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From: Scott Wood <scottwood@freescale.com>
To: Li Yang <leoli@freescale.com>
Cc: Artem.Bityutskiy@nokia.com, dedekind1@gmail.com,
	dwmw2@infradead.org, LiuShuo <b35362@freescale.com>,
	linux-kernel@vger.kernel.org, shuo.liu@freescale.com,
	linux-mtd@lists.infradead.org, akpm@linux-foundation.org,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 3/3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip
Date: Thu, 15 Dec 2011 11:32:40 -0600	[thread overview]
Message-ID: <4EEA2F38.2090807@freescale.com> (raw)
In-Reply-To: <CADRPPNRRXTWzBEvY=vhe9+v0b8Ntq8KNoaXFN8pQZGmMc-dJYw@mail.gmail.com>

On 12/14/2011 10:59 PM, Li Yang wrote:
> The limitation of the proposed bad block marker migration is that you
> need to make sure the migration is done and only done once.  If it is
> done more than once, the factory bad block marker is totally messed
> up.  It requires a complex mechanism to automatically guarantee the
> migration is only done once, and it still won't be 100% safe.
> 
> I would suggest we use a much easier compromise that we form the BBT
> base on the factory bad block marker on first use of the flash, and
> after that the factory bad block marker is dropped.  We just relies on
> the BBT for information about bad blocks.  Although by doing so we
> can't regenerate the BBT again,  as there is mirror for the BBT I
> don't think we have too much risk.

I have corrupted the BBT too often during development (e.g. a bug makes
all accesses fail, so the upper layers decide to mark everything bad) to
be comfortable with this.

Elsewhere in the thread I suggested a way to let the marker be in either
the bbt or in a dedicated block, depending on whether it's a development
situation where the BBT needs to be erasable.

-Scott

  reply	other threads:[~2011-12-15 17:38 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-04  4:31 [PATCH 1/3] mtd/nand : use elbc_fcm_ctrl->oob to set FPAR_MS bit of FPAR shuo.liu
2011-12-04  4:31 ` [PATCH 2/3] mtd/nand : set correct length to FBCR for a non-full-page write shuo.liu
2011-12-04  4:31 ` [PATCH 3/3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip shuo.liu
2011-12-05  6:47   ` Artem Bityutskiy
2011-12-05 19:46     ` Scott Wood
2011-12-06 11:49       ` Artem Bityutskiy
2011-12-06 11:49   ` Artem Bityutskiy
2011-12-07  0:09   ` Scott Wood
2011-12-07  3:55     ` LiuShuo
2011-12-07 19:11       ` Scott Wood
2011-12-08 10:44         ` LiuShuo
2011-12-08 18:43           ` Scott Wood
2011-12-12 21:09     ` Artem Bityutskiy
2011-12-12 21:15       ` Scott Wood
2011-12-12 21:19         ` Artem Bityutskiy
2011-12-12 21:30           ` Scott Wood
2011-12-13  2:46             ` LiuShuo
2011-12-14  8:41               ` LiuShuo
2011-12-14 20:15                 ` Scott Wood
2011-12-15  4:59                   ` Li Yang
2011-12-15 17:32                     ` Scott Wood [this message]
2011-12-16  2:44                   ` LiuShuo
2011-12-16 17:59                     ` Scott Wood
2011-12-19 11:05                       ` Li Yang
2011-12-19 16:47                         ` Scott Wood
2011-12-20  9:08                           ` Li Yang
2011-12-20 19:48                             ` Scott Wood
2011-12-17 14:35             ` Artem Bityutskiy
2011-12-19 18:38               ` Scott Wood
2011-12-19 18:42                 ` Scott Wood
2011-12-14  3:41       ` LiuShuo
2011-12-14 20:53         ` Scott Wood
2011-12-05  6:50 ` [PATCH 1/3] mtd/nand : use elbc_fcm_ctrl->oob to set FPAR_MS bit of FPAR Artem Bityutskiy
  -- strict thread matches above, loose matches on Subject: below --
2011-11-24  0:41 b35362
2011-11-24  0:41 ` [PATCH 3/3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip b35362
2011-11-24  7:37   ` Li Yang-R58472
2011-11-28 17:20     ` Scott Wood
2011-11-24  7:41   ` Artem Bityutskiy
2011-11-24  7:49     ` Li Yang-R58472
2011-11-24  8:16       ` Artem Bityutskiy
2011-11-24 10:02         ` LiuShuo
2011-11-24 11:07           ` Artem Bityutskiy
2011-11-28 21:48   ` Scott Wood
2011-11-28 21:49     ` Scott Wood

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