From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.dave-tech.it ([2.229.21.40]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YTr7e-0003Uc-TK for linux-mtd@lists.infradead.org; Fri, 06 Mar 2015 12:12:56 +0000 From: rnd4@dave-tech.it To: linux-mtd@lists.infradead.org Subject: [PATCH 2/2] mtd: nand: use nand_chip badblockbits when checking bad block pattern Date: Fri, 6 Mar 2015 13:12:18 +0100 Message-Id: <1425643938-24749-3-git-send-email-rnd4@dave-tech.it> In-Reply-To: <1425643938-24749-1-git-send-email-rnd4@dave-tech.it> References: <1425643938-24749-1-git-send-email-rnd4@dave-tech.it> Cc: boris.brezillon@free-electrons.com, Andrea Scian List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Andrea Scian Use nand_chip->badblockbits like it's used inside nand_base.c when scanning bad block markers. This is particularly useful when using MLC NAND Signed-off-by: Andrea Scian --- drivers/mtd/nand/nand_bbt.c | 19 ++++++++++++++++--- include/linux/mtd/bbm.h | 3 +++ 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index 2672643..dba7f8b 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -127,9 +127,21 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc */ static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td) { - /* Compare the pattern */ - if (memcmp(buf + td->offs, td->pattern, td->len)) - return -1; + if (likely(td->toleratedbitdiff == 0)) { + /* Compare the pattern */ + if (memcmp(buf + td->offs, td->pattern, td->len)) + return -1; + } else { + int i, nbitdiff = 0; + uint8_t tmp; + + for (i = 0; i < td->len; i++) { + tmp = buf[td->offs + i] ^ td->pattern[i]; + nbitdiff += hweight8(tmp); + if (nbitdiff > td->toleratedbitdiff) + return -1; + } + } return 0; } @@ -1309,6 +1321,7 @@ static int nand_create_badblock_pattern(struct nand_chip *this) bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1; bd->pattern = scan_ff_pattern; bd->options |= NAND_BBT_DYNAMICSTRUCT; + bd->toleratedbitdiff = 8-this->badblockbits; this->badblock_pattern = bd; return 0; } diff --git a/include/linux/mtd/bbm.h b/include/linux/mtd/bbm.h index 211ff67..0714337 100644 --- a/include/linux/mtd/bbm.h +++ b/include/linux/mtd/bbm.h @@ -48,6 +48,8 @@ * bad) block in the stored bbt * @pattern: pattern to identify bad block table or factory marked good / * bad blocks, can be NULL, if len = 0 + * @toleratedbitdiff: number of tolerated bit difference (in a byte) between + * pattern and buffer * * Descriptor for the bad block table marker and the descriptor for the * pattern which identifies good and bad blocks. The assumption is made @@ -64,6 +66,7 @@ struct nand_bbt_descr { int maxblocks; int reserved_block_code; uint8_t *pattern; + int toleratedbitdiff; }; /* Options for the bad block table descriptors */ -- 1.7.9.5