Re: [PATCH v3] kbuild: Enable DT schema checks for %.dtb targets

[Rob Herring <robh@kernel.org>]

On Sat, Jul 16, 2022 at 05:12:38PM +0900, Masahiro Yamada wrote:
> On Sat, Jul 16, 2022 at 8:02 AM Rob Herring <robh@kernel.org> wrote:
> >
> > On Thu, Jun 23, 2022 at 8:44 AM Dmitry Baryshkov
> > <dmitry.baryshkov@linaro.org> wrote:
> > >
> > > It is possible to build a single dtb, but not with DT schema validation
> > > enabled. Enable the schema validation to run for %.dtb and %.dtbo
> > > targets. Anyone building a dtb for a specific platform *should* pay
> > > attention to schema warnings.
> > >
> > > This could be supported with a separate %.dt.yaml target instead.
> > > However, the .dt.yaml format is considered an intermediate format and
> > > could possibly go away at some point if schema checking is integrated
> > > into dtc. Also, the plan is to enable the schema checks by default once
> > > platforms are free of warnings, and this is a move in that direction.
> > >
> > > This patch differs from the previous one ([1]) in the fact that it
> > > requires specifying VALIDATE_DT=1 to run the checks while doing the
> > > build. Thus default build procedures would not obtain additional build
> > > dependency, while maintainers can still build a single DTB file an get
> > > only corresponding warnings.
> >
> > I'd rather this be a kconfig option, so that eventually 'make
> > allmodconfig; make dtbs' also runs the schema checks. If something can
> > be enabled for allmodconfig, then builders will automatically start
> > testing it. Though the extra dependency is a problem here.
> 
> 
> The dependency on libyaml is gone.
> 
> As for the dependency on dt-schema, is it a good idea to
> pull it into the kernel tree somewhere,
> like we periodically sync scripts/dtc/ with its upstream?

I don't want that. We want DT stuff less coupled to the kernel. Doing 
that also means the person syncing dtschema into the kernel is the one 
stuck fixing any new warnings. That mostly ends up being me anyways, but 
I don't want to guarantee that. Also, that would only shift the 
dependencies to json-schema, ruamel.yaml, pylibfdt, etc. python 
packages.

For dtc, I'd actually like to remove it from the kernel.

Rob