From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-108815-1520461056-2-9141058421359949728 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, ME_NOAUTH 0.01, RCVD_IN_DNSWL_MED -2.3, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='195.113.26.193', Host='atrey.karlin.mff.cuni.cz', Country='CZ', FromHeader='cz', MailFrom='cz' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: pavel@ucw.cz ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1520461056; b=ZQeALCq4hWon8Dqf/fiS9MZctPfDZ7sO9mdya0Z0J4fJp7y /wdQaAD/JUGdMysa27edDc2Gaz7J+0tR89lpMheryrnWvRyPhq7lbZbH9e4xdJKI kmzAB19ZLo+f7ZiJfbQ4btj5kLzLiOUctBSbhoCuUbq8oC7I7ncn9QO4/OYu0ymf A2ljT89pUHGYTqZTZH93+lBNBV9Qk3diXdgbSX9HtgkAzQPnsALZGNUtsBaa77XR VHkHMpOnw1TjyyG9vMBPcjYaExJZ34vdkQvWrWeLHIPHGfAPDZRYTNX9OMqAEYCC TEC+mNgg6gZ5TaKmSUpKBuI5qr/OK4O/aMO+YMg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=arctest; t= 1520461056; bh=1oHDBq1BpemT29ShMxvTnOyujmtpwENZxNTdpWuiCa0=; b=W 3/RNmX28K6A+herOAfZqA7+y1d/aOjnjZF0eM1BiNQXOcLOMWOqhkIp1IWNNkyPJ YorJzJkyIcCTHRQsa3DhIdWRVpVph5XQDRiI3RIzs0sf4uiLYM22qt9zcrZrFikI cKc26nsaLmqkMC8yYGi/CMGmX0/w7PNOpdJGEKnB5DMianLwHrpI29vF3hent/vH IPmWX/QZTGpSDFxXgWN608wSW4I7w+si1Ru04eLYn4w1nBkPOeE7lsgUSJEssBTE LqvD5+I9J+GgF2v4x6+77ZVQstBfqmRqbmcltv4eGiwDsQK9PTB+PM8We6ZfcYGJ HOtS2nGpcbkk5Pm9/BuvA== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,d=none) header.from=ucw.cz; iprev=pass policy.iprev=195.113.26.193 (atrey.karlin.mff.cuni.cz); spf=none smtp.mailfrom=pavel@ucw.cz smtp.helo=atrey.karlin.mff.cuni.cz; x-aligned-from=pass; x-category=clean score=-51 state=0; x-ptr=pass x-ptr-helo=atrey.karlin.mff.cuni.cz x-ptr-lookup=atrey.karlin.mff.cuni.cz; x-return-mx=pass smtp.domain=ucw.cz smtp.result=pass smtp_is_org_domain=yes header.domain=ucw.cz header.result=pass header_is_org_domain=yes; x-tls=pass version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,d=none) header.from=ucw.cz; iprev=pass policy.iprev=195.113.26.193 (atrey.karlin.mff.cuni.cz); spf=none smtp.mailfrom=pavel@ucw.cz smtp.helo=atrey.karlin.mff.cuni.cz; x-aligned-from=pass; x-category=clean score=-51 state=0; x-ptr=pass x-ptr-helo=atrey.karlin.mff.cuni.cz x-ptr-lookup=atrey.karlin.mff.cuni.cz; x-return-mx=pass smtp.domain=ucw.cz smtp.result=pass smtp_is_org_domain=yes header.domain=ucw.cz header.result=pass header_is_org_domain=yes; x-tls=pass version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128 Date: Wed, 7 Mar 2018 23:17:33 +0100 From: Pavel Machek To: David Woodhouse , Greg KH Cc: Steve deRosier , Richard Weinberger , Boris Brezillon , 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 Subject: Re: [PATCH] ubi: Reject MLC NAND Message-ID: <20180307221733.GE10438@amd> References: <20180303104554.5958-1-richard@nod.at> <20180306231805.GA28183@amd> <6772577.AmT7QaWTNU@blindfold> <20180307214342.GA9852@amd> <1520460673.31298.136.camel@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1520460673.31298.136.camel@infradead.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed 2018-03-07 22:11:13, David Woodhouse wrote: > > > On Wed, 2018-03-07 at 14:08 -0800, Steve deRosier wrote: > > > > 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. > > > > 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". Well, for -stable I'd suggest printk(KERN_ALERT ...) but keep the system running. > This is a bug fix. > > UBI on MLC never worked. It was a bug that we ever permitted it. This > is now fixed. Yeah, well, so lets say I have a working hardware (maybe using read-only UBI on MLC), update to next stable kernel, and now kernel refuses to see the partition. I'll certainly not consider this patch a bug fix. Removing support for hardware that "only works by mistake" may be good idea, but maybe it is slightly too surprising for a -stable. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html