Re: [PATCH v21 3/8] dt-bindings: display: bridge: Add Cadence MHDP8501

From: Krzysztof Kozlowski

Date: Wed Apr 08 2026 - 03:38:07 EST


On 08/04/2026 09:13, Laurentiu Palcu wrote:
>>> + phys:
>>> + maxItems: 1
>>> + description:
>>> + phandle to the DP/HDMI PHY
>>> +
>>> + interrupts:
>>> + items:
>>> + - description: Hotplug cable plugin.
>>> + - description: Hotplug cable plugout.
>>> +
>>> + interrupt-names:
>>> + items:
>>> + - const: plug_in
>>> + - const: plug_out
>>> +
>>> + cdns,bridge-type:
>>
>> Drop property. Graph defines what is connected on the other side. And if
>> this is for different devices then compatible tells what bridge is that.
>
> Initially, Sandor did use the remote compatible to decide the bridge
> type but he assumed the remote is always the connector. However, as
> Dmitry pointed out [1], this is not reliable as we can have another bridge
> in-between this one and the connector.
>
> [1] https://lore.kernel.org/all/dpj333mzr5azqhrgw3cxd7x5kiwxms4iomwy74uqfhr2zu4ocr@36rkth27d2jc/

So you still know what is on the other side, e.g. second bridge for HDMI
or DP, even if this is DP over USB-C.

I understand that Dmitry did not want to use that part of code in the
drivers, but what is located at the end is not really a separate
property of this bridge, because it already duplicates that information.
The final endpoint defines the type.


Best regards,
Krzysztof