[U-Boot] [PATCH 0/2] mtd: nand: fix two problems related to BBT scan

[U-Boot] [PATCH 0/2] mtd: nand: fix two problems related to BBT scan

[Masahiro Yamada]

Masahiro Yamada (2):
  mtd: nand: Mark the BBT as scanned prior to calling scan_bbt again
  mtd: nand: do not scan BBT after scrub

 drivers/mtd/nand/nand_base.c | 9 +++------
 drivers/mtd/nand/nand_util.c | 4 +---
 2 files changed, 4 insertions(+), 9 deletions(-)

-- 
1.9.1

[U-Boot] [PATCH 1/2] mtd: nand: Mark the BBT as scanned prior to calling scan_bbt again

[Masahiro Yamada]

Commit 35c204d8a9d0 (nand: reinstate lazy bad block scanning)
broke NAND_BBT_USE_FLASH feature.

Its git-log claimed that it reinstated the change as by commit
fb49454b1b6c ("nand: reinstate lazy bad block scanning"), but it moved
"chip->options |= NAND_BBT_SCANNED" below "chip->scan_bbt(mtd);".

It causes recursion if scan_bbt does not find a flash based BBT
and tries to write one, and the attempt to erase the BBT area
causes a bad block check.

Reinstate commit ff49ea8977b5 (NAND: Mark the BBT as scanned prior to
calling scan_bbt.).

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Rostislav Lisovy <lisovy@merica.cz>
Cc: Heiko Schocher <hs@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
---

 drivers/mtd/nand/nand_base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d04c7ea..eaa4be1 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -635,8 +635,8 @@ 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)) {
-		chip->scan_bbt(mtd);
 		chip->options |= NAND_BBT_SCANNED;
+		chip->scan_bbt(mtd);
 	}
 
 	if (!chip->bbt)
-- 
1.9.1

[U-Boot] [PATCH 2/2] mtd: nand: do not scan BBT after scrub

[Masahiro Yamada]

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 | 7 ++-----
 drivers/mtd/nand/nand_util.c | 4 +---
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index eaa4be1..63bdf65 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/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);
diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index 024f6fb..afdd160 100644
--- a/drivers/mtd/nand/nand_util.c
+++ b/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;
 }
 
-- 
1.9.1