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From:   Robert Foss <robert.foss@linaro.org>
Date:   Tue, 8 Mar 2022 11:00:20 +0100
Message-ID: <CAG3jFyu47cv8oSecONM95KVoP=NOvgwafAp4TQ33CZ0Y4zWmnQ@mail.gmail.com>
Subject: Re: [PATCH v12 3/4] drm/bridge: anx7625: add MIPI DPI input feature
To:     Chen-Yu Tsai <wenst@chromium.org>
Cc:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= 
        <nfraprado@collabora.com>, Xin Ji <xji@analogixsemi.com>,
        a.hajda@samsung.com, narmstrong@baylibre.com,
        dan.carpenter@oracle.com, jonas@kwiboo.se,
        jernej.skrabec@gmail.com, airlied@linux.ie, daniel@ffwll.ch,
        sam@ravnborg.org, pihsun@chromium.org, tzungbi@google.com,
        maxime@cerno.tech, drinkcat@google.com, hsinyi@chromium.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        bliang@analogixsemi.com, qwen@analogixsemi.com, robh+dt@kernel.org,
        devicetree@vger.kernel.org
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On Mon, 7 Mar 2022 at 16:49, Robert Foss <robert.foss@linaro.org> wrote:
>
> On Mon, 7 Mar 2022 at 07:12, Chen-Yu Tsai <wenst@chromium.org> wrote:
> >
> > On Sun, Mar 06, 2022 at 07:13:30PM +0200, Laurent Pinchart wrote:
> > > Hello Xin,
> > >
> > > (Question for Rob below, and I'm afraid this is urgent as we need to
> > > merge a fix in v5.17).
> > >
> > > On Fri, Nov 05, 2021 at 11:19:03AM +0800, Xin Ji wrote:
> > > > The basic anx7625 driver only support MIPI DSI rx signal input.
> > > > This patch add MIPI DPI rx input configuration support, after apply
> > > > this patch, the driver can support DSI rx or DPI rx by adding
> > > > 'bus-type' in DT.
> > > >
> > > > Reviewed-by: Robert Foss <robert.foss@linaro.org>
> > > > Signed-off-by: Xin Ji <xji@analogixsemi.com>
> > > > ---
> > > >  drivers/gpu/drm/bridge/analogix/anx7625.c | 247 ++++++++++++++++------
> > > >  drivers/gpu/drm/bridge/analogix/anx7625.h |  18 +-
> > > >  2 files changed, 205 insertions(+), 60 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > > > index f48e91134c20..f7c3386c8929 100644
> > > > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> > > > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> >
> > [...]
> >
> > > >  static int anx7625_parse_dt(struct device *dev,
> > > >                         struct anx7625_platform_data *pdata)
> > > >  {
> > > > -   struct device_node *np = dev->of_node;
> > > > +   struct device_node *np = dev->of_node, *ep0;
> > > >     struct drm_panel *panel;
> > > >     int ret;
> > > > +   int bus_type, mipi_lanes;
> > > > +
> > > > +   anx7625_get_swing_setting(dev, pdata);
> > > >
> > > > +   pdata->is_dpi = 1; /* default dpi mode */
> > > >     pdata->mipi_host_node = of_graph_get_remote_node(np, 0, 0);
> > > >     if (!pdata->mipi_host_node) {
> > > >             DRM_DEV_ERROR(dev, "fail to get internal panel.\n");
> > > >             return -ENODEV;
> > > >     }
> > > >
> > > > -   DRM_DEV_DEBUG_DRIVER(dev, "found dsi host node.\n");
> > > > +   bus_type = V4L2_FWNODE_BUS_TYPE_PARALLEL;
> > > > +   mipi_lanes = MAX_LANES_SUPPORT;
> > > > +   ep0 = of_graph_get_endpoint_by_regs(np, 0, 0);
> > > > +   if (ep0) {
> > > > +           if (of_property_read_u32(ep0, "bus-type", &bus_type))
> > > > +                   bus_type = 0;
> > > > +
> > > > +           mipi_lanes = of_property_count_u32_elems(ep0, "data-lanes");
> > > > +   }
> > > > +
> > > > +   if (bus_type == V4L2_FWNODE_BUS_TYPE_PARALLEL) /* bus type is Parallel(DSI) */
> > >
> > > This is not correct *at all*. V4L2_FWNODE_BUS_TYPE_PARALLEL has nothing
> > > to do with DSI. DSI stands for Digital *Serial* Interface. If anything,
> > > the V4L2_FWNODE_BUS_TYPE_PARALLEL type would map better to DPI, even if
> > > it's not an exact match.
> > >
> > > This patch has landed in v5.17-rc1, along with the corresponding
> > > bindings. As DT bindings are an ABI, we should really fix this before
> > > v5.17 is released. There is no DSI bus types defined in DT, and adding
> > > one as a fix so late in the v5.17-rc cycle seems a bit of a stretch to
> > > me (unless Rob disagrees).
> > >
> > > It would seem best to revert this series and the corresponding bindings,
> > > and retry in v5.18.
> >
> > There is a DT patch using this property that is already queued up for 5.17
> > in the soc tree:
> >
> > https://lore.kernel.org/all/20220214200507.2500693-1-nfraprado@collabora.com/
> >
> > merged here:
> >
> > http://git.kernel.org/soc/soc/c/32568ae37596b529628ac09b875f4874e614f63f
> >
> > We will need to revert that one as well.
>
> I just submitted a series reverting the dt-binding change + the
> related commit to "mt8183: jacuzzi".
> Can I get a quick r-b/a-b in order to get this into v5.17.
>
> https://lore.kernel.org/all/20220307154558.2505734-3-robert.foss@linaro.org/
>

v2 of revert submitted.

https://lore.kernel.org/all/20220308094911.2680291-1-robert.foss@linaro.org/

Xin: Will you spin a series that adds DPI support and re-enables DPI
for anx7625? Additionally, "mt8183: jacuzzi" will have to have DPI
re-enabled.