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    SubjectRe: [PATCH v2 7/7] arm64: dts: allwinner: a64: enable ANX6345 bridge on Teres-I
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    On 07.06.2019 11:40, Torsten Duwe wrote:
    > On Fri, Jun 07, 2019 at 08:28:02AM +0200, Maxime Ripard wrote:
    >> On Thu, Jun 06, 2019 at 03:59:27PM +0200, Harald Geyer wrote:
    >>> If think valid compatible properties would be:
    >>> compatible = "innolux,n116bge", "simple-panel";
    >>> compatible = "edp-connector", "simple-panel";
    >> A connector isn't a panel.
    >>
    >>> compatible = "innolux,n116bge", "edp-connector", "simple-panel";
    >> And the innolux,n116bge is certainly not a connector either.
    >>
    >>> compatible = "edp-connector", "innolux,n116bge", "simple-panel";
    >>>
    >>> I can't make up my mind which one I prefere. However neither of these
    >>> variants requires actually implmenting an edp-connector driver.
    >> No-one asked to do an edp-connector driver. You should use it in your
    >> DT, but if you want to have some code in your driver that parses the
    >> DT directly, I'm totally fine with that.
    > I must admit I fail to understand what that extra node would be good for.
    > Logically, the eDP far side is connected to the well-known n116bge.
    > Inside the laptop case it might as well be a flat ribbon cable or
    > soldered directly.
    > In good intention, that's all I wanted to express in the DT. I don't
    > know whether the relevant mechanical dimensions of the panel and the
    > connector are standardised, so whether one could in theory assemble it
    > with a different panel than the one it came with.
    >
    > OTOH, as I checked during the discussion with anarsoul, the panel's
    > supply voltage is permanently connected to the main 3.3V rail.
    > We already agreed that the eDP output port must not neccessarily be
    > specified, this setup is a good example why: because the panel is
    > always powered, the anx6345 can always pull valid EDID data from it
    > so at this stage there's no need for any OS driver to reach beyond
    > the bridge. IIRC even the backlight got switched off for the blank
    > screen without.
    >
    > All I wanted to say is that "there's usually an n116bge behind it";
    > but this is mostly redundant.
    >
    > So, shall we just drop the output port specification (along with the
    > panel node) in order to get one step further?


    I am not sure if I understand whole discussion here, but I also do not
    understand whole edp-connector thing.

    According to VESA[1] eDP is "Internal display interface" - there is no
    external connector for eDP, the way it is connected is integrator's
    decision, but it is fixed - ie end user do not plug/unplug it.

    If I remember correctly in some boards eDP is connected to some DP
    connector (odroid xu3 if I remember correctly), but this is non-standard
    hack, and for this case in bindings there should be rather dp-connector
    not edp-connector.

    [1]:
    https://www.vesa.org/wp-content/uploads/2010/12/DisplayPort-DevCon-Presentation-eDP-Dec-2010-v3.pdf


    Regards

    Andrzej


    >
    >> I guess you should describe why do you think it's "clear", because I'm
    >> not sure this is obvious for everyone here. eDP allows to discover
    >> which device is on the other side and its supported timings, just like
    >> HDMI for example (or regular DP, for that matter). Would you think
    >> it's clearly preferable to ship a DT with the DP/HDMI monitor
    >> connected on the other side exposed as a panel as well?
    > Well, as I wrote: "in good intention". That's the panel that comes with
    > the kit but it is very well detected automatically, just like you describe.
    >
    > So, just leave it out?
    >
    > Torsten
    >
    >
    >

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