[U-Boot] [PATCH 2/2] mtd:mxs:nand support oobsize bigger than 512

[Peng Fan]

Hi, Marek

On 1/20/2015 7:03 PM, Marek Vasut wrote:
> On Friday, December 19, 2014 at 05:39:13 AM, Peng Fan wrote:
>> If ecc chunk data size is 512 and oobsize is bigger than 512, there is
>> a chance that block_mark_bit_offset conflicts with bch ecc area.
>>
>> The following graph is modified from kernel gpmi-nand.c driver with each
>> data block 512 bytes.
>> We can see that Block Mark conflicts with ecc area from bch view.
>> We can enlarge the ecc chunk size to avoid this problem to those oobsize
>> which is larger than 512.
> What exactly is the impact of this patch for current installations of U-Boot?
> Does the NAND need to be rewritten with new content? Is the format introduced
> by this patch compatible with Linux?
The patch does not affect current installations of U-boot.  The NAND 
will not be rewritten with new content for chips whose oobsize is 
smaller than 512. To chips whose oobsize is bigger than 512, new 
format(saying gf_len is 14 and ecc chunk data size is 1024) introduced 
in this patch will be used.

This patch is to support nand chips whose oobsize bigger than 512, since 
the current mxs nand driver only supports oobisze smaller than 512. Data 
maybe corrupted if oobsize is bigger than 512 while ecc chunk data size 
is still 512, this is what this patch is try to fix. Yeah the format is 
compatible with gpmi-nand.c in linux.
> Thanks!
>
> Best regards,
> Marek Vasut
Thanks,
Peng.