From: Scott Wood <scottwood@freescale.com>
To: <dedekind1@gmail.com>
Cc: Artem.Bityutskiy@nokia.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, shuo.liu@freescale.com,
linux-mtd@lists.infradead.org, akpm@linux-foundation.org,
dwmw2@infradead.org
Subject: Re: [PATCH 3/3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip
Date: Mon, 19 Dec 2011 12:38:19 -0600 [thread overview]
Message-ID: <4EEF849B.7030804@freescale.com> (raw)
In-Reply-To: <1324132520.4240.26.camel@sauron.fi.intel.com>
On 12/17/2011 08:35 AM, Artem Bityutskiy wrote:
> On Mon, 2011-12-12 at 15:30 -0600, Scott Wood wrote:
>> On 12/12/2011 03:19 PM, Artem Bityutskiy wrote:
>>> On Mon, 2011-12-12 at 15:15 -0600, Scott Wood wrote:
>>>> NAND chips come from the factory with bad blocks marked at a certain
>>>> offset into each page. This offset is normally in the OOB area, but
>>>> since we change the layout from "4k data, 128 byte oob" to "2k data, 64
>>>> byte oob, 2k data, 64 byte oob" the marker is no longer in the oob. On
>>>> first use we need to migrate the markers so that they are still in the oob.
>>>
>>> Ah, I see, thanks. Are you planning to implement in-kernel migration or
>>> use a user-space tool?
>>
>> That's the kind of answer I was hoping to get from Shuo. :-)
>>
>> Most likely is a firmware-based tool, but I'd like there to be some way
>> for the tool to mark that this has happened, so that the Linux driver
>> can refuse to do non-raw accesses to a chip that isn't marked as having
>> been migrated (or at least yell loudly in the log).
>>
>> Speaking of raw accesses, these are currently broken in the eLBC
>> driver... we need some way for the generic layer to tell us what kind of
>> access it is before the transaction starts, not once it wants to read
>> out the buffer (unless we add more hacks to delay the start of a read
>> transaction until first buffer access...). We'd be better off with a
>> high-level "read page/write page" function that does the whole thing
>> (not just buffer access, but command issuance as well).
>
> It looks like currently you can re-define chip->read_page, so I guess
> you should rework MTD and make chip->write_page re-definable?
Unless something has changed very recently, there is no chip->read_page
or chip->write_page. There is chip->ecc.read_page and
chip->ecc.write_page, but they are too low-level. What we'd need to
replace is a portion of nand_do_read_ops()/nand_do_write_ops().
-Scott
next prev parent reply other threads:[~2011-12-19 18:38 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
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 [this message]
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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