Re: linux-next: build warnings after merge of the renesas tree

On Tue, May 6, 2025 at 5:05 AM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Stephen,
>
> On Tue, 6 May 2025 at 11:20, Stephen Rothwell <[email protected]> wrote:
> > After merging the renesas tree, today's linux-next build (arm64 defconfig)
> > produced these warnings:
> >
> > arch/arm64/boot/dts/renesas/r8a779g0.dtsi:1269.24-1283.5: Warning (spi_bus_bridge): /soc/spi@e6ea0000: incorrect #address-cells for SPI bus
> >   also defined at arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts:463.9-478.3
> > arch/arm64/boot/dts/renesas/r8a779g0.dtsi:1269.24-1283.5: Warning (spi_bus_bridge): /soc/spi@e6ea0000: incorrect #size-cells for SPI bus
> >   also defined at arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dts:463.9-478.3
> > arch/arm64/boot/dts/renesas/r8a779g3-sparrow-hawk.dtb: Warning (spi_bus_reg): Failed prerequisite 'spi_bus_bridge'
> >
> > Introduced by commit
> >
> >   c29748ccad88 ("arm64: dts: renesas: sparrow-hawk: Add MSIOF Sound support")
>
> Thanks, this is a known conflict between SPI bus bindings and dtc:
>   - Serial engines that can be SPI controllers must use "spi" as their
>     node names,
>   - Dtc assumes nodes named "spi" are always SPI controllers.

I think you can disable 'spi_bus_bridge' warning by overriding or
appending DTC_FLAGS in arch/arm64/boot/dts/renesas/Makefile.

Rob