From 872164e41fc8dee154e5f5d22580b34e198eed69 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 6 Jun 2016 13:59:12 +0200 Subject: [PATCH] mtd: nand: sunxi: prefer 1k ECC blocks when applicable Switching to 1k ECC blocks when possible provides better resistance against concentrated bitflips. Say you have those two configurations: 1/ 16bits/512bytes 2/ 32bits/1024bytes Both of them require the same amount of ECC bytes (only true for this specific engine), but the second config allows you to correct the case where most of your bitflips are concentrated in a single 512bytes portion. This fact makes the 1k ECC block size more advantageous than the 512bytes one. Signed-off-by: Boris Brezillon --- drivers/mtd/nand/sunxi_nand.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c index b9a2e5d..bb440b9 100644 --- a/drivers/mtd/nand/sunxi_nand.c +++ b/drivers/mtd/nand/sunxi_nand.c @@ -1786,6 +1786,12 @@ static int sunxi_nand_hw_common_ecc_ctrl_init(struct mtd_info *mtd, if (!data) return -ENOMEM; + /* Prefer 1k ECC chunk over 512 ones */ + if (ecc->size == 512 && mtd->writesize > 512) { + ecc->size = 1024; + ecc->strength *= 2; + } + /* Add ECC info retrieval from DT */ for (i = 0; i < ARRAY_SIZE(strengths); i++) { if (ecc->strength <= strengths[i]) -- 2.7.4