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 <20230303143350.815623-6-treapking@chromium.org> <ZAXT0JFjERb8Q36f@smile.fi.intel.com>
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From:   Pin-yen Lin <treapking@chromium.org>
Date:   Wed, 8 Mar 2023 18:25:00 +0800
Message-ID: <CAEXTbpecGhEDrffDobb4NgLw8+vMK2_yVmJw8JGUDruTALm4-w@mail.gmail.com>
Subject: Re: [PATCH v13 05/10] drm/bridge: anx7625: Check for Type-C during
 panel registration
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Andrzej Hajda <andrzej.hajda@intel.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Robert Foss <rfoss@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
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        Daniel Vetter <daniel@ffwll.ch>,
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        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Daniel Scally <djrscally@gmail.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
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        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
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HI Andy,

On Mon, Mar 6, 2023 at 7:52=E2=80=AFPM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Mar 03, 2023 at 10:33:45PM +0800, Pin-yen Lin wrote:
> > The output port endpoints can be connected to USB-C connectors.
> > Running drm_of_find_panel_or_bridge() with such endpoints leads to
> > a continuous return value of -EPROBE_DEFER, even though there is
> > no panel present.
> >
> > To avoid this, check for the existence of a "mode-switch" property in
> > the port endpoint, and skip panel registration completely if so.
>
> ...
>
> > +     port_node =3D of_graph_get_port_by_id(np, 1);
> > +     count =3D typec_mode_switch_node_count(&port_node->fwnode);
>
> Do you need to drop reference count here?
> (I don't know myself, so, please check this)
>
> If no, patch LGTM.

The helper completes the for-loop of fwnode_for_each_child_node, which
drops the reference count whenever the next node is get. So we don't
need drop the reference count here.
>
> > +     if (count)
> > +             return 0;
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
Best regards,
Pin-yen