Re: [PATCH] dt-bindings: display: bridge: lt9211: Require data-lanes on DSI input ports

[Marek Vasut]

On 4/7/26 10:00 AM, Krzysztof Kozlowski wrote:

> > NOTE: For example Linux kernel driver does already use that information
> >        and fails to probe if it is missing. There are currently no intree
>
> The first sentence must be part of the commit msg. That is important
> reason why you are doing this... but I don't see how you achieve any of
> this. Look:
>
>
> >        users for this binding, so no new warnings will be generated once
> >        this is applied, but a new user is about to be added.
>
> What warnings? How?

There are no in-tree users of this binding, so no DT checker warnings 
will be produced on existing in-tree DTs. I am in the process of adding 
a DTO which uses this binding now in arm64: dts: imx8mm: imx8mp: Add 
DTOs for Data Modul i.MX8M Mini and Plus eDM SBC

> > ---
> >   .../display/bridge/lontium,lt9211.yaml        | 37 ++++++++++++++++++-
> >   1 file changed, 35 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt9211.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt9211.yaml
> > index 9a6e9b25d14a9..5264fb2b68b78 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/lontium,lt9211.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt9211.yaml
> > @@ -36,18 +36,50 @@ properties:
> >   
> >       properties:
> >         port@0:
> > -        $ref: /schemas/graph.yaml#/properties/port
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
>
> OK, that's correct.
>
> > +        unevaluatedProperties: false
> >           description:
> >             Primary MIPI DSI port-1 for MIPI input or
> >             LVDS port-1 for LVDS input or DPI input.
> >   
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
>
> That's correct.
>
> > +
> > +            properties:
> > +              data-lanes:
> > +                description: array of physical DSI data lane indexes.
> > +                minItems: 1
> > +                items:
> > +                  - const: 1
> > +                  - const: 2
> > +                  - const: 3
> > +                  - const: 4
>
> That's almost redundant in this context - it was already there - and the
> point is that it solves noting in the problem you had. Binding still
> does not validate the ABI and does not match it, still.
>
> Since commit foo bar, driver needs data-lanes, so what you need to do is
> allow them and to require them. You can also specify their constraints
> if device can be configured multiple ways, up to 4 lanes.
Please pardon my ignorance, what exactly do you propose I change in this 
patch ?