From 13f0fd94e3cae6f8a0d9fba5d367e311edc8ebde Mon Sep 17 00:00:00 2001
From: Ilya Yanok <yanok@emcraft.com>
Date: Mon, 30 Jun 2008 15:34:40 +0200
Subject: [PATCH] NAND: Scan bad blocks lazily.
Rather than scanning on boot, scan upon the first attempt to check the
badness of a block. This speeds up boot when not using NAND, and reduces
the likelihood of needing to reflash via JTAG if NAND becomes
nonfunctional.
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
---
drivers/mtd/nand/nand_base.c | 10 +++++++---
include/linux/mtd/nand.h | 2 ++
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 7bceea8ac3..cf2f374554 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -457,6 +457,11 @@ 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;
+ }
+
if (!chip->bbt)
return chip->block_bad(mtd, ofs, getchip);
@@ -2721,10 +2726,9 @@ int nand_scan_tail(struct mtd_info *mtd)
/* Check, if we should skip the bad block table scan */
if (chip->options & NAND_SKIP_BBTSCAN)
- return 0;
+ chip->options |= NAND_BBT_SCANNED;
- /* Build bad block table */
- return chip->scan_bbt(mtd);
+ return 0;
}
/* module_text_address() isn't exported, and it's mostly a pointless
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index f9b7d36a73..2993a89e1b 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -204,6 +204,8 @@ typedef enum {
(e.g. because it needs them DMA-coherent */
#define NAND_OWN_BUFFERS 0x00040000
/* Options set by nand scan */
+/* bbt has already been read */
+#define NAND_BBT_SCANNED 0x40000000
/* Nand scan has allocated controller struct */
#define NAND_CONTROLLER_ALLOC 0x80000000
--
2.39.5