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Message-ID: <292c3e7d-82ea-2631-bd4b-ef747f56287c@linaro.org>
Date:   Thu, 3 Aug 2023 10:11:22 +0200
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From:   Neil Armstrong <neil.armstrong@linaro.org>
Reply-To: neil.armstrong@linaro.org
Content-Language: en-US
To:     Maxime Ripard <mripard@kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Michael Riesch <michael.riesch@wolfvision.net>,
        Sam Ravnborg <sam@ravnborg.org>,
        Sebastian Reichel <sre@kernel.org>,
        Gerald Loacker <gerald.loacker@wolfvision.net>
Cc:     David Airlie <airlied@gmail.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Conor Dooley <conor+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
References: <20230718-feature-lcd-panel-v1-0-e9a85d5374fd@wolfvision.net>
Organization: Linaro Developer Services
Subject: Re: [PATCH 0/4] drm/panel: sitronix-st7789v: add support for partial
 mode
In-Reply-To: <20230718-feature-lcd-panel-v1-0-e9a85d5374fd@wolfvision.net>
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Precedence: bulk

Hi,

On 18/07/2023 17:31, Michael Riesch wrote:
> Hi all,
> 
> This series adds support for the partial display mode to the Sitronix
> ST7789V panel driver. This is useful for panels that are partially
> occluded by design, such as the Jasonic JT240MHQS-HWT-EK-E3. Support
> for this particular panel is added as well.
> 
> Note: This series is already based on
> https://lore.kernel.org/lkml/20230714013756.1546769-1-sre@kernel.org/

I understand Maxime's arguments, but by looking closely at the code,
this doesn't look like an hack at all and uses capabilities of the
panel controller to expose a smaller area without depending on any
changes or hacks on the display controller side which is coherent.

Following's Daniel's summary we cannot compare it to TV overscan
because overscan is only on *some* displays, we can still get 100%
of the picture from the signal.
While here, we cannot, there's physically less pixels on the panel.

If there's no more still a strong nack or pending comments,
I plan to apply those tomorrow.

Thanks,
Neil

> 
> Looking forward to your comments!
> 
> ---
> Michael Riesch (4):
>        dt-bindings: vendor-prefixes: add jasonic
>        dt-bindings: display: st7789v: add jasonic jt240mhqs-hwt-ek-e3 display
>        drm/panel: sitronix-st7789v: add support for partial mode
>        drm/panel: sitronix-st7789v: add jasonic jt240mhqs-hwt-ek-e3 support
> 
>   .../bindings/display/panel/sitronix,st7789v.yaml   |  1 +
>   .../devicetree/bindings/vendor-prefixes.yaml       |  2 +
>   drivers/gpu/drm/panel/panel-sitronix-st7789v.c     | 67 +++++++++++++++++++++-
>   3 files changed, 68 insertions(+), 2 deletions(-)
> ---
> base-commit: b43dae411767f34288aa347f26b5ed2dade39469
> change-id: 20230718-feature-lcd-panel-26d9f29a7830
> 
> Best regards,