[RFC PATCH v2 6/6] mtd: rawnand: micron: support 8/512 on-die ECC

From: Chris Packham <chris.packham@alliedtelesis.co.nz>
To: miquel.raynal@bootlin.com, boris.brezillon@bootlin.com,
	dwmw2@infradead.org, computersforpeace@gmail.com,
	linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
	Chris Packham <chris.packham@alliedtelesis.co.nz>,
	Richard Weinberger <richard@nod.at>,
	Marek Vasut <marek.vasut@gmail.com>
Subject: [RFC PATCH v2 6/6] mtd: rawnand: micron: support 8/512 on-die ECC
Date: Tue, 19 Jun 2018 17:31:25 +1200	[thread overview]
Message-ID: <20180619053125.16792-7-chris.packham@alliedtelesis.co.nz> (raw)
In-Reply-To: <20180619053125.16792-1-chris.packham@alliedtelesis.co.nz>

Micron MT29F1G08ABAFAWP-ITE:F supports an on-die ECC with 8 bits
per 512 bytes. Add support for this combination.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
This seems deceptively easy so I've probably missed something. I have
tested with running some of the ubifs stress tests from mtd-utils and
things seem OK.

Changes in v2:
- New

 drivers/mtd/nand/raw/nand_micron.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c
index d1e8f57544a0..2164dd112f5c 100644
--- a/drivers/mtd/nand/raw/nand_micron.c
+++ b/drivers/mtd/nand/raw/nand_micron.c
@@ -240,9 +240,9 @@ static int micron_supports_on_die_ecc(struct nand_chip *chip)
 
 	/*
 	 * Some Micron NANDs have an on-die ECC of 4/512, some other
-	 * 8/512. We only support the former.
+	 * 8/512.
 	 */
-	if (chip->ecc_strength_ds != 4)
+	if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8)
 		return MICRON_ON_DIE_UNSUPPORTED;
 
 	return MICRON_ON_DIE_SUPPORTED;
@@ -274,9 +274,9 @@ static int micron_nand_init(struct nand_chip *chip)
 			return -EINVAL;
 		}
 
-		chip->ecc.bytes = 8;
+		chip->ecc.bytes = chip->ecc_strength_ds * 2;
 		chip->ecc.size = 512;
-		chip->ecc.strength = 4;
+		chip->ecc.strength = chip->ecc_strength_ds;
 		chip->ecc.algo = NAND_ECC_BCH;
 		chip->ecc.read_page = micron_nand_read_page_on_die_ecc;
 		chip->ecc.write_page = micron_nand_write_page_on_die_ecc;
-- 
2.17.1

