[PATCH] mtd: nand: samsung: add datasheet minimum strength requirements for a chip

[Miquel Raynal]

Samsung NAND chip K9F4G08U0D minimum ECC strength requirement is 1 bit
per 512 bytes. As the chip is not ONFI nor JEDEC and because of the lack
of these values, boards using it failed to probe the NAND controller
driver. Fix this by adding the default values if needed.

Signed-off-by: Miquel Raynal <miquel.raynal at free-electrons.com>
---
 drivers/mtd/nand/nand_samsung.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mtd/nand/nand_samsung.c b/drivers/mtd/nand/nand_samsung.c
index d348f0129ae7..5dc4fa4862d7 100644
--- a/drivers/mtd/nand/nand_samsung.c
+++ b/drivers/mtd/nand/nand_samsung.c
@@ -91,6 +91,13 @@ static void samsung_nand_decode_id(struct nand_chip *chip)
 		}
 	} else {
 		nand_decode_ext_id(chip);
+
+		/* Datasheet values for SLC Samsung K9F4G08U0D-S[I|C]B0(T00) */
+		if (nand_is_slc(chip) && chip->id.data[1] == 0xDC &&
+		    (!chip->ecc_step_ds || !chip->ecc_strength_ds)) {
+			chip->ecc_step_ds = 512;
+			chip->ecc_strength_ds = 1;
+		}
 	}
 }
 
-- 
2.11.0