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

[Marek Vasut]

On Tuesday, January 20, 2015 at 02:12:41 PM, Peng Fan wrote:
> 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 for clarifying.

Reviewed-by: Marek Vasut <marex at denx.de>

Best regards,
Marek Vasut