Subject: Re: [PATCH 3/3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip

From: LiuShuo <[email-masked]>
Date: Wed, 14 Dec 2011 11:41:17 +0800

于 2011年12月13日 05:09, Artem Bityutskiy 写道:
> On Tue, 2011-12-06 at 18:09 -0600, Scott Wood wrote:
>> On 12/03/2011 10:31 PM, [email-masked] wrote:
>>> From: Liu Shuo<[email-masked]>
>>>
>>> Freescale FCM controller has a 2K size limitation of buffer RAM. In order
>>> to support the Nand flash chip whose page size is larger than 2K bytes,
>>> we read/write 2k data repeatedly by issuing FIR_OP_RB/FIR_OP_WB and save
>>> them to a large buffer.
>>>
>>> Signed-off-by: Liu Shuo<[email-masked]>
>>> ---
>>> v3:
>>>      -remove page_size of struct fsl_elbc_mtd.
>>>      -do a oob write by NAND_CMD_RNDIN.
>>>
>>>   drivers/mtd/nand/fsl_elbc_nand.c |  243 ++++++++++++++++++++++++++++++++++----
>>>   1 files changed, 218 insertions(+), 25 deletions(-)
>> What is the plan for bad block marker migration.
I think we can use a special bbt pattern to indicate whether migration 
has been done.
(we needn't to define another marker)

Do the migration our chip->scan_bbt as follow :

/*
  * this pattern indicate that the bad block information has been migrated,
  * if this isn't found, we do the migration.
  */
static u8 migrated_bbt_pattern[] = {'M', 'b', 'b', 't', '0' };

static int fsl_elbc_bbt(struct mtd_info *mtd)
{
         if (!check_migrated_bbt_pattern())
             bad_block_info_migtrate();

          nand_default_bbt(mtd); /* default function in nand_bbt.c */
}

- LiuShuo