From: Hector Martin <marcan@marcan.st>
To: Sasha Finkelstein <fnkl.kernel@gmail.com>, neil.armstrong@linaro.org
Cc: Sven Peter <sven@svenpeter.dev>,
Alyssa Rosenzweig <alyssa@rosenzweig.io>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Jessica Zhang <quic_jesszhan@quicinc.com>,
asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, Janne Grunau <j@jannau.net>
Subject: Re: [PATCH 2/5] gpu: drm: adp: Add Apple Display Pipe driver
Date: Mon, 25 Nov 2024 23:24:25 +0900 [thread overview]
Message-ID: <cc71021e-b53d-4eda-bad8-abb4df13575f@marcan.st> (raw)
In-Reply-To: <CAMT+MTRWZWj=3AP7wyooXr49-W4vcm0ZbAoqPyEuNkQBMOaJfw@mail.gmail.com>
On 2024/11/25 20:24, Sasha Finkelstein wrote:
> On Mon, 25 Nov 2024 at 09:50, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>
>> So this controller only supports a single mode ???????
>>
> Most likely. On all devices it is connected to a single built-in display.
More specifically, the controller obviously supports multiple modes but
it is pre-initialized by the bootloader for the single hardwired
display's only mode. So as far as the driver is concerned, there is a
single possible mode, and there's no point in trying to be more generic
if there is no hardware that would use that.
In general, it is not possible/practical to be generic for reverse
engineered hardware with no specs documenting how to drive it
generically. You just can't know how to implement the options that are
never used in practice. I spent a lot of time on exceptions to this rule
for the GPIO and SPI controllers, and that's not going to happen for
more complex hardware like MIPI DSI.
- Hector
next prev parent reply other threads:[~2024-11-25 14:24 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-24 22:29 [PATCH 0/5] Driver for pre-DCP apple display controller Sasha Finkelstein via B4 Relay
2024-11-24 22:29 ` [PATCH 1/5] dt-bindgins: display: Add Apple pre-DCP display controller bindings Sasha Finkelstein via B4 Relay
2024-11-25 2:06 ` Rob Herring (Arm)
2024-11-25 7:45 ` Krzysztof Kozlowski
2024-11-25 14:14 ` Hector Martin
2024-11-25 14:53 ` Krzysztof Kozlowski
2024-11-25 15:29 ` Hector Martin
2024-11-24 22:29 ` [PATCH 2/5] gpu: drm: adp: Add Apple Display Pipe driver Sasha Finkelstein via B4 Relay
2024-11-25 8:50 ` Neil Armstrong
2024-11-25 11:24 ` Sasha Finkelstein
2024-11-25 12:57 ` neil.armstrong
2024-11-25 13:14 ` Sasha Finkelstein
2024-11-25 13:16 ` neil.armstrong
2024-11-25 14:24 ` Hector Martin [this message]
2024-11-25 15:28 ` Maxime Ripard
2024-11-25 15:55 ` Hector Martin
2024-11-25 15:37 ` neil.armstrong
2024-11-25 9:04 ` Jani Nikula
2024-11-25 10:59 ` Alyssa Ross
2024-11-24 22:29 ` [PATCH 3/5] gpu: drm: adp: Add a backlight driver for the Summit LCD Sasha Finkelstein via B4 Relay
2024-11-25 8:45 ` Neil Armstrong
2024-11-25 11:28 ` Sasha Finkelstein
2024-11-25 14:49 ` Krzysztof Kozlowski
2024-11-25 15:03 ` Nick Chan
2024-11-25 15:06 ` Krzysztof Kozlowski
2024-11-26 16:34 ` Sasha Finkelstein
2024-11-26 16:52 ` Krzysztof Kozlowski
2024-11-24 22:29 ` [PATCH 4/5] arm64: dts: apple: Add touchbar screen nodes Sasha Finkelstein via B4 Relay
2024-11-25 8:39 ` Nick Chan
2024-11-25 8:43 ` Nick Chan
2024-11-24 22:29 ` [PATCH 5/5] MAINTAINERS: Add entries for touchbar display driver Sasha Finkelstein via B4 Relay
2024-11-25 9:24 ` Nick Chan
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