Re: [PATCH] dt-bindings: display: panel: Make DSI panels port optional

[Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>]

On 11/11/2026 13:30, Krzysztof Kozlowski wrote:
> On 11/11/2026 12:13, Maxime Ripard wrote:
>> On Wed, Nov 11, 2026 at 12:03:39PM +0100, Krzysztof Kozlowski wrote:
>>> DSI panels can be placed under DSI bus directly and many Linux DRM
>>> drivers will work fine with it: mipi_dsi_host_register() adds device for
>>> such panel and DRM driver does not use OF graph to configure lanes.
>>
>> That's not true. We do use the endpoints to configure the lanes through
>> the data-lanes property. See drm_of_get_data_lanes*
> 
> Some drivers use endpoints, some not. As discussed on other thread,
> there are more than which do not.

"there are more than one which do not."

> 
>>
>>> The affected here Linux panel drivers do not use OF graph, either.
>>>
>>> Requiring graph port for such panels is tying the binding to one
>>> specific implementation of Linux DRM drivers, e.g. Qualcomm DRM which
>>> requires the port.  The port is not needed for the hardware to operate
>>> and for some of the Linux drivers, so it should be optional.
>>>
>>> Suggested-by: Romain TISSERAND <romain.tisserand@gmail.com>
>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
>>
>> DSI busses can handle multiple devices, and multiple data types. If we
>> were to drop the port node, how does the upstream video device know
>> which device it should send its video output to?
>>
> 
> We do not drop the port node, who suggested that?
> 
> You do get, that we are not talking about the DSI host, but the panel?

Best regards,
Krzysztof