mtd: nand: mxc: Fix mxc_v1 ooblayout

Commit a894cf6c ("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@free-electrons.com>
Fixes: a894cf6c ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/mxc_nand.c

@@ -876,6 +876,8 @@ static void mxc_do_addr_cycle(struct mtd_info *mtd, int column, int page_addr)
 	}
 }
 
+#define MXC_V1_ECCBYTES		5
+
 static int mxc_v1_ooblayout_ecc(struct mtd_info *mtd, int section,
 				struct mtd_oob_region *oobregion)
 {
@@ -885,7 +887,7 @@ static int mxc_v1_ooblayout_ecc(struct mtd_info *mtd, int section,
 		return -ERANGE;
 
 	oobregion->offset = (section * 16) + 6;
-	oobregion->length = nand_chip->ecc.bytes;
+	oobregion->length = MXC_V1_ECCBYTES;
 
 	return 0;
 }
@@ -907,8 +909,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
 			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;