Re: [PATCH v2] firmware: qcom_scm: Only compile legacy calls on ARM

From: Stephen Boyd
Date: Thu Apr 08 2021 - 17:18:32 EST


Quoting Stephan Gerhold (2021-04-08 00:19:44)
> Personally, I think it would be best to introduce a new, SMC64 only
> compatible (e.g. "qcom,scm-64" like I mentioned). Then you can skip the
> detection check for the boards that opt-in by adding the compatible.
> You can then use it on all newer boards/SoCs/firmwares where you know
> exactly that there is SMC64.
>
> I would just like to avoid breaking any existing boards where we don't
> know exactly if they have SMC32 or SMC64.

Ok that's fair.

> >
> > Heh, it tried to ensure we use the right calling convention but broke
> > things in the process, because the way of detecting the convention isn't
> > always there. I wouldn't be surprised if this comes up again for other
> > boards that use TF-A.
>
> Ah okay, this sounds like a better reason than just trying to avoid the
> "overhead" of the detection step. :) I still think it should work if you
> just start marking all newer boards/SoCs/... as "qcom,scm-64" or
> something like that, right?

Sure. I can cook up a set of patches for this.