mtd: spinand: set bitflip_threshold to 75% of ECC strength

Reporting an unclean read from SPI-NAND only when the maximum number
of correctable bitflip errors has been hit seems a bit late.
UBI LEB scrubbing, which depends on the lower MTD device reporting
correctable bitflips, then only kicks in when it's almost too late.

Set bitflip_threshold to 75% of the ECC strength, which is also the
default for raw NAND.

This is a port of linux commit
1824520e7477 (mtd: spinand: set bitflip_threshold to 75% of ECC strength)

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/2117e387260b0a96f95b8e1652ff79e0e2d71d53.1723427450.git.daniel@makrotopia.org
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu> # U-Boot port
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index b5daab21743eec4298f205446d0e9b73ff450c5b..2a2ab664c2c65da1478699d0f044f2248e6e9abc 100644 (file)
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1291,6 +1291,7 @@ static int spinand_init(struct spinand_device *spinand)
        /* Propagate ECC information to mtd_info */
        mtd->ecc_strength = nanddev_get_ecc_conf(nand)->strength;
        mtd->ecc_step_size = nanddev_get_ecc_conf(nand)->step_size;
+       mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4);
 
        ret = spinand_create_dirmaps(spinand);
        if (ret) {