[Ltib] RE: Follow up on 4 Gig of DDR on MPC8548E

[Morrison, Tom]

>> apparently after more investigations - it looks like there is something in 
>> the ext2 driver code
>> that is mal-adjusted....I haven't talked to the guy today who was looking at 
>> that - but the ext2
>> driver code that was openning a 'virtual file' / console - had some problems 
>> mapping that
>> space - again, my gut is telling me more stronger there is a problem with 
>> signed/unsigned...
>> now deeper in the ext2 code...

> I very much doubt there is a signed/unsigned issue in ext2 or elsewhere...
>
> You have CONFIG_HIGHMEM ? What are your setting for KERNELBASE and 
> PAGE_OFFSET ?

Ben,
 
I am sorry it I alluded to ext2 code itself having a signed/unsigned problem - 
just that the problem was manifesting itself inside the ext2 code in a very 
strange way ...with something that I guessed below it that was violating 
a signed/unsigned API....
 
and I was wrong with this hunch (gotta check my hunch meter)...
It was a nuance in the configuration of inbound windows for PCI/PEX 
that was dribbling onto the memory that was consistently being i/o mapped
to the ext2 driver - which then got confused and bailed completely.
 
We now have it working as we want it to with all 4 GIG of 
DDR working as we want it.
 
Thank you for pushing us to push through the hunch and get to the 
root cause. It was a tough one to find.
 
Tom