ofnode_read_size_cells() returns wrong size

[Heinrich Schuchardt]

Hello Simon,

I am trying to create a test for DFU on the qemu_arm64_defconfig board.
This requires saving environment variables, specifically 'preboot'.

doc/board/emulation/qemu-arm.rst suggests to create a file with:

qemu-img create -f raw envstore.img 64M

The flash can be made available to QEMU via parameter

-drive if=pflash,format=raw,index=1,file=envstore.img

64MiB is the only size that qemu-system-aarch64 accepts:
"device requires 67108864 bytes"

So I tried:

qemu-system-aarch64 -machine virt -bios u-boot.bin \
-cpu cortex-a53 -nographic \
-drive if=pflash,format=raw,index=1,file=envstore.img

But I got an error trying to save:

=> saveenv
Saving Environment to Flash... Error: start and/or end address not on
sector boundary
Error: start and/or end address not on sector boundary
Failed (1)

This seems strange for CONFIG_ENV_ADDR=0x4000000.

Debugging shows that the base address of the second flash bank is
detected as 0x400000000000000.

The device tree has:

#size-cells = <0x00000002>;
#address-cells = <0x00000002>;
flash at 0 {
        bank-width = <0x00000004>;
        reg = <0x00000000 0x00000000 0x00000000 0x04000000
               0x00000000 0x04000000 0x00000000 0x04000000>;
        compatible = "cfi-flash";
};

So that 0x400000000000000 base address is wrong.

drivers/mtd/cfi_flash.c(2478) cfi_flash_probe: addrc= 2
drivers/mtd/cfi_flash.c(2479) cfi_flash_probe: sizec= 1

So here the size of the cells is incorrectly determined as 1 by
dev_read_size_cells(dev).

The reason is that fdt_address_cells() and and fdt_size_cells() don't
walk up the tree as incorrectly assumed in
ofnode_read_size_cells() and ofnode_read_size_addr() introduced in
commit 878d68c0c357 ("dm: core: Add functions to obtain node's
address/size cells").

lib/libfdt/../../scripts/dtc/libfdt/fdt_addresses.c(42)
fdt_address_cells: FDT_ERR_NOTFOUND returning 2
lib/libfdt/../../scripts/dtc/libfdt/fdt_addresses.c(54)
fdt_size_cells: FDT_ERR_NOTFOUND returning 1

I will provide a patch for drivers/mtd/cfi_flash.c but could you,
please, take care of drivers/core/ofnode.c.

Best regards

Heinrich