diff options
| author | Brian Norris <computersforpeace@gmail.com> | 2012-06-22 16:35:45 -0700 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2012-09-29 14:51:55 +0100 |
| commit | a7e68834fc273930c17e3decaddc13acb87a7dce (patch) | |
| tree | 010ed62d3b24099960ff5f52e0e79562ec2a6f20 | |
| parent | 491ed06f334955578f0c43d298c46ea1a7ea9e1b (diff) | |
mtd: nand: use ECC, if present, when scanning OOB
scan_read_raw_oob() is used in only in places where the MTD_OPS_PLACE_OOB mode
is preferable to MTD_OPS_RAW mode, so use MTD_OPS_PLACE_OOB instead.
MTD_OPS_PLACE_OOB provides the same functionality with the potential[1] added
bonus of error correction.
This brings scan_block_full() in line with scan_block_fast() so that they
both read bad block markers with MTD_OPS_PLACE_OOB. This can help in
preventing 0xff markers (in good blocks) from being interpreted as bad
block indicators in the presence of a single bitflip.
Note that ECC error codes (EUCLEAN or EBADMSG) are already silently
ignored in all users of scan_read_raw_oob().
[1] Few drivers perform proper error correction on OOB data. In those
cases, the use of MTD_OPS_RAW vs. MTD_OPS_PLACE_OOB is not
significant.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | drivers/mtd/nand/nand_bbt.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index f5839f06cec..0e928f3efaa 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -289,14 +289,24 @@ static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs, return mtd_read(mtd, offs, len, &retlen, buf); } -/* Scan read raw data from flash */ +/** + * scan_read_raw_oob - [GENERIC] Scan data+OOB region to buffer + * @mtd: MTD device structure + * @buf: temporary buffer + * @offs: offset at which to scan + * @len: length of data region to read + * + * Scan read data from data+OOB. May traverse multiple pages, interleaving + * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest" + * ECC condition (error or bitflip). May quit on the first (non-ECC) error. + */ static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, size_t len) { struct mtd_oob_ops ops; - int res; + int res, ret = 0; - ops.mode = MTD_OPS_RAW; + ops.mode = MTD_OPS_PLACE_OOB; ops.ooboffs = 0; ops.ooblen = mtd->oobsize; @@ -306,15 +316,18 @@ static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, ops.oobbuf = buf + ops.len; res = mtd_read_oob(mtd, offs, &ops); - - if (res) - return res; + if (res) { + if (!mtd_is_bitflip_or_eccerr(res)) + return res; + else if (mtd_is_eccerr(res) || !ret) + ret = res; + } buf += mtd->oobsize + mtd->writesize; len -= mtd->writesize; offs += mtd->writesize; } - return 0; + return ret; } static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |