Re: [PATCH v1 2/6] arm: arm64: dts: Enable cros-ec-spi as wake source

[Rob Herring]

On Thu, Dec 14, 2023 at 3:04 PM Mark Hasemeyer <markhas@xxxxxxxxxxxx> wrote:
>
> > If a device knows it is wakeup capable, why do you need a property too?
>
> I'm referencing:
> https://www.kernel.org/doc/Documentation/devicetree/bindings/power/wakeup-source.txt
> "Nodes that describe devices which has wakeup capability must contain
> an "wakeup-source" boolean property."

That's probably too strongly worded because wakeup capable devices
existed (and still exist) before this binding was created. Powerpc for
example doesn't use it.

> Currently the driver assumes the device is wake capable without
> parsing the device tree, which is an incorrect assumption as wake
> capability should not be enabled on some cros_ec systems.
>
> > I haven't looked closely enough, but it smells like after patch 6, these
> > properties would be required for wakeup? That would be an ABI break.
>
> Agreed. In this case, the driver is a ChromeOS related driver and DTS
> is built from source for each OS update.
> For more context, I will make sure to CC you (and everyone else) and
> include a cover letter in the next series version.

Please explain in the patches with an ABI break why it doesn't matter.

Rob