Re: [PATCH v17 1/4] dt-bindings: msm: disp: add yaml schemas for DPU bindings

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Fri 21 May 11:00 CDT 2021, Bjorn Andersson wrote:

> On Fri 21 May 05:27 CDT 2021, Krishna Manikandan wrote:
> > diff --git a/Documentation/devicetree/bindings/display/msm/dpu-sc7180.yaml b/Documentation/devicetree/bindings/display/msm/dpu-sc7180.yaml
> [..]
> > +      ports:
> > +        $ref: /schemas/graph.yaml#/properties/ports
> > +        description: |
> > +          Contains the list of output ports from DPU device. These ports
> > +          connect to interfaces that are external to the DPU hardware,
> > +          such as DSI, DP etc. Each output port contains an endpoint that
> > +          describes how it is connected to an external interface.
> > +
> > +        properties:
> > +          port@0:
> > +            $ref: /schemas/graph.yaml#/properties/port
> > +            description: DPU_INTF1 (DSI1)
> > +
> > +          port@2:
> > +            $ref: /schemas/graph.yaml#/properties/port
> > +            description: DPU_INTF0 (DP)
> 
> Why is port@0 INTF1 and why is port@2 INTF0? In the binding you're
> translating the two ports that are described are 0 and 1, representing
> INTF1 and INTF2, or DSI1 and DSI2, respectively.
> 
> Further more, I have a need for somehow describing the pairing of 4 DP
> INTFs (INTF 0, 3, 4 and 5) and how they are connected to the 3+1 DP+eDP
> controllers.
> 
> Downstream this seems to be handled by adding cell-index to the DP
> controllers and then matching that against the numbering in the driver's
> INTF array. But rather than adding cell-index to map this, can't we
> define that the port index is the INTF-number here?
> 
> 
> This would obviously break compatibility with existing DTBs, but we
> could start by doing it selectively for the new compatibles, fix up the
> existing dts files and then drop the selective application after 1 or 2
> LTS releases.
> 

In a chat with Rob I realized that my feedback here is unrelated to the
yaml conversion and any conclusions of this discussion should be a
separate patch anyways.

So with the two style issues below resolve you have my:

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

[..]
> > +examples:
[..]
> > +                   ports {
> > +                           #address-cells = <1>;
> > +                           #size-cells = <0>;
> > +
> > +                           port@0 {
> > +                                   reg = <0>;
> > +                                   dpu_intf1_out: endpoint {
> > +                                                  remote-endpoint = <&dsi0_in>;
> > +                                   };
> > +                           };
> > +
> > +                            port@2 {
> > +                                    reg = <2>;
> > +                                    dpu_intf0_out: endpoint {
> > +                                                   remote-endpoint = <&dp_in>;
> > +                                    };
> > +                            };
> 
> The indentation is inconsistent among the ports.
> 
> > +                   };
> > +         };
> > +    };
> > +...
> > diff --git a/Documentation/devicetree/bindings/display/msm/dpu-sdm845.yaml b/Documentation/devicetree/bindings/display/msm/dpu-sdm845.yaml
[..]
> > +      operating-points-v2: true
> 
> You have a blank line between all other properties, but not here.
> 
> > +      ports:

Regards,
Bjorn