[BUG] pxa3xx: wait time out when scanning for bb

[Sean Nyekjaer]

Hi Miquel
>>> I am very sorry for the delay but it took me some time to figure a
>>> way to reproduce your situation until I started doing the exact
>>> sequence I asked you to follow. It turns out there was a nasty error
>>> in the parser so you could not observe the last blocks of your chip
>>> because I messed up with high addresses.
>> Fantastic always nice to be able to reproduce the issue. Glad to be
>> able to help :-)
>>
>>> I updated the Github branch [1], can you rebase on top of it? I think
>>> this time we should get something :)
>> I just did a quick boot with the new commits, and the kernel is able
>> to find the bbt table :-)
> Good ! :-)
>
> So with nand-ecc-mode = "none" + on-flash-bbt, there is no more issue,
> right?
No more issue with reading the bbt :-)
>
>> I also tried booting with ECC enabled and with that enabled the
>> driver is unable to read the bbt and marked all blocks bad.
> And if I understand correctly, if you remove nand-ecc-mode = "none" (or
> set it to "hw"), the kernel fails to find the BBT, that is right?
Yes.
>
> As I was not expecting such a quick answer, I did push another patch
> after sending my email that fixes an issue in mtdcore.c, please check
> you have it (there are a few "fixup!" patches, and on top of them you
> must find one which is a well-formatted patch about
> mtd_check_oob_ops()).
I have rebased on top of 9aee88a618f8 mtd: Fix mtd_check_oob_ops()
>
> I learned that today: to get a prompt while all blocks are bad, you can
> add:
>
>      chip->options |= NAND_SKIP_BBTSCAN;
>
> Before nand_scan_tail().
>
> If you can reach a prompt with the failing configuration and when you
> will have the time, I will welcome a dump of the same area as before
> so we will try to understand what is wrong now ! :)
Nice one, a lot easier to read whats happens

nanddump of BBT without ECC enabled:
https://gist.github.com/anonymous/627e5be058ed93c106d61641f6aa5da0

nanddump of BBT with ECC enabled:
https://gist.github.com/anonymous/76b3240f156c6547cf76d59f2aae49fe
bootsnippet with ECC and NAND_SKIP_BBTSCAN enabled.
https://gist.github.com/anonymous/0d9be95cd9c36ff006f7aa03e7c2cc85

Please let me know what traces you need to fix the ECC :-)

/Sean