[U-Boot] [PATCH] mxs_nand: Fix ECC strength for NAND flash with OOB size of 256

[Heiko Schocher <hs@denx.de>]

Hello Marek, Joerg,

Am 13.04.2015 10:42, schrieb Marek Vasut:
> On Monday, April 13, 2015 at 10:39:46 AM, J?rg Krause wrote:
>> Hi Heiko,
>>
>> On So, 2015-04-12 at 10:17 +0200, Heiko Schocher wrote:
>>> On the i.mx6 based aristainetos2 board a Toshiba TH58NYG3S0HBAI4
>>> is used, which has 4096 pagesize and 256b oob. The ECC strength
>>> was not correct detected by U-Boot
>>>
>>> Signed-off-by: Heiko Schocher <hs@denx.de>
>>> ---
>>>
>>>   drivers/mtd/nand/mxs_nand.c | 3 +++
>>>   1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/mtd/nand/mxs_nand.c
>>> b/drivers/mtd/nand/mxs_nand.c
>>> index 2d2b938..00bf036 100644
>>> --- a/drivers/mtd/nand/mxs_nand.c
>>> +++ b/drivers/mtd/nand/mxs_nand.c
>>> @@ -163,6 +163,9 @@ static inline uint32_t
>>> mxs_nand_get_ecc_strength(uint32_t page_data_size,
>>>
>>>                if (page_oob_size == 224)
>>>
>>>                        return 16;
>>>
>>> +
>>> +             if (page_oob_size == 256)
>>> +                     return 18;
>>>
>>>        }
>>>
>>>        return 0;
>>
>> How about calculation the ECC strength dynamically? Peng Fan from
>> Freescale send a patch doing this in December 2014 which was already
>> reviewed by Marek:
>> https://patchwork.ozlabs.org/patch/422756/
>>
>> It is also necessary to change the calculation in mxsboot...
>
> Would be nice if the patch got applied, but I think there were some
> comments and the patch was never fixed/reposted. If Heiko wants to
> do it, that'd be nice.

Hmm.. I feel, I have not much time left for fixing such things...

Joerg: You wrote on Jan. 27, 2015, 11:14 p.m.:
"I was able to fix mxsboot, but I had difficulties with round_down, which
is a macro definition in linux/kernel.h. I've copied the macro
definition to mxsboot. I will submit the patch in a seperate mail."

Did you post such a patch? Was this the onyl problem of the patch
from Peng Fan?

"I would like to see a comment or a macro for the magic number 13, which
is the value for the Galois Field, just for clarification"

I have no idea what 13 means ...

> Nice domain name btw ;-)

Indeed.

bye,
Heiko
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