Re: [PATCH v2 06/11] drm/msm/disp/dpu1: Don't use DSC with mode_3d

[Dmitry Baryshkov]

On 25/10/2021 19:10, Vinod Koul wrote:
> On 25-10-21, 17:40, Dmitry Baryshkov wrote:
> > On 20/10/2021 09:57, Vinod Koul wrote:
> > > On 14-10-21, 16:50, Dmitry Baryshkov wrote:
> > > > On 14/10/2021 16:41, Dmitry Baryshkov wrote:
> > > > > On 07/10/2021 10:08, Vinod Koul wrote:
>
> > > > > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > > > > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > > > > > index 806c171e5df2..5dfac5994bd4 100644
> > > > > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > > > > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > > > > > @@ -39,6 +39,7 @@ struct dpu_hw_stage_cfg {
> > > > > >      * @mode_3d:               3d mux configuration
> > > > > >      * @merge_3d:              3d merge block used
> > > > > >      * @intf_mode_sel:         Interface mode, cmd / vid
> > > > > > + * @dsc:                   DSC BIT masks
> > > > > >      * @stream_sel:            Stream selection for multi-stream interfaces
> > > > > >      */
> > > > > >     struct dpu_hw_intf_cfg {
> > > > > > @@ -46,6 +47,7 @@ struct dpu_hw_intf_cfg {
> > > > > >         enum dpu_3d_blend_mode mode_3d;
> > > > > >         enum dpu_merge_3d merge_3d;
> > > > > >         enum dpu_ctl_mode_sel intf_mode_sel;
> > > > > > +    unsigned int dsc;
> > > >
> > > > I think this should be:
> > > > enum dpu_dsc dsc[MAX_DSCS];
> > > > unsigned int num_dsc;
> > >
> > > hmmm, how do we go about getting the num_dsc value here.
> > > dpu_encoder_phys does not know about that..
> >
> > dpu_encoder_get_topology() can decide whether to use DSC or not and then set
> > num_dsc. For now it will always set 2 if we are using DSC at all, but let's
> > keep the decision in a single place rather than having it scattered all over
> > the driver.
>
> Yes agree, but dpu_encoder_get_topology() is private to encoder. Am not
> sure how best to propagate the info into the hw_intf_cfg?

Let dpu_encoder_get_topology() set num_dscs to 2 and merge_3d to 0 if 
the encoder has DSC information and to 0 otherwise. This will cover all 
topologies that we care about for now.

Regarding getting the DSC config. Currently you use single priv->dsc 
pointer, which works for the simple case of single DSI output, but will 
break as soon as somebody has DSC DSI + DP config. Either we can 
introduce the array of DSC configs, or we can add a DSI-specific 
msm_dsi_get_dsc_config(), which will be later paired with the 
corresponding displayport function.

--
With best wishes
Dmitry