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From:   Philip Chen <philipchen@chromium.org>
Date:   Wed, 27 Oct 2021 15:25:43 -0700
Message-ID: <CA+cxXhns12w=EiswKE-MgV2ehzPk6gBV-mL73GrvW0VirV011A@mail.gmail.com>
Subject: Re: [PATCH v4 2/2] drm/bridge: parade-ps8640: Populate devices on aux-bus
To:     Doug Anderson <dianders@chromium.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Robert Foss <robert.foss@linaro.org>,
        dri-devel <dri-devel@lists.freedesktop.org>
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Hi Doug

On Wed, Oct 27, 2021 at 3:13 PM Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Tue, Oct 26, 2021 at 2:56 PM Philip Chen <philipchen@chromium.org> wrote:
> >
> > Conventionally, panel is listed under the root of the device tree.
> > When userland asks for display mode, ps8640 bridge is responsible
> > for returning EDID when ps8640_bridge_get_edid() is called.
> >
> > Now enable a new option of listing panel under "aux-bus" of ps8640
> > bridge node in the device tree. In this case, panel driver can retrieve
> > EDID by triggering AUX transactions, without ps8640_bridge_get_edid()
> > calls at all.
> >
> > To prevent the "old" and "new" options from interfering with each
> > other's logic flow, disable DRM_BRIDGE_OP_EDID when the new option
> > is taken.
> >
> > Signed-off-by: Philip Chen <philipchen@chromium.org>
> > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> >
> > (no changes since v3)
> >
> > Changes in v3:
> > - Fix when to call of_node_put() in ps8640_of_panel_on_aux_bus()
> >
> > Changes in v2:
> > - Add of_node_put() calls in ps8640_of_panel_on_aux_bus()
> > - Select DRM_DP_AUX_BUS for PS8640 driver in Kconfig
> > - Replace _put_sync() with _put_sync_suspend() in ps8640_post_disable()
>
> Not that it terribly matters, but I don't think the "put_sync" vs.
> "put_sync_suspend" was in patch #2/2. It was in #1/2.
Oops, sorry, I did a terrible job separating the changes between patch
#1/2 and #2/2.
Will retroactively fix v2 change log when I post v5.

>
>
> >  drivers/gpu/drm/bridge/Kconfig         |  1 +
> >  drivers/gpu/drm/bridge/parade-ps8640.c | 51 ++++++++++++++++++++------
> >  2 files changed, 40 insertions(+), 12 deletions(-)
>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>