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Subject: Re: Limited support of NAND features in MTD.
From: Artem Bityutskiy <dedekind@infradead.org>
To: David Woodhouse <dwmw2@infradead.org>
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Date: Wed, 19 Dec 2007 13:57:23 +0200
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Cc: David Brown <davidb@davidb.org>,
	=?ISO-8859-1?Q?J=F6rn?= Engel <joern@logfs.org>,
	linux-mtd@lists.infradead.org, Alexey Korolev <akorolev@infradead.org>
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On Wed, 2007-12-19 at 10:52 +0000, David Woodhouse wrote:
> On Wed, 2007-12-19 at 10:49 +0000, Alexey Korolev wrote:
> > Hmm I did not heard about this. Could you please give more details on
> > how partial page read can suffer from lack of ECC?
>=20
> If your ECC covers the whole page, you have to read the whole page in
> order to check ECC.
>=20
> Of course, if you do ECC in sub-pages in the first place, you can read
> only a single ECC block. But you still can't just read arbitrary byte
> ranges.

Sure, but as the guys showed, even this gives substantial JFFS2
performance growth. Providing their figures are correct, subpage reads
are more then worth using.

--=20
Best regards,
Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90=
=D1=80=D1=82=D1=91=D0=BC)