DTB file appears to have corrupted node property according to fdtdump and kernel?

[Frederik Lotter <frederik.lotter-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi,

I have a particular device tree node property which refuses to reach
the Linux kernel without corruption:

I am looking at the following call stack:

#0 of_platform_bus_create(...)
#1 of_platform_bus_create(...)
#2 of_platform_bus_create(...)
#3 of_platform_populate(...)
#4 sama5_dt_device_init(...)
#5 customize_machine(...)
#6 do_one_initcall(...)
#7 do_initcall_level(...)
#8 do_initcalls()
#9 do_basic_setup() at main.c:881
#10 kernel_init_freeable() at main.c:1004
#11 kernel_init(unused = <Value currently has no location>) at main.c:941

Once I reach the i2c node below, I can walk the properties linked list
in the debugger. Once I get to the lsm6ds3 child and the "interrupts"
property, the value is (second value corrupted as zero)

 interrupts = <0xc 0x0>;

(I am investigating this because the second value which is used as the
interrupt trigger is always zero when the driver reads it).

I have done some additional tests using the dtc and fdtdump utility to
try and isolate the issue.

>From the extract below from the preprocessed file:

   i2c1: i2c@f0018000 {
    compatible = "atmel,at91sam9x5-i2c";
    reg = <0xf0018000 0x4000>;
    interrupts = <0x13 0x4 0x6>;
    dmas = <0x2 0x2 0x9 0x2 0x2 0xa>;
    dma-names = "tx", "rx";
    pinctrl-names = "default";
    pinctrl-0 = <0x12>;
    #address-cells = <0x1>;
    #size-cells = <0x0>;
    clocks = <0x13>;
    status = "okay";
    clock-frequency = <0x61a80>;
    atmel,recover-scl = <0x14 0x1b 0x0>;
    atmel,recover-sda = <0x14 0x1a 0x0>;

    lsm6ds3@6b {
     compatible = "st,lsm6ds3";
     reg = <0x6b>;
     pinctrl-names = "default";
     pinctrl-0 = <0x15>;
     interrupt-parent = <0x16>;
     interrupts = <0xc 0x1>;
     interrupt-names = "lsm6ds_int1";
     st,drdy-int-pin = <0x1>;
    };
   };

Version: DTC 1.4.0 (ubuntu package) for manual testing.

(1)  fdtdump mix6000.dtb | grep interrupts

Thsi returns the interrupt line as:

interrupts = <0x0000000c 0x000001d0>;

(2) In the linux kernel the of_platform_populate() reads the same property as:

0x0000000c 0x00000000 with lenth=8

(3) If I take the DTS file and manually compile the DTB with the dtc
compiler, and convert it back to the DTS the correct values are shown

(4) If I change the interrupt value:

interrupts = <0xc 0x0>;

and I do:

cat <file-old.dtb> | od -t x1 > file1.txt
cat <file-mod.dtb> | od -t x1 > file2.txt
kdiff3 file1.txt file2.txt

I actually see a single hex byte change from 0x1 to 0x0.

If it was not for the faulty fdtdump output (in conjuection with the
Linux kernel zero at the same place) I would have said its definately
a kernel issue.

Any ideas?
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