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Message-ID: <9f606cfd-6823-3232-4f96-d0bd70b17211@gmail.com>
Date:   Thu, 8 Jun 2023 18:30:52 +0200
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From:   Johan Jonker <jbx6244@gmail.com>
Subject: [PATCH v1 4/5] mtd: nand: raw: rockchip-nand-controller: fix oobfree
 offset and description
To:     miquel.raynal@bootlin.com
Cc:     richard@nod.at, vigneshr@ti.com, heiko@sntech.de,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, yifeng.zhao@rock-chips.com
References: <19bf714a-43f9-c30a-8197-91aaaf4a6e5d@gmail.com>
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The MTD framework reserves 1 or 2 bytes for the bad block marker
depending on the bus size. The rockchip-nand-controller driver
currently only supports a 8 bit bus, but reserves standard 2 bytes
for the BBM. The first free OOB byte is therefore OOB2 at offset 2.
Page address(PA) bytes are moved to the last 4 positions before
ECC. Update the description for Linux.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
---
 drivers/mtd/nand/raw/rockchip-nand-controller.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/nand/raw/rockchip-nand-controller.c b/drivers/mtd/nand/raw/rockchip-nand-controller.c
index e39431cfa..cf0fe502f 100644
--- a/drivers/mtd/nand/raw/rockchip-nand-controller.c
+++ b/drivers/mtd/nand/raw/rockchip-nand-controller.c
@@ -568,9 +568,10 @@ static int rk_nfc_write_page_raw(struct nand_chip *chip, const u8 *buf,
 		 *    BBM  OOB1 OOB2 OOB3 |......|  PA0  PA1  PA2  PA3
 		 *
 		 * The rk_nfc_ooblayout_free() function already has reserved
-		 * these 4 bytes with:
+		 * these 4 bytes together with 2 bytes for BBM
+		 * by reducing it's length:
 		 *
-		 * oob_region->offset = NFC_SYS_DATA_SIZE + 2;
+		 * oob_region->length = rknand->metadata_size - NFC_SYS_DATA_SIZE - 2;
 		 */
 		if (!i)
 			memcpy(rk_nfc_oob_ptr(chip, i),
@@ -947,12 +948,8 @@ static int rk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
 	if (section)
 		return -ERANGE;

-	/*
-	 * The beginning of the OOB area stores the reserved data for the NFC,
-	 * the size of the reserved data is NFC_SYS_DATA_SIZE bytes.
-	 */
 	oob_region->length = rknand->metadata_size - NFC_SYS_DATA_SIZE - 2;
-	oob_region->offset = NFC_SYS_DATA_SIZE + 2;
+	oob_region->offset = 2;

 	return 0;
 }
--
2.30.2