Re: [PATCH v7 2/3] drm/msm/dpu: allow using two SSPP blocks for a single plane

[Abhinav Kumar]

On 12/11/2024 2:24 PM, Dmitry Baryshkov wrote:
> On Wed, Dec 11, 2024 at 01:51:51PM -0800, Abhinav Kumar wrote:
> > On 11/29/2024 5:55 PM, Dmitry Baryshkov wrote:
> > > Virtual wide planes give high amount of flexibility, but it is not
> > > always enough:
> > >
> > > In parallel multirect case only the half of the usual width is supported
> > > for tiled formats. Thus the whole width of two tiled multirect
> > > rectangles can not be greater than max_linewidth, which is not enough
> > > for some platforms/compositors.
> > >
> > > Another example is as simple as wide YUV plane. YUV planes can not use
> > > multirect, so currently they are limited to max_linewidth too.
> > >
> > > Now that the planes are fully virtualized, add support for allocating
> > > two SSPP blocks to drive a single DRM plane. This fixes both mentioned
> > > cases and allows all planes to go up to 2*max_linewidth (at the cost of
> > > making some of the planes unavailable to the user).
> >
> > Overall looks so much cleaner after unification!
> >
> > One small nit below,
> >
> >
> > You can still have,
> >
> > Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> >
> > Note: we have started testing this series with sc7180 CrOS, and will report
> > our findings/ give tested-by this week.
> >
> >
> > <snip>
> >
> > > +static bool dpu_plane_try_multirect_parallel(struct dpu_sw_pipe *pipe, struct dpu_sw_pipe_cfg *pipe_cfg,
> > > +					     struct dpu_sw_pipe *r_pipe, struct dpu_sw_pipe_cfg *r_pipe_cfg,
> > > +					     struct dpu_hw_sspp *sspp, const struct msm_format *fmt,
> > > +					     uint32_t max_linewidth)
> > > +{
> > > +	r_pipe->sspp = NULL;
> > > +
> > > +	pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> > > +	pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> > > +
> > > +	r_pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> > > +	r_pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> > > +
> >
> >
> > There are two places where the multirect_index and multirect_mode are reset.
> > Would it be better to just have a small api dpu_plane_reset_multirect() and
> > do this there?
>
> I'm not sure, what's the benefit. We can add an API to reset one pipe
> (to also be able to use it in _dpu_plane_atomic_disable()), but then
> it's just deduplication for the sake of deduplication.

Yeah I was thinking something like

dpu_plane_reset_multirect(pipe);
dpu_plane_reset_multirect(r_pipe);

But its only a minor benefit, hence as I wrote it as a nit. We can keep 
things as it is, if its unnecessary in your opinion.


>