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From:   Robert Foss <robert.foss@linaro.org>
Date:   Wed, 14 Apr 2021 10:06:37 +0200
Message-ID: <CAG3jFysp+3__TfEyvKSf47q3nYsdRSbkb9LxX2pcJr356yAgKw@mail.gmail.com>
Subject: Re: [PATCH v3 2/3] drm: bridge: add it66121 driver
To:     Neil Armstrong <narmstrong@baylibre.com>
Cc:     Andrzej Hajda <a.hajda@samsung.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        paul@crapouillou.net, Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Phong LE <ple@baylibre.com>
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On Wed, 14 Apr 2021 at 08:13, Neil Armstrong <narmstrong@baylibre.com> wrot=
e:
>
> Hi Rob,
>
> Le 13/04/2021 =C3=A0 22:21, Robert Foss a =C3=A9crit :
> > Hey Neil & Phong,
> >
> > Thanks for submitting this series!
> >
> >> +
> >> +static const struct drm_bridge_funcs it66121_bridge_funcs =3D {
> >> +       .attach =3D it66121_bridge_attach,
> >> +       .enable =3D it66121_bridge_enable,
> >> +       .disable =3D it66121_bridge_disable,
> >> +       .mode_set =3D it66121_bridge_mode_set,
> >> +       .mode_valid =3D it66121_bridge_mode_valid,
> >> +       .detect =3D it66121_bridge_detect,
> >> +       .get_edid =3D it66121_bridge_get_edid,
> >> +       .atomic_get_output_bus_fmts =3D it66121_bridge_atomic_get_outp=
ut_bus_fmts,
> >> +       .atomic_get_input_bus_fmts =3D it66121_bridge_atomic_get_input=
_bus_fmts,
> >> +};
> >
> > I would like to see an implementation of HPD, since it is supported by
> > the hardware[1] (and required by the documentation). IRQ status bit 0
> > seems to be the responsible for notifying us about hot plug detection
> > events.
>
> It's implemented in the IRQ handler with the IT66121_INT_STATUS1_HPD_STAT=
US event.
>

I didn't even get that far :)

Either way, the HPD support should be exposed in drm_bridge_funcs
(.hpd_enable, .hpd_disable (and possibly .hpd_notify)) and
drm_bridge.ops (DRM_BRIDGE_OP_HPD).