Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Stefan Riedmueller <s.riedmueller@phytec.de>
To:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Vignesh Raghavendra <vigneshr@ti.com>
Cc:     linux-mtd@lists.infradead.org, Richard Weinberger <richard@nod.at>,
        linux-kernel@vger.kernel.org,
        Stefan Riedmueller <s.riedmueller@phytec.de>
Subject: [PATCH] mtd: rawnand: nand_bbt: Skip bad blocks when searching for the BBT in NAND
Date:   Thu, 25 Mar 2021 11:23:37 +0100
Message-Id: <20210325102337.481172-1-s.riedmueller@phytec.de>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

The blocks containing the bad block table can become bad as well. So
make sure to skip any blocks that are marked bad when searching for the
bad block table.

Otherwise in very rare cases where two BBT blocks wear out it might
happen that an obsolete BBT is used instead of a newer available
version.

Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
---
 drivers/mtd/nand/raw/nand=5Fbbt.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand=5Fbbt.c b/drivers/mtd/nand/raw/nand=
=5Fbbt.c
index dced32a126d9..6e25a5ce5ba9 100644
--- a/drivers/mtd/nand/raw/nand=5Fbbt.c
+++ b/drivers/mtd/nand/raw/nand=5Fbbt.c
@@ -525,6 +525,7 @@ static int search=5Fbbt(struct nand=5Fchip *this, uint8=
=5Ft *buf,
 {
 	u64 targetsize =3D nanddev=5Ftarget=5Fsize(&this->base);
 	struct mtd=5Finfo *mtd =3D nand=5Fto=5Fmtd(this);
+	struct nand=5Fbbt=5Fdescr *bd =3D this->badblock=5Fpattern;
 	int i, chips;
 	int startblock, block, dir;
 	int scanlen =3D mtd->writesize + mtd->oobsize;
@@ -560,6 +561,10 @@ static int search=5Fbbt(struct nand=5Fchip *this, uint=
8=5Ft *buf,
 			int actblock =3D startblock + dir * block;
 			loff=5Ft offs =3D (loff=5Ft)actblock << this->bbt=5Ferase=5Fshift;
=20
+			/* Check if block is marked bad */
+			if (scan=5Fblock=5Ffast(this, bd, offs, buf))
+				continue;
+
 			/* Read first page */
 			scan=5Fread(this, buf, offs, mtd->writesize, td);
 			if (!check=5Fpattern(buf, scanlen, mtd->writesize, td)) {
--=20
2.25.1