Re: [PATCH v3 1/2] dt-bindings: drm/bridge: Add no-hpd property

[Dominik Haller]

Hi,


On Wed, 2025-02-05 at 17:20 +0530, Harikrishna Shenoy wrote:
> From: Rahul T R <r-ravikumar@xxxxxx>
> 
> The mhdp bridge can work without its HPD pin hooked up to the
> connector,
> but the current bridge driver throws an error when hpd line is not
> connected to the connector. For such cases, we need an indication for
> no-hpd, using which we can bypass the hpd detection and instead use
> the
> auxiliary channels connected to the DP connector to confirm the
> connection.
> So add no-hpd property to the bindings, to disable hpd when not
> connected or unusable due to DP0-HPD not connected to correct HPD 
> pin on SOC like in case of J721S2.
out of curiosity. This series doesn't have anything to do with the
other DP HPD pin (AA24 MCASP1_ACLKX.DP0_HPD in case of J721S2) still
being mandatory to mux?
> Signed-off-by: Rahul T R <r-ravikumar@xxxxxx>
> Signed-off-by: Jayesh Choudhary <j-choudhary@xxxxxx>
> ---
>  .../devicetree/bindings/display/bridge/cdns,mhdp8546.yaml   | 6
> ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git
> a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> index c2b369456e4e..3a6c6d837593 100644
> ---
> a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> +++
> b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8546.yaml
> @@ -57,6 +57,12 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  cdns,no-hpd:
> +    type: boolean
> +    description:
> +      Set if the HPD line on the bridge isn't hooked up to anything
> or is
> +      otherwise unusable.
> +
>    ports:
>      $ref: /schemas/graph.yaml#/properties/ports
>