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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Tue, 9 Apr 2024 18:45:39 +0300
Message-ID: <CAA8EJpo68f=9ZyNnVY=+q+drHu9xJMSGk1kNCBa=HM442Jth8g@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] dt-bindings: display: mediatek: Add OF graph
 support for board path
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: chunkuang.hu@kernel.org, robh@kernel.org, 
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, 
	p.zabel@pengutronix.de, airlied@gmail.com, daniel@ffwll.ch, 
	maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, 
	matthias.bgg@gmail.com, shawn.sung@mediatek.com, yu-chang.lee@mediatek.com, 
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	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, 
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On Tue, 9 Apr 2024 at 18:41, AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>
> Il 09/04/24 17:20, Dmitry Baryshkov ha scritto:
> > On Tue, Apr 09, 2024 at 02:02:09PM +0200, AngeloGioacchino Del Regno wrote:
> >> The display IPs in MediaTek SoCs support being interconnected with
> >> different instances of DDP IPs (for example, merge0 or merge1) and/or
> >> with different DDP IPs (for example, rdma can be connected with either
> >> color, dpi, dsi, merge, etc), forming a full Display Data Path that
> >> ends with an actual display.
> >>
> >> The final display pipeline is effectively board specific, as it does
> >> depend on the display that is attached to it, and eventually on the
> >> sensors supported by the board (for example, Adaptive Ambient Light
> >> would need an Ambient Light Sensor, otherwise it's pointless!), other
> >> than the output type.
> >
> > With the color and gamma being in play, should the configuration be
> > board-driver or rather use-case driven with the driver being able to
> > reroute some of the blocks at runtime?
> >
>
> The driver can already set some blocks to "BYPASS MODE" at runtime, meaning
> that those will work as simple pass-through, performing *no* processing at
> all, so that's addressed from the very beginning.
>
> This doesn't mean that a specific pipeline must always support the "DISP_GAMMA"
> or the "DISP_CCOLOR" block(s) alone, or together, or in combination with another
> specific block.

I was thinking about slightly different case: do you have enough
colour blocks to drive all outputs or do you have to select them for
the particular output only?

(excuse me, I didn't check the platform details).

> For any other question, clarification, etc, I'm here :-)
>
> Cheers!
>
> >>
> >> Add support for OF graphs to most of the MediaTek DDP (display) bindings
> >> to add flexibility to build custom hardware paths, hence enabling board
> >> specific configuration of the display pipeline and allowing to finally
> >> migrate away from using hardcoded paths.
> >>
> >> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> >
>


-- 
With best wishes
Dmitry