Re: [PATCH] arm64: dts: renesas: Apply overlays to base dtbs

Rob Herring
2023-09-19T15:33:41Z

On Mon, Sep 18, 2023 at 7:08 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Rob,
>
> On Mon, Sep 11, 2023 at 11:47 PM Rob Herring <robh@kernel.org> wrote:
> > DT overlays in tree need to be applied to a base DTB to validate they
> > apply, to run schema checks on them, and to catch any errors at compile
> > time.
> >
> > Signed-off-by: Rob Herring <robh@kernel.org>
>
> Thanks for your patch!
>
> > Looks like some of these apply to multiple base DTs. I've only added them
> > to 1 base.
>
> Indeed:
> - draak-ebisu-panel-aa104xd12.dtbo applies to r8a77990-ebisu.dtb, too,
> - salvator-panel-aa104xd12.dtbo applies to all salvator-x(s) variants.
>
> So should they be added to all bases they apply to?

I'll leave that to you. All depends what combinations you want to
validate. I just don't want overlays in the kernel that don't have a
base in the kernel.

> Or, if you intend none of the composite DTBs to be consumed as-is, but
> only intend them to be created for validation, perhaps the additional
> rules should be grouped together at the bottom of the Makefile?

Folks may want the composite DTBs if their bootloader can't apply them
or they don't want to mess with it in the bootloader.

> > --- a/arch/arm64/boot/dts/renesas/Makefile
> > +++ b/arch/arm64/boot/dts/renesas/Makefile
> > @@ -64,6 +65,8 @@ dtb-$(CONFIG_ARCH_R8A779F0) += r8a779f0-spider.dtb
> >
> > dtb-$(CONFIG_ARCH_R8A779G0) += r8a779g0-white-hawk.dtb
> > dtb-$(CONFIG_ARCH_R8A779G0) += r8a779g0-white-hawk-ard-audio-da7212.dtbo
>
> Do you still need the individual *.dtbo rules? Perhaps you are
> afraid that make will auto-delete them as they are only used as
> intermediaries?

Yes you need them if you want to install the .dtbo's. I'm not sure
offhand if it matters for cleaning.

Rob