From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YYyi1-0006fR-1r for linux-mtd@lists.infradead.org; Fri, 20 Mar 2015 15:19:37 +0000 Date: Fri, 20 Mar 2015 16:19:03 +0100 From: Boris Brezillon To: "Qi Wang =?UTF-8?B?546L6LW3?= (qiwang)" Subject: Re: detect and manage power cut on MLC NAND Message-ID: <20150320161903.608a79fc@bbrezillon> In-Reply-To: <71CF8D7F32C5C24C9CD1D0E02D52498A7717470C@NTXXIAMBX02.xacn.micron.com> References: <71CF8D7F32C5C24C9CD1D0E02D52498A7717444D@NTXXIAMBX02.xacn.micron.com> <71CF8D7F32C5C24C9CD1D0E02D52498A771744B0@NTXXIAMBX02.xacn.micron.com> <20150320095822.7e1979ff@bbrezillon> <550BE355.8020009@nod.at> <71CF8D7F32C5C24C9CD1D0E02D52498A7717470C@NTXXIAMBX02.xacn.micron.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Iwo Mergler , "Jeff Lauruhn \(jlauruhn\)" , "dedekind1@gmail.com" , Richard Weinberger , "rnd4@dave-tech.it" , "Zoltan Szubbocsev \(zszubbocsev\)" , "linux-mtd@lists.infradead.org" , "Frank Liu =?UTF-8?B?5YiY576k?= \(frankliu\)" , "andrea.marson@dave.eu" , "Bean Huo =?UTF-8?B?6ZyN5paM5paM?= \(beanhuo\)" List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Qi, On Fri, 20 Mar 2015 15:05:54 +0000 Qi Wang =E7=8E=8B=E8=B5=B7 (qiwang) wrote: > Hi Boris, Richard >=20 > On Fri, 20 Mar 2015 05:08 PM +0000 Richard Weinberger wrote: > > > >Am 20.03.2015 um 09:58 schrieb Boris Brezillon: > >> Hi Qi, > >> > >> On Fri, 20 Mar 2015 07:44:58 +0000 > >> Qi Wang =E7=8E=8B=E8=B5=B7 (qiwang) wrote: > >> > >>>> > >>>> I seem to remember a requirement to write pages to a block in a > >>>> monotonic fashion (low to high). Is that still the case? It > >>>> seems that the low page backup could violate that rule otherwise. > >>> > >>> Yes, pages need to be programmed from low to high. But it is possible > >>> to skip some pages. Take a example, > >>> > >>> below page program ordering is ok. > >>> Page 0, page 1, page 2, page 4, page 6, page 10, page 15, etc.. > >>> Just make sure don't turn back to program the low page is ok. > >> > >> I asked a question regarding the programming sequence in answer to Iwo, > >> but I'm not sure you were in Cc, so I'm asking it again. > >> > >> Say page 1 is paired with page 4, can we program pages in this order: > >> 1, 4, 2, 5, 3, 6, ..., so that both paired pages are programmed > >> together (the Jumbo page approach Iwo described in his mail). > > > >That's a good question. I was always told that you're not allowed > >to program pages in a non-linear manner. > > >=20 > Yes, you are right. This method isn't allowed. User can only program page > within a block from low address to high address. Do you know the reason behind this ? --=20 Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com