From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Andrea Scian <andrea.scian@dave.eu>
Cc: rnd4@dave-tech.it, linux-mtd@lists.infradead.org
Subject: Re: [PATCH 1/2] mtd: nand: use a lower value for badblockbits when working with MLC NAND
Date: Sun, 15 Mar 2015 10:07:52 +0100 [thread overview]
Message-ID: <20150315100752.3458ccfe@bbrezillon> (raw)
In-Reply-To: <1425643938-24749-2-git-send-email-rnd4@dave-tech.it>
Hi Andrea,
On Fri, 6 Mar 2015 13:12:17 +0100
rnd4@dave-tech.it wrote:
> From: Andrea Scian <andrea.scian@dave.eu>
>
> MLC NANDs have more bit flips that SLC. When looking for bad block
> marker we have a lot of false positive if we check for the whole byte. To
> avoid this tolerate a few (4 here) bit flips for byte.
I'm not sure sure we want to accept 4 bitflips for all MLC NANDs. IMHO
this value should be chip dependent.
I know there is currently no way to retrieve this information, so here
are two suggestions:
1/ make this value depend on the required NAND ecc strength
(badblockbits = ecc_strength / 10 ?)
2/ let each controller change this value after nand_scan_ident
depending on the detected chip until we find a generic solution to
select this value
Best Regards,
Boris
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
next prev parent reply other threads:[~2015-03-15 9:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-06 12:12 [PATCH 0/2] Use badblockbits-like approach in nand_bbt.c rnd4
2015-03-06 12:12 ` [PATCH 1/2] mtd: nand: use a lower value for badblockbits when working with MLC NAND rnd4
2015-03-15 9:07 ` Boris Brezillon [this message]
2015-04-03 12:52 ` Andrea Scian
2015-07-23 21:24 ` Andrea Scian
2015-07-23 22:00 ` Brian Norris
2015-03-06 12:12 ` [PATCH 2/2] mtd: nand: use nand_chip badblockbits when checking bad block pattern rnd4
2015-03-15 9:18 ` Boris Brezillon
2015-10-13 10:46 ` [PATCH 0/2] Use badblockbits-like approach in nand_bbt.c Boris Brezillon
2015-10-13 18:04 ` Brian Norris
[not found] <A765B125120D1346A63912DDE6D8B6310BF69672@NTXXIAMBX02.xacn.micron.com>
2016-03-09 14:26 ` [PATCH 1/2] mtd: nand: use a lower value for badblockbits when working with MLC NAND Boris Brezillon
2016-03-09 16:37 ` Andrea Scian
2016-03-10 2:48 ` Bean Huo 霍斌斌 (beanhuo)
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