[U-Boot] [PATCH] MTD: atmel_nand: support for software BCH ECC

[Andreas Bießmann]

Hi Bo,

On 09/04/2013 02:11 PM, Bo Shen wrote:
> Hi Andreas,
> 
> On 9/4/2013 6:23 PM, Andreas Bießmann wrote:
>> Hi Bo,
>>
>> On 08/28/2013 04:54 PM, Bo Shen wrote:
>>> Add possible to use software BCH ECC for atmel nand driver
>>>
>>> Signed-off-by: Bo Shen <voice.shen at gmail.com>
>>>
>>> ---
>>>   drivers/mtd/nand/atmel_nand.c |    4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/mtd/nand/atmel_nand.c
>>> b/drivers/mtd/nand/atmel_nand.c
>>> index 96aca00..52efbee 100644
>>> --- a/drivers/mtd/nand/atmel_nand.c
>>> +++ b/drivers/mtd/nand/atmel_nand.c
>>> @@ -1177,7 +1177,11 @@ int atmel_nand_chip_init(int devnum, ulong
>>> base_addr)
>>>       mtd->priv = nand;
>>>       nand->IO_ADDR_R = nand->IO_ADDR_W = (void  __iomem *)base_addr;
>>>
>>> +#ifdef CONFIG_NAND_ECC_BCH
>>> +    nand->ecc.mode = NAND_ECC_SOFT_BCH;
>>> +#else
>>>       nand->ecc.mode = NAND_ECC_SOFT;
>>> +#endif
>>
>> I don't think this is enough for sw supported bch. Where do you feed the
>> libbch?
> 
> Yes, we need libbch.
> 
> If we really want to enable software BCH support. It also need add
> following two options in board configuration file.
> ---8>---
> #define CONFIG_NAND_ECC_BCH
> #define CONFIG_BCH
> ---<8---
> 
> So, this patch give us option to enable software BCH.

got it. So the NAND_ECC_BCH is the adoption for the SW BCH correction in
mtd layer. I understand that this would be helpful for at91 SoC without
PMECC HW. But there is no user currently, so I hesitate to apply this.

Best regards

Andreas Bießmann