[PATCH RESEND stable 4.14] mtd: rawnand: brcmnand: Fixed incorrect sub-page ECC status

From: Florian Fainelli <f.fainelli@gmail.com>
To: stable@vger.kernel.org
Cc: gregkh@linuxfoundation.org, sashal@kernel.org,
	david regan <dregan@mail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Brian Norris <computersforpeace@gmail.com>,
	linux-mtd@lists.infradead.org (open list:NAND FLASH SUBSYSTEM),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH RESEND stable 4.14] mtd: rawnand: brcmnand: Fixed incorrect sub-page ECC status
Date: Wed, 23 Feb 2022 09:44:30 -0800	[thread overview]
Message-ID: <20220223174431.1083-2-f.fainelli@gmail.com> (raw)
In-Reply-To: <20220223174431.1083-1-f.fainelli@gmail.com>

From: david regan <dregan@mail.com>

commit 36415a7964711822e63695ea67fede63979054d9 upstream

The brcmnand driver contains a bug in which if a page (example 2k byte)
is read from the parallel/ONFI NAND and within that page a subpage (512
byte) has correctable errors which is followed by a subpage with
uncorrectable errors, the page read will return the wrong status of
correctable (as opposed to the actual status of uncorrectable.)

The bug is in function brcmnand_read_by_pio where there is a check for
uncorrectable bits which will be preempted if a previous status for
correctable bits is detected.

The fix is to stop checking for bad bits only if we already have a bad
bits status.

Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Signed-off-by: david regan <dregan@mail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/trinity-478e0c09-9134-40e8-8f8c-31c371225eda-1643237024774@3c-app-mailcom-lxa02
[florian: make patch apply to 4.14, file was renamed]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/mtd/nand/brcmnand/brcmnand.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index c65724d0c725..0138c0c6a4b9 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -1637,7 +1637,7 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
 					mtd->oobsize / trans,
 					host->hwcfg.sector_size_1k);
 
-		if (!ret) {
+		if (ret != -EBADMSG) {
 			*err_addr = brcmnand_read_reg(ctrl,
 					BRCMNAND_UNCORR_ADDR) |
 				((u64)(brcmnand_read_reg(ctrl,
-- 
2.25.1


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