Re: graph connection to node is not bidirectional kernel-5.6.0-rc6

From: Rob Herring
Date: Thu Mar 19 2020 - 13:06:31 EST


On Thu, Mar 19, 2020 at 9:56 AM Vinay Simha B N <simhavcs@xxxxxxxxx> wrote:
>
> On Thu, Mar 19, 2020 at 9:16 PM Rob Herring <robh@xxxxxxxxxx> wrote:
> >
> > On Thu, Mar 19, 2020 at 1:31 AM Vinay Simha B N <simhavcs@xxxxxxxxx> wrote:
> > >
> > > hi,
> > >
> > > I am getting the endpoint' is not bidirectional(d2l_in, dsi0_out)
> > > warning in compilation, built boot image works on qcom apq8016-ifc6309
> > > board with the dsi->bridge->lvds panel.
> > > Because of this warning i cannot create a .yaml documentation examples.
> > > Please suggest.
> > >
> > > tc_bridge: bridge@f {
> >
> > ^^^^^^^^
> >
> > > arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi:253.28-255.9: Warning
> > > (graph_endpoint): /soc/i2c@78b8000/bridge@39/ports/port@0/endpoint:
> >
> > ^^^^^^^^^
> >
> > Looks like you have 2 different bridges.
> >
> i had two bridges, if we disable one bridge also we get the warning
>
> arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi:333.53-335.35: Warning
> (graph_endpoint): /soc/auo,b101xtn01/port/endpoint: graph connection
> to node '/soc/i2c@78b8000/bridge@f/ports/port@1/endpoint' is not
> bidirectional

You can't just disable nodes. To switch which bridge is enabled, you
already have to modify remote-endpoint at the other end. So the
requirement is you have to modify both 'remote-endpoint' properties
(or really all 3).

The other options is if you want both connections described, then you
need 2 'endpoint' nodes to connect both bridges.