From: Andrea Scian <rnd4@dave-tech.it>
To: "Boris Brezillon" <boris.brezillon@free-electrons.com>,
"Bean Huo 霍斌斌 (beanhuo)" <beanhuo@micron.com>
Cc: "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
Brian Norris <computersforpeace@gmail.com>
Subject: Re: [PATCH 1/2] mtd: nand: use a lower value for badblockbits when working with MLC NAND
Date: Wed, 9 Mar 2016 17:37:17 +0100 [thread overview]
Message-ID: <56E0513D.5000508@dave-tech.it> (raw)
In-Reply-To: <20160309152638.0b5e9250@bbrezillon>
Il 09/03/2016 15:26, Boris Brezillon ha scritto:
> On Tue, 1 Mar 2016 14:47:21 +0000
> Bean Huo 霍斌斌 (beanhuo) <beanhuo@micron.com> wrote:
>
>> Hi, Andrea and Boris
>> This is a historical subject, and talked before.
>> From our field issues, 8 bits of bad block mark for MLC NAND is not reasonable.
>> Because of bitflip on bad block mark, regard one good block as a bad block is common
>> Issue. Especially first time boot after reflow. The solution is modified this value to 4 for MLC
>> NAND by hand, and the factory BB mark is “0x00”.
>> I think, 4 bits for MLC NAND make sense.
>
>
> I'm tempted to say "let's start with this value and see what happens in
> real world". If we want to be a bit more conservative we could decide
> to chose 2, which should address most problems too (during my tests, I
> never seen such a huge concentration of bitflips in the same byte).
>
> Brian, Andrea, what do you think?
>
I'm currently using 4 on my custom kernel.
On all datasheet I've seen factory bad block marker is 0x00 and the same
is (AFAIK) used by MTD to mark bad blocks.
Kind Regards,
--
Andrea SCIAN
DAVE Embedded Systems
next prev parent reply other threads:[~2016-03-09 16:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[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 [this message]
2016-03-10 2:48 ` Bean Huo 霍斌斌 (beanhuo)
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
2015-04-03 12:52 ` Andrea Scian
2015-07-23 21:24 ` Andrea Scian
2015-07-23 22:00 ` Brian Norris
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