Re: [PATCH] CHROMIUM: arm64: dts: qcom: Add sc7180-gelarshie

From: Doug Anderson <dianders@chromium.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: "Rob Herring" <robh@kernel.org>,
	"Julius Werner" <jwerner@chromium.org>,
	"Krzysztof Kozłowski" <k.kozlowski.k@gmail.com>,
	"Mars Chen" <chenxiangrui@huaqin.corp-partner.google.com>,
	"Andy Gross" <agross@kernel.org>,
	"Bjorn Andersson" <bjorn.andersson@linaro.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] CHROMIUM: arm64: dts: qcom: Add sc7180-gelarshie
Date: Thu, 12 May 2022 09:08:54 -0700	[thread overview]
Message-ID: <CAD=FV=XnsVEmPLKFjz4o-CTbvcVotOgrQ2NESkoFsYp1bO4d4g@mail.gmail.com> (raw)
In-Reply-To: <CAD=FV=VTNk_WPw+1sVRdToZLvDH_ve9QL+-+-unNEAK0k2hGMg@mail.gmail.com>

Hi,

On Wed, May 11, 2022 at 10:49 AM Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Wed, May 11, 2022 at 10:36 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org> wrote:
> >
> > > * If we want to change our scheme, we'd need to sit down and come to
> > > an agreement that satisfies everyone, if such a thing is possible.
> >
> > There is open CFP for ELCE 2022 (in Ireland). Maybe we could organize
> > some session there? But we for sure would need Rob, so the arrangements
> > should rather focus on him, not on my availability.
>
> Looks plausible to me to make it.
>
>
> > > I mean, to be fair I said it _seems_ pure overhead and then said that
> > > we could do it if it makes some tools happy. ...but before doing that,
> > > I wanted to make sure it was actually valuable. I still have doubts
> > > about the assertion that the most specific compatible is guaranteed to
> > > uniquely identify hardware. So if the whole reason for doing this is
> > > to make the validation tools happy and there's no other value, then at
> > > least it's plausible to argue that the tools could simply be fixed to
> > > allow this and not shout about it.
> >
> > Instead of adding bindings, you can indeed change/fix the tools. Go
> > ahead. :)
>
> I will try to take a quick look to see what this would look like.

I looked a bit and decided that unless maintainers agreed that we
should do this that it would just be a waste of time. I guess I'll
save it for the next time I see Rob...

> > > Since there no properties associated with the
> > > top-level compatible string, it's mostly just checking did some one
> > > copy-paste the compatible string from one file (the dts file) to the
> > > other file (the yaml file) correctly. To me, that does not feel like a
> > > useful check.
> >
> > Still it can detect messing of SoC compatibles or not defining any
> > board-level compatible thus pretending that someone's board is just
> > SC7180. Imagine now user-space or bootloader trying to parse it...
> >
> > BTW, the bindings validation of top-level compatible might actually help
> > you - to be sure that DTSes have proper compatibles matching what
> > bootloader expects.
>
> I'm still not seeing the help here. Is it somehow going to be easier
> for someone to sneak in a dts file to the kernel tree that is just
> "sc7180" than it will be to sneak an entry into the bindings that is
> just "sc7180"? The people reviewing the dts and the list of allowed
> boards in the bindings are the same people, right? Every entry in the
> bindings gets used to match exactly one board, so, as I said, it's
> pretty much just a question of whether you copy-pasted properly...

After a bit of time of copy pasting, we now have a 3-patch series that
starts with:

https://lore.kernel.org/r/20220512090429.1.I9804fcd5d6c8552ab25f598dd7a3ea71b15b55f0@changeid

-Doug