[PATCH 6/7] mtd: rawnand: sunxi: Update OOB layout to match hardware

[Samuel Holland]

When using the hardware ECC engine, the OOB data is made available in
the NFC_REG_USER_DATA registers, one 32-bit word per ECC step. Any
additional bytes are only accessible through raw reads and software
descrambling. For efficiency, and to match the vendor driver, ignore
these extra bytes.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---

 drivers/mtd/nand/raw/sunxi_nand.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 8e873f4fec9a..a3bc9f7f9e5a 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -1604,6 +1604,13 @@ static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section,
 		return 0;
 	}
 
+	/*
+	 * The controller does not provide access to OOB bytes
+	 * past the end of the ECC data.
+	 */
+	if (section == ecc->steps && ecc->engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST)
+		return -ERANGE;
+
 	oobregion->offset = section * (ecc->bytes + 4);
 
 	if (section < ecc->steps)
-- 
2.37.4