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
> >
> > - 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)
>
