Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <CAGWqDJ7AccvoxjKfQJ3GytJ-+u56Bk3rEn0sSYv-zCuBe1brAg@mail.gmail.com>
 <CAL_JsqLz-0myc-PSSaCQWDFXQx+=X9nBSXWsJaGCVqTFn0d5kw@mail.gmail.com> <CAGWqDJ4yA4ikz5MwQQwW8CAvE_dt16iuvN6cKRL2DdAuw8QWww@mail.gmail.com>
In-Reply-To: <CAGWqDJ4yA4ikz5MwQQwW8CAvE_dt16iuvN6cKRL2DdAuw8QWww@mail.gmail.com>
From:   Rob Herring <robh@kernel.org>
Date:   Thu, 19 Mar 2020 11:06:15 -0600
Message-ID: <CAL_JsqLU4kEmRnXhQ5+gP-ZisS2Za+s6mNFg4RnMdpDtDRQB3g@mail.gmail.com>
Subject: Re: graph connection to node is not bidirectional kernel-5.6.0-rc6
To:     Vinay Simha B N <simhavcs@gmail.com>
Cc:     "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <freedreno@lists.freedesktop.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Mar 19, 2020 at 9:56 AM Vinay Simha B N <simhavcs@gmail.com> wrote:
>
> On Thu, Mar 19, 2020 at 9:16 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Thu, Mar 19, 2020 at 1:31 AM Vinay Simha B N <simhavcs@gmail.com> 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.