mtd: nand: Use standard large page OOB layout when using NAND_ECC_NONE

Use the core's large page OOB layout functions when not reserving any
space for ECC bytes in the OOB layout. Fix ->nand_ooblayout_ecc_lp()
to return -ERANGE instead of a zero length in this case.
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

@@ -115,7 +115,7 @@ static int nand_ooblayout_ecc_lp(struct mtd_info *mtd, int section,
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 
-	if (section)
+	if (section || !ecc->total)
 		return -ERANGE;
 
 	oobregion->length = ecc->total;
@@ -4701,6 +4701,19 @@ int nand_scan_tail(struct mtd_info *mtd)
 			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
 			break;
 		default:
+			/*
+			 * Expose the whole OOB area to users if ECC_NONE
+			 * is passed. We could do that for all kind of
+			 * ->oobsize, but we must keep the old large/small
+			 * page with ECC layout when ->oobsize <= 128 for
+			 * compatibility reasons.
+			 */
+			if (ecc->mode == NAND_ECC_NONE) {
+				mtd_set_ooblayout(mtd,
+						&nand_ooblayout_lp_ops);
+				break;
+			}
+
 			WARN(1, "No oob scheme defined for oobsize %d\n",
 				mtd->oobsize);
 			ret = -EINVAL;