From 6c0e9101f4f181e7f1ccdfe463ee2c14c7f2a4ef Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Wed, 24 Feb 2021 09:02:10 +0100
Subject: mtd: rawnand: brcmnand: fix OOB R/W with Hamming ECC
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From: Álvaro Fernández Rojas <noltari@gmail.com>

[ Upstream commit f5200c14242fb8fa4a9b93f7fd4064d237e58785 ]

Hamming ECC doesn't cover the OOB data, so reading or writing OOB shall
always be done without ECC enabled.
This is a problem when adding JFFS2 cleanmarkers to erased blocks. If JFFS2
clenmarkers are added to the OOB with ECC enabled, OOB bytes will be changed
from ff ff ff to 00 00 00, reporting incorrect ECC errors.

Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210224080210.23686-1-noltari@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index 659eaa6f0980..5ff4291380c5 100644
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -2688,6 +2688,12 @@ static int brcmnand_attach_chip(struct nand_chip *chip)
 
 	ret = brcmstb_choose_ecc_layout(host);
 
+	/* If OOB is written with ECC enabled it will cause ECC errors */
+	if (is_hamming_ecc(host->ctrl, &host->hwcfg)) {
+		chip->ecc.write_oob = brcmnand_write_oob_raw;
+		chip->ecc.read_oob = brcmnand_read_oob_raw;
+	}
+
 	return ret;
 }
 
-- 
2.30.2