[PATCH 4.12 03/22] mtd: nand: mxc: Fix mxc_v1 ooblayout

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

commit 3bff08dffe3115a25ce04b95ea75f6d868572c60 upstream.

Commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
introduced a bug in the OOB layout description. Even if the driver claims
that 3 ECC bytes are reserved to protect 512 bytes of data, it's actually
5 ECC bytes to protect 512+6 bytes of data (some OOB bytes are also
protected using extra ECC bytes).

Fix the mxc_v1_ooblayout_{free,ecc}() functions to reflect this behavior.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Fixes: a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mtd/nand/mxc_nand.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -877,6 +877,8 @@ static void mxc_do_addr_cycle(struct mtd
 	}
 }
 
+#define MXC_V1_ECCBYTES		5
+
 static int mxc_v1_ooblayout_ecc(struct mtd_info *mtd, int section,
 				struct mtd_oob_region *oobregion)
 {
@@ -886,7 +888,7 @@ static int mxc_v1_ooblayout_ecc(struct m
 		return -ERANGE;
 
 	oobregion->offset = (section * 16) + 6;
-	oobregion->length = nand_chip->ecc.bytes;
+	oobregion->length = MXC_V1_ECCBYTES;
 
 	return 0;
 }
@@ -908,8 +910,7 @@ static int mxc_v1_ooblayout_free(struct
 			oobregion->length = 4;
 		}
 	} else {
-		oobregion->offset = ((section - 1) * 16) +
-				    nand_chip->ecc.bytes + 6;
+		oobregion->offset = ((section - 1) * 16) + MXC_V1_ECCBYTES + 6;
 		if (section < nand_chip->ecc.steps)
 			oobregion->length = (section * 16) + 6 -
 					    oobregion->offset;