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

From: Vinay Simha B N
Date: Thu Mar 19 2020 - 13:17:13 EST


On Thu, Mar 19, 2020 at 10:36 PM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> 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.
even after removing one bridge(dsi2hdmi) in the device tree, currently
using only one bridge(dsi2lvds), i do still get the compilation warning.

graph connection
to node '/soc/i2c@78b8000/bridge@f/ports/port@1/endpoint' is not
bidirectional

This compilation warning does not cause any problem with the boot image created
dsi -> dsi2lvds bridge-> lvds panel . Able to get the display properly.

https://github.com/vinaysimhabn/kernel-msm/blob/08e4821646b5c128559c506a5777d8782f1ff79e/Documentation/devicetree/bindings/display/bridge/toshiba%2Ctc358775.yaml

But while creating documentation yaml, it is not allowing to add this examples.
--
regards,
vinaysimha