From e0377cdebaf3913bff693c9eea17ff6eb4d7abc8 Mon Sep 17 00:00:00 2001 From: Aaron Sierra Date: Wed, 14 Jan 2015 17:41:31 -0600 Subject: mtd: nand: Request strength instead of bytes for soft BCH Previously, we requested that drivers pass ecc.size and ecc.bytes when using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC strength required for its NAND, so each driver would need to perform a strength-to-bytes calculation. Avoid duplicating this calculation in each driver by asking drivers to pass ecc.size and ecc.strength so that the strength-to-bytes calculation need only be implemented once. This reverts/generalizes this commit: mtd: nand: Base BCH ECC bytes on required strength Signed-off-by: Aaron Sierra Reviewed-by: Boris Brezillon Signed-off-by: Brian Norris --- drivers/mtd/nand/nand_base.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (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 3f24b587304f..f6af96926f00 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -4037,22 +4037,24 @@ int nand_scan_tail(struct mtd_info *mtd) ecc->read_oob = nand_read_oob_std; ecc->write_oob = nand_write_oob_std; /* - * Board driver should supply ecc.size and ecc.bytes values to - * select how many bits are correctable; see nand_bch_init() - * for details. Otherwise, default to 4 bits for large page - * devices. + * Board driver should supply ecc.size and ecc.strength values + * to select how many bits are correctable. Otherwise, default + * to 4 bits for large page devices. */ if (!ecc->size && (mtd->oobsize >= 64)) { ecc->size = 512; - ecc->bytes = DIV_ROUND_UP(13 * ecc->strength, 8); + ecc->strength = 4; } + + /* See nand_bch_init() for details. */ + ecc->bytes = DIV_ROUND_UP( + ecc->strength * fls(8 * ecc->size), 8); ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes, &ecc->layout); if (!ecc->priv) { pr_warn("BCH ECC initialization failed!\n"); BUG(); } - ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size); break; case NAND_ECC_NONE: -- cgit v1.2.3-55-g7522