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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Thu, 25 Nov 2021 16:50:28 +0100
Message-ID: <CACRpkdZ4==HvMYrJe2jQMzeYqh65OKLEo9WEWDGZAZ8u7jkxFw@mail.gmail.com>
Subject: Re: [PATCH v3 3/4] arm64: dts: apple: t8103: Add i2c nodes
To:     Hector Martin <marcan@marcan.st>
Cc:     Janne Grunau <j@jannau.net>, Sven Peter <sven@svenpeter.dev>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Rob Herring <robh+dt@kernel.org>,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Wed, Nov 24, 2021 at 6:42 AM Hector Martin <marcan@marcan.st> wrote:

> Pulling down an I2C bus between transactions is not legal; the idle
> state has to be high.

Oh right.

> Apple are actually not very good at configuring GPIOs for power saving;
> e.g. the I/Os for that unused i2c bus still have their input buffers
> turned on, which is a waste of power. If they wanted to save the
> smallest drop of power they'd turn that off. But the effect of this is
> so trivial it probably makes no difference in the context of a laptop,
> nevermind a desktop like the Mac Mini.

Hm that's true. The saying is that 99% is the backlight, the remaining 1% isn't
so significant after that.

Yours,
Linus Walleij