From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lilium.sigma-star.at ([109.75.188.150]) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1etTzi-0003ai-0s for linux-mtd@lists.infradead.org; Wed, 07 Mar 2018 08:00:20 +0000 From: Richard Weinberger To: Pavel Machek Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, cyrille.pitchen@wedev4u.fr, marek.vasut@gmail.com, boris.brezillon@free-electrons.com, computersforpeace@gmail.com, dwmw2@infradead.org, dedekind1@gmail.com, tharvey@gateworks.com, stable@vger.kernel.org Subject: Re: [PATCH] ubi: Reject MLC NAND Date: Wed, 07 Mar 2018 09:01:16 +0100 Message-ID: <6772577.AmT7QaWTNU@blindfold> In-Reply-To: <20180306231805.GA28183@amd> References: <20180303104554.5958-1-richard@nod.at> <20180306231805.GA28183@amd> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Pavel, Am Mittwoch, 7. M=E4rz 2018, 00:18:05 CET schrieb Pavel Machek: > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > > most likely lose all your data upon a power-cut or due to read/write > > disturb. > > In order to protect users from bad surprises, refuse to attach to MLC > > NAND. > >=20 > > Cc: stable@vger.kernel.org >=20 > That sounds like _really_ bad idea for stable. All it does is it > removes support for hardware that somehow works. MLC is not supported and does not work. Full stop. If someone manages to get it somehow work, either with hardware or software= =20 hacks they are on their own. Having it in stable is the only chance we have to get it into vendor kernel= s. All this patch does is representing the current state of UBI/UBIFS. In the last months I got a way too much boards with MLC NAND on my desk whe= re=20 UBIFS broke. Customers wished they had known before... Thanks, //richard From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lilium.sigma-star.at ([109.75.188.150]:35272 "EHLO lilium.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751029AbeCGH7z (ORCPT ); Wed, 7 Mar 2018 02:59:55 -0500 From: Richard Weinberger To: Pavel Machek Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, cyrille.pitchen@wedev4u.fr, marek.vasut@gmail.com, boris.brezillon@free-electrons.com, computersforpeace@gmail.com, dwmw2@infradead.org, dedekind1@gmail.com, tharvey@gateworks.com, stable@vger.kernel.org Subject: Re: [PATCH] ubi: Reject MLC NAND Date: Wed, 07 Mar 2018 09:01:16 +0100 Message-ID: <6772577.AmT7QaWTNU@blindfold> In-Reply-To: <20180306231805.GA28183@amd> References: <20180303104554.5958-1-richard@nod.at> <20180306231805.GA28183@amd> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: stable-owner@vger.kernel.org List-ID: Pavel, Am Mittwoch, 7. M�rz 2018, 00:18:05 CET schrieb Pavel Machek: > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > > most likely lose all your data upon a power-cut or due to read/write > > disturb. > > In order to protect users from bad surprises, refuse to attach to MLC > > NAND. > > > > Cc: stable@vger.kernel.org > > That sounds like _really_ bad idea for stable. All it does is it > removes support for hardware that somehow works. MLC is not supported and does not work. Full stop. If someone manages to get it somehow work, either with hardware or software hacks they are on their own. Having it in stable is the only chance we have to get it into vendor kernels. All this patch does is representing the current state of UBI/UBIFS. In the last months I got a way too much boards with MLC NAND on my desk where UBIFS broke. Customers wished they had known before... Thanks, //richard