mtd: omap2: mtd split nand_scan in ident and tail

nand_scan calls nand_scan_tail and here we got a ecc.layout and calculate
oobavail for this layout. After calling nand_scan, we change the layout pointer
if OMAP_ECC_HAMMING_CODE_HW_ROMCODE is set. This results in not calcluated
oobavail. Mountig as jffs2 is not possible.

To fix that nand_scan has to split up in nand_scan_ident and nand_scan_tail
setting ecc.layout between these calls. So nand_scan_tail calculates oobvail
for the used layout. This is also done in serveral other platforms.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Reviewed-by: Vimal Singh <vimal.newwork@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/omap2.c

@@ -1073,9 +1073,9 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
 	/* DIP switches on some boards change between 8 and 16 bit
 	 * bus widths for flash.  Try the other width if the first try fails.
 	 */
-	if (nand_scan(&info->mtd, 1)) {
+	if (nand_scan_ident(&info->mtd, 1, NULL)) {
 		info->nand.options ^= NAND_BUSWIDTH_16;
-		if (nand_scan(&info->mtd, 1)) {
+		if (nand_scan_ident(&info->mtd, 1, NULL)) {
 			err = -ENXIO;
 			goto out_release_mem_region;
 		}
@@ -1101,6 +1101,12 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
 		info->nand.ecc.layout = &omap_oobinfo;
 	}
 
+	/* second phase scan */
+	if (nand_scan_tail(&info->mtd)) {
+		err = -ENXIO;
+		goto out_release_mem_region;
+	}
+
 #ifdef CONFIG_MTD_PARTITIONS
 	err = parse_mtd_partitions(&info->mtd, part_probes, &info->parts, 0);
 	if (err > 0)