From: Wu, Josh Date: Fri, 23 Aug 2013 07:09:05 +0000 (+0800) Subject: mtd: atmel_nand: pmecc: fix bug fail to correct bit error in 1024-bytes sector X-Git-Tag: v2013.10-rc3~5^2~4^2~1 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=1bd3e2a823e196c6f8752be87fa2379c27df2ee1;p=oweals%2Fu-boot.git mtd: atmel_nand: pmecc: fix bug fail to correct bit error in 1024-bytes sector The PMECC use BCH algorithm to correct error. In BCH algorithm, the primitive polynomial value is GF(2^13) for 512-bytes sector size. And it is GF(2^14) for 1024-bytes sector size. This patch will choose correct degree of the remainders (13 or 14) for different sector size. Tested in AT91SAM9X5-EK with MLC nand flash. More detail can be refered to section 5.4.1 of: AT91SAM ARM-based Embedded MPU Application Note Signed-off-by: Josh Wu Signed-off-by: Andreas Bießmann --- diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 96aca00ebc..da83f06e47 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -827,7 +827,8 @@ static int atmel_pmecc_nand_init_params(struct nand_chip *nand, switch (mtd->writesize) { case 2048: case 4096: - host->pmecc_degree = PMECC_GF_DIMENSION_13; + host->pmecc_degree = (sector_size == 512) ? + PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14; host->pmecc_cw_len = (1 << host->pmecc_degree) - 1; host->pmecc_sector_number = mtd->writesize / sector_size; host->pmecc_bytes_per_sector = pmecc_get_ecc_bytes(