dtc: "syntax error" linked to &{label/subnode} syntax

[Patrice CHOTARD]

Hi

I am currently converting STM32MP platforms to OF_UPSTREAM.
As we use same binary for several boards, flags CONFIG_OF_UPSTREAM_BUILD_VENDOR=y 
and CONFIG_OF_UPSTREAM_VENDOR="st" are set.

So all dts/upstream/src/arm/st/* dts files are compiled.

I am facing an issue with dts/upstream/src/arm/st/stm32mp151a-prtt1* and 
dts/upstream/src/arm/st/stm32mp15*-mec*.* files.

To be more precise, these files are using a syntax which follows this 
format &{label/subnode} to override some nodes.

This leads to DTC error: 

 AR      drivers/usb/gadget/built-in.o
  LD      u-boot
  OBJCOPY u-boot.srec
  OBJCOPY u-boot-nodtb.bin
  SYM     u-boot.sym
  DTC     dts/upstream/src/arm/st/stm32mp157c-dhcom-picoitx.dtb
  DTC     dts/upstream/src/arm/st/stm32h750i-art-pi.dtb
  DTC     dts/upstream/src/arm/st/stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dtb
  DTC     dts/upstream/src/arm/st/stm32mp157a-iot-box.dtb
  DTC     dts/upstream/src/arm/st/stm32746g-eval.dtb
  DTC     dts/upstream/src/arm/st/stm32mp151c-mecio1r0.dtb
  DTC     dts/upstream/src/arm/st/stm32mp157a-dhcor-avenger96.dtb
  DTC     dts/upstream/src/arm/st/ste-nomadik-s8815.dtb
Error: ../dts/upstream/src/arm/st/stm32mp15x-mecio1-io.dtsi:338.1-2 syntax error
FATAL ERROR: Unable to parse input tree


At line 338 in dts/upstream/src/arm/st/stm32mp15x-mecio1-io.dtsi we got :

&{qspi_bk1_pins_a/pins} {
	pinmux = <STM32_PINMUX('F', 8, AF10)>, /* QSPI_BK1_IO0 */
		 <STM32_PINMUX('F', 9, AF10)>, /* QSPI_BK1_IO1 */
		 <STM32_PINMUX('F', 7, AF9)>, /* QSPI_BK1_IO2 */
		 <STM32_PINMUX('F', 6, AF9)>; /* QSPI_BK1_IO3 */
	/delete-property/ bias-disable;
	bias-pull-up;
};

If i update it as following , the DTC compilation is OK :

&qspi_bk1_pins_a {
	pins {
		pinmux = <STM32_PINMUX('F', 8, AF10)>, /* QSPI_BK1_IO0 */
			 <STM32_PINMUX('F', 9, AF10)>, /* QSPI_BK1_IO1 */
			 <STM32_PINMUX('F', 7, AF9)>, /* QSPI_BK1_IO2 */
			 <STM32_PINMUX('F', 6, AF9)>; /* QSPI_BK1_IO3 */
		/delete-property/ bias-disable;
		bias-pull-up;
	};
};

On kernel side, the DTC compilation is ok, but not on U-Boot side. I am not able to understand the difference.

Thanks
Patrice