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Message-ID: <1520460673.31298.136.camel@infradead.org>
Subject: Re: [PATCH] ubi: Reject MLC NAND
From:   David Woodhouse <dwmw2@infradead.org>
To:     Steve deRosier <derosier@gmail.com>, Pavel Machek <pavel@ucw.cz>
Cc:     Richard Weinberger <richard@nod.at>,
        Boris Brezillon <boris.brezillon@free-electrons.com>,
        dedekind1@gmail.com, tharvey@gateworks.com,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        marek.vasut@gmail.com, linux-mtd@lists.infradead.org,
        cyrille.pitchen@wedev4u.fr, computersforpeace@gmail.com
In-Reply-To: <CALLGbRK4w9Yhznt6+aqr8jptQjsp7FmbjQMPtvhh2h354n2G0A@mail.gmail.com>
References: <20180303104554.5958-1-richard@nod.at>
         <20180306231805.GA28183@amd> <6772577.AmT7QaWTNU@blindfold>
         <20180307214342.GA9852@amd>
         <CALLGbRK4w9Yhznt6+aqr8jptQjsp7FmbjQMPtvhh2h354n2G0A@mail.gmail.com>
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Date:   Wed, 07 Mar 2018 22:11:13 +0000
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On Wed, 2018-03-07 at 14:08 -0800, Steve deRosier wrote:
>=20
> To clarify one thing: the reason for this is MLC has actually never
> been supported, nor worked properly. The fact that it kinda worked was
> incidental and the cause of major problems for people due to that not
> being clear. This patch only makes it explicit and avoids people
> mistakenly trying to use UBIFS on MLC flash and risking their data and
> products. To me, that's what's important.
>=20
> This is an important patch, even if all it does is keep people from
> loosing data. It also changes the conversation from "I have a
> corrupted UBIFS device, BTW it's on MLC..." to "What can we do to get
> UBIFS to work on MLC".

This is a bug fix.

UBI on MLC never worked. It was a bug that we ever permitted it. This
is now fixed.

Actually making UBI on MLC *work* would be a feature, and wouldn't be
backported to stable. But this one is *absolutely* appropriate for a
stable backport.
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