Re: [PATCH 1/1] Fix ECC Correction bug for SMC ordering for NDFC driver.

[Sean MacLennan <smaclennan@pikatech.com>]

On Thu, 20 Aug 2009 17:19:17 -0700
Feng Kan <fkan@amcc.com> wrote:

> Fix ECC Correction bug where the byte offset location were double
> fliped causing correction routine to toggle the wrong byte location
> in the ECC segment. The ndfc_calculate_ecc routine change the order
> of getting the ECC code.
>         /* The NDFC uses Smart Media (SMC) bytes order */
>         ecc_code[0] = p[2];
>         ecc_code[1] = p[1];
>         ecc_code[2] = p[3];
> But in the Correction algorithm when calculating the byte offset
> location, the b1 is used as the upper part of the address. Which
> again reverse the order making the final byte offset address 
> location incorrect.
> 	byte_addr = (addressbits[b1] << 4) + addressbits[b0];
> The order is change to read it in straight and let the correction
> function to revert it to SMC order.
> 
> Signed-off-by: Feng Kan <fkan@amcc.com>
> Acked-by: Victor Gallardo <vgallardo@amcc.com>
> Acked-by: Prodyut Hazarika <phazarika@amcc.com>
> ---
>  drivers/mtd/nand/ndfc.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/nand/ndfc.c b/drivers/mtd/nand/ndfc.c
> index 5906c40..d9d3e6e 100644
> --- a/drivers/mtd/nand/ndfc.c
> +++ b/drivers/mtd/nand/ndfc.c
> @@ -101,8 +101,8 @@ static int ndfc_calculate_ecc(struct mtd_info
> *mtd, wmb();
>  	ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
>  	/* The NDFC uses Smart Media (SMC) bytes order */
> -	ecc_code[0] = p[2];
> -	ecc_code[1] = p[1];
> +	ecc_code[0] = p[1];
> +	ecc_code[1] = p[2];
>  	ecc_code[2] = p[3];
>  
>  	return 0;

Acked-by: Sean MacLennan <smaclennan@pikatech.com>

Cheers,
   Sean