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*

> 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?

Maxime