mtd: nand: core: use mtd_ooblayout_xxx() helpers where appropriate

The mtd_ooblayout_xxx() helper functions have been added to avoid direct
accesses to the ecclayout field, and thus ease for future reworks.
Use these helpers in all places where the oobfree[] and eccpos[] arrays
where directly accessed.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_bch.c

@@ -196,7 +196,18 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 		printk(KERN_WARNING "eccsize %u is too large\n", eccsize);
 		goto fail;
 	}
-	if (layout->eccbytes != (eccsteps*eccbytes)) {
+
+	/*
+	 * ecc->steps and ecc->total might be used by mtd->ooblayout->ecc(),
+	 * which is called by mtd_ooblayout_count_eccbytes().
+	 * Make sure they are properly initialized before calling
+	 * mtd_ooblayout_count_eccbytes().
+	 * FIXME: we should probaly rework the sequencing in nand_scan_tail()
+	 * to avoid setting those fields twice.
+	 */
+	nand->ecc.steps = eccsteps;
+	nand->ecc.total = eccsteps * eccbytes;
+	if (mtd_ooblayout_count_eccbytes(mtd) != (eccsteps*eccbytes)) {
 		printk(KERN_WARNING "invalid ecc layout\n");
 		goto fail;
 	}