Re: [PATCH v2 2/5] arm64: dts: qcom: Add AYN QCS8550 Common

[Krzysztof Kozlowski]

On Fri, Mar 13, 2026 at 05:19:27AM +0200, Dmitry Baryshkov wrote:
> On Wed, Mar 11, 2026 at 08:39:37PM -0500, Aaron Kling wrote:
> > On Wed, Mar 11, 2026 at 7:49 PM Val Packett <val@xxxxxxxxxxxx> wrote:
> > >
> > > On 3/11/26 2:44 PM, Aaron Kling wrote:
> > >
> > > > From: Teguh Sobirin <teguh@xxxxxxxx>
> > > >
> > > > This adds a base dtb of everything common between the AYN QCS8550
> > > > devices. It is intended to be extended by device specific overlays.
> > > >
> > > > Signed-off-by: Teguh Sobirin <teguh@xxxxxxxx>
> > > > Co-developed-by: Aaron Kling <webgeek1234@xxxxxxxxx>
> > > > Signed-off-by: Aaron Kling <webgeek1234@xxxxxxxxx>
> > > > ---
> > > >   arch/arm64/boot/dts/qcom/Makefile                  |    1 +
> > > >   arch/arm64/boot/dts/qcom/qcs8550-ayntec-common.dts | 1777 ++++++++++++++++++++

Common is not a board, NAK. This could only be DTSI if you provide some
sort of HARDWARE arguments explaining the common parts of schematics or
hardware design.

> > > >   2 files changed, 1778 insertions(+)
> > > > […]
> > > > +/ {
> > > > +     model = "AYN QCS8550 Common";
> > > > +     compatible = "ayntec,qcs8550-common", "qcom,qcs8550", "qcom,sm8550";
> > >
> > > Huh?.. All existing -common files are .dtsi includes without their own
> > > model/compatible, and the compile-time "dtbo" support is only used for
> > > EL2 where we want to apply the same thing to many many devices without
> > > polluting the tree with extra glue files. I don't see why this should be
> > > a "common device" with its own compatible string, and not just a dtsi.
> > 
> > My use case for these devices is Android, using a single base dtb and
> > variant dtbo's in a single software build. Given the aosp boot image
> > v4 setup, using individual dtb's would require different vendor_boot
> > images, which would require multiple build targets. This setup allows
> > for my use case, while also having individual dtb targets for a
> > standard Linux use case. To my knowledge, the final device specific
> > dtb from this is the same as a dtb using a common dtsi.
> 
> This needs to be explained in the commit message. But do you need then a
> model/compatible in the default dtb?

Not enough. We do not add compatibles not representing actual hardware,
just to streamline boot image handling.

Plus this code is not even truly correct.

We do not write DTS to fulfill broken Android boot process.

Best regards,
Krzysztof