[PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo
Mike Dunn
mikedunn at newsguy.com
Sun Nov 13 19:58:54 EST 2011
On 11/13/2011 02:18 AM, Robert Jarzmik wrote:
> I took a different approach. I check an internal docg3 register to see if the
> page was written. Or I could had have checked the Hamming code, as I don't think
> it can be 0xff whatever the pagesize 7 bytes values.
>
> The reason behind is that the Hamming code is Ham(64, 57), ie. Ham(2^6,
> 2^6-6-1). The means the 6 bits are enough to cover all codewords possibilities,
> and 0xff is not one of them.
>
> So unless a bitflip in Hamming code, 0xff in it means blank page.
Clever!
> And I think
> the ECC engine is even smarter, with the ECCCONF1_PAGE_IS_WRITTEN.
I forgot about this. If the hardware can indeed tell you, I guess this is the
best way. Sounds like I'll be updating my blank page detection.
Mike
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