From 3c9c6d657a94f9b9aae498cb5951659cc67fd6ad Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Fri, 7 Dec 2012 12:07:23 -0800 Subject: 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 Acked-by: Robert Jarzmik Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/docg4.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'drivers/mtd') 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) -- cgit v1.2.2