From: Artem Bityutskiy <dedekind@infradead.org>
To: Matthieu CASTET <matthieu.castet@parrot.com>
Cc: Darwin Rambo <drambo@broadcom.com>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
Adrian Hunter <adrian.hunter@nokia.com>
Subject: Re: UBIFS and hardware ECC of all FF pages of MLC NAND
Date: Fri, 25 Sep 2009 10:05:09 +0300 [thread overview]
Message-ID: <1253862309.3778.25.camel@localhost> (raw)
In-Reply-To: <4ABB921B.8090500@parrot.com>
On Thu, 2009-09-24 at 17:36 +0200, Matthieu CASTET wrote:
> Adrian Hunter a écrit :
> > Darwin Rambo wrote:
> >
> >> 2. for initial downloading, should an ECC be programmed on all FF data pages? Is there any correction advantage?
> >
> > In your case, as you have discovered, you must not program ECC for FF pages at
> > the end of eraseblocks.
> >
> The tricky part is when you read FF pages with ecc in mtd. You will get
> an ecc error.
>
> If the ecc writing is done on software you can always xor the ecc code
> to make it "FF for FF data".
> But if everything is done by hardware...
Right, which means the UBI/UBIFS flasher should be smart and skip
0xFF-ed NAND pages at the end of eraseblocks. This adds some complexity
to the flasher, thought. And here:
http://www.linux-mtd.infradead.org/doc/ubi.html#L_format_det
I even described in details the flashing algorithm with my limited
English vocabulary :-)
--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)
next prev parent reply other threads:[~2009-09-25 7:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-18 21:31 UBIFS and hardware ECC of all FF pages of MLC NAND Darwin Rambo
2009-09-24 13:20 ` Adrian Hunter
2009-09-24 14:51 ` Artem Bityutskiy
2009-09-24 15:36 ` Matthieu CASTET
2009-09-25 7:05 ` Artem Bityutskiy [this message]
2009-09-29 13:26 ` Darwin Rambo
2009-09-29 15:42 ` Artem Bityutskiy
2009-09-29 16:13 ` Darwin Rambo
2009-09-29 16:20 ` Artem Bityutskiy
2009-09-29 17:03 ` Darwin Rambo
2009-10-11 8:39 ` Artem Bityutskiy
2009-10-11 14:38 ` Darwin Rambo
2009-10-11 15:04 ` Artem Bityutskiy
2009-10-11 17:36 ` Darwin Rambo
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