> > > +#define DITHER_ENGINE_EN BIT(1)
> > > #define DISP_DITHER_SIZE 0x0030
> > >
> > > #define LUT_10BIT_MASK 0x03ff
> > > @@ -314,9 +315,19 @@ static void mtk_dither_config(struct device *dev, unsigned int w,
> > > unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
> > > {
> > > struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev);
> > > + bool enable = (bpc == 5 || bpc == 6);
> >
> > I strongly believe that dither function in dither is identical to the
> > one in gamma and od, and in mtk_dither_set_common(), 'bpc >=
> > MTK_MIN_BPC' is valid, so I believe we need not to limit bpc to 5 or 6.
> > But we should consider the case that bpc is invalid in
> > mtk_dither_set_common(). Invalid case in gamma and od use different way
> > to process. For gamma, dither is default relay mode, so invalid bpc
> > would do nothing in mtk_dither_set_common() and result in relay mode.
> > For od, it set to relay mode first, them invalid bpc would do nothing in
> > mtk_dither_set_common() and result in relay mode. I would like dither,
> > gamma and od to process invalid bpc in the same way. One solution is to
> > set relay mode in mtk_dither_set_common() for invalid bpc.
> >
> > Regards,
> > CK
> >
>
> I modify the mtk_dither_config() to follow:
>
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index ac2cb25620357..5b7fcedb9f9a8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -53,6 +53,7 @@
> #define DITHER_EN BIT(0)
> #define DISP_DITHER_CFG 0x0020
> #define DITHER_RELAY_MODE BIT(0)
> +#define DITHER_ENGINE_EN BIT(1)
> #define DISP_DITHER_SIZE 0x0030
>
> #define LUT_10BIT_MASK 0x03ff
> @@ -166,6 +167,8 @@ void mtk_dither_set_common(void __iomem *regs,
> struct cmdq_client_reg *cmdq_reg,
> DITHER_ADD_LSHIFT_G(MTK_MAX_BPC - bpc),
> cmdq_reg, regs, DISP_DITHER_16);
> mtk_ddp_write(cmdq_pkt, dither_en, cmdq_reg, regs, cfg);
> + } else {
> + mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, cmdq_reg, regs, cfg);
> }
> }
>
> @@ -315,8 +318,12 @@ static void mtk_dither_config(struct device *dev,
> unsigned int w,
> {
> struct mtk_ddp_comp_dev *priv = dev_get_drvdata(dev);
>
> - mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg,
> priv->regs, DISP_DITHER_SIZE);
> - mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg,
> priv->regs, DISP_DITHER_CFG);
> + mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg, priv->regs,
> + DISP_DITHER_SIZE);
> + mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg, priv->regs,
> + DISP_DITHER_CFG);
> + mtk_dither_set_common(priv->regs, &priv->cmdq_reg, bpc, DISP_DITHER_CFG,
> + DITHER_ENGINE_EN, cmdq_pkt);
> }
>
> So now, not only bpc==5 or 6, but all valid bpc, dither config will
> call mtk_dither_set_common() with the flag DITHER_ENGINE_EN(BIT(1)).
> od config will call mtk_dither_set_common() with the flag
> DISP_DITHERING(BIT(2)).
> Additionally for 8173, gamma config will call mtk_dither_set_common()
> with the flag DISP_DITHERING (BIT(2))
>
> For invalid mode all of them will be DITHER_RELAY_MODE.
>
> Just to make sure that this follows the spec? thanks
>
for mt8173 gamma, there is no relay mode, only dither enable or not(bit
2).
for mt8183 dither, there is dither enable bit 1, and relay mode bit 0
> > >
> > > - mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg, priv->regs, DISP_DITHER_SIZE);
> > > - mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg, priv->regs, DISP_DITHER_CFG);
> > > + if (enable) {
> > > + mtk_dither_set_common(priv->regs, &priv->cmdq_reg, bpc,
> > > + DISP_DITHER_CFG, DITHER_ENGINE_EN,
> > > + cmdq_pkt);
> > > + } else {
> > > + mtk_ddp_write(cmdq_pkt, DITHER_RELAY_MODE, &priv->cmdq_reg,
> > > + priv->regs, DISP_DITHER_CFG);
> > > + }
> > > +
> > > + mtk_ddp_write(cmdq_pkt, h << 16 | w, &priv->cmdq_reg, priv->regs,
> > > + DISP_DITHER_SIZE);
> > > }
> > >
> > > static void mtk_dither_start(struct device *dev)
> >
