Re: [PATCH 3/4] ARM: OMAP2: gpmc: Add support for BCH ECC scheme

From: Peter Korsgaard
Date: Mon Oct 15 2012 - 14:57:12 EST


>>>>> Philip, Avinash <avinashphilip@xxxxxx> writes:

> Add support for BCH ECC scheme to gpmc driver and also enabling multi
> sector read/write. This helps in doing single shot NAND page read and
> write.

> ECC engine configurations
> BCH 4 bit support
> 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32.
> 2. read => ECC engine configured in wrap mode 1 and with ecc_size0 as
> 13 and ecc_size1 as 1.

> BCH 8 bit support
> 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32.
> 2. read => ECC engine configured in wrap mode 1 and with ecc_size0 as
> 26 and ecc_size1 as 2.

> Note: For BCH8 ECC bytes set to 14 to make compatible with RBL.

On what device? In the am335x TRM (spruh73f.pdf) figure 26-15 (pg 4273)
the rom code is documented to not use any padding on the ECC bytes
(E.G. oob 2..53):

http://www.ti.com/litv/pdf/spruh73f

I see the driver in the u-boot-am33x tree (ti81xx_nand.c) seems to use
4x14 bytes as well though, so perhaps that's a bug in the documentation
instead?

--
Bye, Peter Korsgaard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/