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Date: Fri, 19 Sep 2014 09:34:31 -0700
From: Brian Norris <computersforpeace@gmail.com>
To: Josh Wu <josh.wu@atmel.com>
Subject: Re: [PATCH v2] mtd: atmel_nand: make PMECC lookup table and offset
 property optional
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On Thu, Sep 18, 2014 at 04:08:03PM +0800, Josh Wu wrote:
> On 9/18/2014 8:32 AM, Brian Norris wrote:
> >On Mon, Aug 18, 2014 at 03:08:40PM +0800, Josh Wu wrote:
> >>+static int pmecc_build_galois_table(int mm,
> >>+		int16_t *index_of, int16_t *alpha_to)
> >>+{
...
> >>+}
> >Is this algorithm documented? How did you come up with this?
> 
> It is not documented in datasheet. It is based BCH algorithm. But do
> you know if the soft BCH use a same table like this?

I haven't delved into the algorithms here too much. Other BCH/ECC codes
do similar steps, but either (1) there's usually a few comments about
their origin or else (2) they're transparently handled by hardware ECC
engines and software doesn't need to care about the details much.

Brian