[PATCH] don't scan bbt if CONFIG_NAND_BBT not set

[张忠山]

From: 张忠山 <zzs0213 at gmail.com>

when CONFIG_NAND_BBT not set, chip->scan_bbt is NULL and
NAND_SKIP_BBTSCAN not set. So barebox crashed, this is the message

    ......

    nand: ONFI param page 0 valid
    nand: ONFI flash detected
    nand: NAND device: Manufacturer ID: 0x2c, Chip ID: 0xda (Micron MT29F2G08AAD), 256MiB, page size: 2048, OOB size: 64
    prefetch abort
    pc : [<00000004>]    lr : [<23f0b8d0>]
    sp : 23ffff08  ip : 7fffffff  fp : 00000000
    r10: 04000000  r9 : 00000000  r8 : 00000001
    r7 : 23b637f8  r6 : 00000000  r5 : 23b63ad4  r4 : 23b638b4
    r3 : 00000000  r2 : fffff200  r1 : 0000000a  r0 : 23b63ad4
    Flags: nZCv  IRQs off  FIQs off  Mode SVC_32

may be the best solution is set NAND_SKIP_BBTSCAN somewhere when
CONFIG_NAND_BBT not selected, but I don't known where is the best
position.

Signed-off-by: 张忠山 <zzs0213 at gmail.com>
---
 drivers/mtd/nand/nand_base.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d249565..1dbd5bf 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3597,8 +3597,12 @@ int nand_scan_tail(struct mtd_info *mtd)
 	if (chip->options & NAND_SKIP_BBTSCAN)
 		return 0;
 
+#ifdef CONFIG_NAND_BBT
 	/* Build bad block table */
 	return chip->scan_bbt(mtd);
+#else
+	return 0;
+#endif
 }
 EXPORT_SYMBOL(nand_scan_tail);
 
-- 
1.7.9.5