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authorMike Dunn <mikedunn@newsguy.com>2012-12-07 12:07:23 -0800
committerArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2012-12-12 17:03:42 +0200
commit3c9c6d657a94f9b9aae498cb5951659cc67fd6ad (patch)
treef4969efdec7109ca179865f5839242a952141cf9 /drivers/mtd
parent440b1d73b1b49bc08e1709ee6f6ef7ba2fc1f8ba (diff)
mtd: nand/docg4: fix and improve read of factory bbt
This patch does two things related to reading the factory badblock table during initialization: (1) fix error where a non-zero return code from docg4_read_page() is assumed to be an error (it was later changed to be max_bitflips; thanks to Brian Norris for bringing this to my attention a while back), and (2) if there is an error reading the factory bbt, it tries reading another (redundant) factory bbt table. Signed-off-by: Mike Dunn <mikedunn@newsguy.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/docg4.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
index 04e5fa93735e..18fa4489e52e 100644
--- a/drivers/mtd/nand/docg4.c
+++ b/drivers/mtd/nand/docg4.c
@@ -212,6 +212,7 @@ struct docg4_priv {
#define DOCG4_T 4 /* BCH alg corrects up to 4 bit errors */
#define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */
+#define DOCG4_REDUNDANT_BBT_PAGE 24 /* page where redundant factory bbt lives */
/*
* Bytes 0, 1 are used as badblock marker.
@@ -1020,16 +1021,15 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
struct docg4_priv *doc = nand->priv;
uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0);
uint8_t *buf;
- int i, block, status;
+ int i, block;
+ __u32 eccfailed_stats = mtd->ecc_stats.failed;
buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
read_page_prologue(mtd, g4_addr);
- status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
- if (status)
- goto exit;
+ docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
/*
* If no memory-based bbt was created, exit. This will happen if module
@@ -1041,6 +1041,20 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
if (nand->bbt == NULL) /* no memory-based bbt */
goto exit;
+ if (mtd->ecc_stats.failed > eccfailed_stats) {
+ /*
+ * Whoops, an ecc failure ocurred reading the factory bbt.
+ * It is stored redundantly, so we get another chance.
+ */
+ eccfailed_stats = mtd->ecc_stats.failed;
+ docg4_read_page(mtd, nand, buf, 0, DOCG4_REDUNDANT_BBT_PAGE);
+ if (mtd->ecc_stats.failed > eccfailed_stats) {
+ dev_warn(doc->dev,
+ "The factory bbt could not be read!\n");
+ goto exit;
+ }
+ }
+
/*
* Parse factory bbt and update memory-based bbt. Factory bbt format is
* simple: one bit per block, block numbers increase left to right (msb
@@ -1060,7 +1074,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
}
exit:
kfree(buf);
- return status;
+ return 0;
}
static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)