From c46f6483d21e93400e4a110de7902830173d53b0 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 30 Aug 2011 18:45:38 -0700 Subject: mtd: support reading OOB without ECC This fixes issues with `nanddump -n' and the MEMREADOOB[64] ioctls on hardware that performs error correction when reading only OOB data. A driver for such hardware needs to know when we're doing a RAW vs. a normal write, but mtd_do_read_oob does not pass such information to the lower layers (e.g., NAND). We should pass MTD_OOB_RAW or MTD_OOB_PLACE based on the MTD file mode. For now, most drivers can get away with just setting: chip->ecc.read_oob_raw = chip->ecc.read_oob This is done by default; but for systems that behave as described above, you must supply your own replacement function. This was tested with nandsim as well as on actual SLC NAND. Signed-off-by: Brian Norris Cc: Jim Quinlan Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/nand_base.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/mtd/nand/nand_base.c') diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index b61a7c7bd097..ad40607f5f24 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -1787,7 +1787,10 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from, page = realpage & chip->pagemask; while (1) { - sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd); + if (ops->mode == MTD_OOB_RAW) + sndcmd = chip->ecc.read_oob_raw(mtd, chip, page, sndcmd); + else + sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd); len = min(len, readlen); buf = nand_transfer_oob(chip, buf, ops, len); @@ -3385,6 +3388,8 @@ int nand_scan_tail(struct mtd_info *mtd) } /* For many systems, the standard OOB write also works for raw */ + if (!chip->ecc.read_oob_raw) + chip->ecc.read_oob_raw = chip->ecc.read_oob; if (!chip->ecc.write_oob_raw) chip->ecc.write_oob_raw = chip->ecc.write_oob; -- cgit v1.2.1