mtd: nand: do not scan BBT after scrub

Currently, "nand scrub" runs chip->scan_bbt at the end of
nand_erase_opts() even if NAND_SKIP_BBTSCAN flag is set.

It violates the intention of NAND_SKIP_BBTSCAN.

Move NAND_SKIP_BBTSCAN flag check to nand_block_checkbad() so that
chip->scan_bbt() is never run if NAND_SKIP_BBTSCAN is set.

Also, unset NAND_BBT_SCANNED flag instead of running chip->scan_bbt()
right after scrub.  We can be lazier here because the BBT is scanned
at the next call of nand_block_checkbad().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Scott Wood <scottwood@freescale.com>

drivers/mtd/nand/nand_base.c

@@ -634,7 +634,8 @@ static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
 {
 	struct nand_chip *chip = mtd->priv;
 
-	if (!(chip->options & NAND_BBT_SCANNED)) {
+	if (!(chip->options & NAND_SKIP_BBTSCAN) &&
+	    !(chip->options & NAND_BBT_SCANNED)) {
 		chip->options |= NAND_BBT_SCANNED;
 		chip->scan_bbt(mtd);
 	}
@@ -4325,10 +4326,6 @@ int nand_scan_tail(struct mtd_info *mtd)
 	if (!mtd->bitflip_threshold)
 		mtd->bitflip_threshold = mtd->ecc_strength;
 
-	/* Check, if we should skip the bad block table scan */
-	if (chip->options & NAND_SKIP_BBTSCAN)
-		chip->options |= NAND_BBT_SCANNED;
-
 	return 0;
 }
 EXPORT_SYMBOL(nand_scan_tail);

drivers/mtd/nand/nand_util.c

@@ -91,6 +91,7 @@ int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts)
 			kfree(chip->bbt);
 		}
 		chip->bbt = NULL;
+		chip->options &= ~NAND_BBT_SCANNED;
 	}
 
 	for (erased_length = 0;
@@ -179,9 +180,6 @@ int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts)
 	if (!opts->quiet)
 		printf("\n");
 
-	if (opts->scrub)
-		chip->scan_bbt(meminfo);
-
 	return 0;
 }