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)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150315100752.3458ccfe@bbrezillon \
--to=boris.brezillon@free-electrons.com \
--cc=andrea.scian@dave.eu \
--cc=linux-mtd@lists.infradead.org \
--cc=rnd4@dave-tech.it \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.