[PATCH 09/21] drm/msm/dpu: request more mixer for 4K+ DSC case

[Jun Nie]

Dmitry Baryshkov <dmitry.baryshkov at linaro.org> 于2024年8月29日周四 19:12写道：
>
> On Thu, 29 Aug 2024 at 13:20, Jun Nie <jun.nie at linaro.org> wrote:
> >
> > request more mixer for the case that hdisplay exceeding 4096
> > and DSC enabled.
>
> This doesn't seem to match the code. And it misses the _reason_ to do it.

Right. The DSC limitation should be 2560. And the reason is to support 4:4:2
quad-pipe topology. Because we prefer to use 4 layer mixer for dual DSI case.
The resolution is always higher and more DSC is power optimal. That's my
understanding.

> >
> > Signed-off-by: Jun Nie <jun.nie at linaro.org>
> > ---
> >  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 24 ++++++++++++++++++++----
> >  1 file changed, 20 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > index 05b203be2a9bc..33cfd94badaba 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > @@ -59,6 +59,7 @@
> >  #define IDLE_SHORT_TIMEOUT     1
> >
> >  #define MAX_HDISPLAY_SPLIT 1080
> > +#define MAX_HDISPLAY_DSC_SPLIT 2560
> >
> >  /* timeout in frames waiting for frame done */
> >  #define DPU_ENCODER_FRAME_DONE_TIMEOUT_FRAMES 5
> > @@ -588,15 +589,19 @@ static struct msm_display_topology dpu_encoder_get_topology(
> >
> >         /* Datapath topology selection
> >          *
> > -        * Dual display
> > +        * Dual display without DSC
> >          * 2 LM, 2 INTF ( Split display using 2 interfaces)
> >          *
> > +        * Dual display with DSC
> > +        * 4 LM, 2 INTF ( Split display using 2 interfaces)
>
> This doesn't match the code
>
Yeah, just use 4:4:2 case for DSC+dualDSI case is a simpler logic. I
can skip the DSC limitation
test in next version.