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

[Rob Herring <robh@kernel.org>]

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.

>
> [1] https://lore.kernel.org/all/20210913145146.766080-1-robh@kernel.org/
>
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: linux-kbuild@vger.kernel.org
> Co-developed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  Makefile | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index c43d825a3c4c..0942922384c4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1365,11 +1365,17 @@ endif
>
>  ifneq ($(dtstree),)
>
> -%.dtb: include/config/kernel.release scripts_dtc
> -       $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
> +ifneq ($(VALIDATE_DT),)
> +DT_YAML = $(dtstree)/$*.dt.yaml

.dt.yaml files are deprecated now. This probably doesn't do anything.

> +DT_CHECK = dt_binding_check
> +export CHECK_DTBS=y
> +endif
>
> -%.dtbo: include/config/kernel.release scripts_dtc
> -       $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
> +%.dtb: include/config/kernel.release scripts_dtc $(DT_CHECK)
> +       $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(DT_YAML)
> +
> +%.dtbo: include/config/kernel.release scripts_dtc $(DT_CHECK)
> +       $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(DT_YAML)
>
>  PHONY += dtbs dtbs_install dtbs_check
>  dtbs: include/config/kernel.release scripts_dtc
> @@ -1654,6 +1660,10 @@ help:
>         @echo  '                3: more obscure warnings, can most likely be ignored'
>         @echo  '                e: warnings are being treated as errors'
>         @echo  '                Multiple levels can be combined with W=12 or W=123'
> +       @$(if $(dtstree), \
> +               echo '  make VALIDATE_DT=y [targets] Validate all DT processsed during the build'; \

Typo.


> +               echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
> +               )
>         @echo  ''
>         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
>         @echo  'For further info see the ./README file'
> --
> 2.35.1
>