Re: Device Tree Corrupted after unflatten_device_tree()

[Michael Ellerman <michael@ellerman.id.au>]

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On Tue, 2009-10-20 at 09:10 -0700, Lixin Yao wrote:
> I use a board with MPC866T and 2.6.28 Linux Kernel.  Occasionally, the
> unflattened device is corrupted after “unflatten_device_tree()” which
> causes crash of kernel when device tree is traversed later on.
> 
> I looked at the fixes in lib/lmb.c, arch/powerpc/mm,
> arch/powerpc/kernel etc since 2.6.28 to 2.6.32-r4 (the most recent
> version) and could not fix my problem.
> 
> I have had a hard time trying to determine the cause. 
> 
> arch/powerpc/kernel/setup_32.c
> 
> void __init setup_arch(char **cmdline_p)
> 
> {
> 
>         *cmdline_p = cmd_line;
> 
>         /* so udelay does something sensible, assume <= 1000 bogomips
> */
> 
>         loops_per_jiffy = 500000000 / HZ;
> 
>         unflatten_device_tree();
> 
>         /* UNFLATTENED DEVICE TREE IS CORRUPTED SOMETIMES HERE */

_In what way_ is it corrupted? Bad tree structure? Bogus node/property
values, names etc.

cheers

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