Re: [PATCH v3 2/3] drm: bridge: add it66121 driver

From: Robert Foss <robert.foss@linaro.org>
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>
Subject: Re: [PATCH v3 2/3] drm: bridge: add it66121 driver
Date: Wed, 14 Apr 2021 10:06:37 +0200	[thread overview]
Message-ID: <CAG3jFysp+3__TfEyvKSf47q3nYsdRSbkb9LxX2pcJr356yAgKw@mail.gmail.com> (raw)
In-Reply-To: <3266977b-9d19-c81d-6fd7-b6fa0714b1ef@baylibre.com>

On Wed, 14 Apr 2021 at 08:13, Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> Hi Rob,
>
> Le 13/04/2021 à 22:21, Robert Foss a écrit :
> > Hey Neil & Phong,
> >
> > Thanks for submitting this series!
> >
> >> +
> >> +static const struct drm_bridge_funcs it66121_bridge_funcs = {
> >> +       .attach = it66121_bridge_attach,
> >> +       .enable = it66121_bridge_enable,
> >> +       .disable = it66121_bridge_disable,
> >> +       .mode_set = it66121_bridge_mode_set,
> >> +       .mode_valid = it66121_bridge_mode_valid,
> >> +       .detect = it66121_bridge_detect,
> >> +       .get_edid = it66121_bridge_get_edid,
> >> +       .atomic_get_output_bus_fmts = it66121_bridge_atomic_get_output_bus_fmts,
> >> +       .atomic_get_input_bus_fmts = 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_STATUS 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).