On Wed, 5 Dec 2018 21:12:46 -0200
Fabio Estevam [off-list ref] wrote:

Hi Lukasz/Rob,

On Tue, Oct 9, 2018 at 7:50 AM Lukasz Majewski [off-list ref] wrote:

quoted

+&dspi3 {
+       pinctrl-names = "default";
+       pinctrl-0 = <&pinctrl_dspi3>;
+       bus-num = <3>;
+       status = "okay";
+       spi-slave;
+
+       slave@0 {
+               compatible = "lwn,bk4";
+               spi-max-frequency = <30000000>;
+               reg = <0>;
+       };
+};  

This is causing the following dtc warning in linux-next:

  DTC     arch/arm/boot/dts/vf610-bk4.dtb
arch/arm/boot/dts/vfxxx.dtsi:550.24-563.6: Warning (spi_bus_bridge):
/soc/aips-bus@40080000/spi@400ad000: incorrect #address-cells for SPI
bus
  also defined at arch/arm/boot/dts/vf610-bk4.dts:106.8-118.3
arch/arm/boot/dts/vf610-bk4.dtb: Warning (spi_bus_reg): Failed
prerequisite 'spi_bus_bridge'

If spi-slave property is removed the warning is gone.

The spi-slave has been added according to review suggestion:
https://lkml.org/lkml/2018/9/26/836

That is the way to handle "slave" SPI operation mode across the kernel. 

At the time of development - I've checked my NXP related patches with
W=1 passed to make. No warnings observed then.

Looking at drivers/spi/spi-fsl-dspi.c I don't see the "spi-slave"
property being handled there.

Any ideas on how to fix this?

The *.dts file for Vybrid was sent and work on in parallel with the SPI
slave code implementation for Vybrid:

https://patchwork.kernel.org/patch/10680431/

Unfortunately, for the above patch I did not received any feedback
since mid September.

Thanks

Best regards,

Lukasz Majewski

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