Re: [PATCH v3 3/4] arm64: dts: apple: t8103: Add i2c nodes

From: Linus Walleij
Date: Thu Nov 25 2021 - 11:03:35 EST


On Wed, Nov 24, 2021 at 6:42 AM Hector Martin <marcan@xxxxxxxxx> 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