Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762AbeAGWkf (ORCPT + 1 other); Sun, 7 Jan 2018 17:40:35 -0500 Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:49245 "EHLO gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754703AbeAGWkd (ORCPT ); Sun, 7 Jan 2018 17:40:33 -0500 X-Greylist: delayed 325 seconds by postgrey-1.27 at vger.kernel.org; Sun, 07 Jan 2018 17:40:32 EST From: Chris Packham To: Ezequiel Garcia , Miquel RAYNAL CC: Ezequiel Garcia , Boris Brezillon , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , "Cyrille Pitchen" , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Kalyan Kinthada Subject: Re: [PATCHv4 1/1] mtd: nand: pxa3xx: Set FORCE_CSX bit to ARMADA370 variants Thread-Topic: [PATCHv4 1/1] mtd: nand: pxa3xx: Set FORCE_CSX bit to ARMADA370 variants Thread-Index: AQHTerIkP8EUaYVnQU2YsCVBtLeZYw== Date: Sun, 7 Jan 2018 22:35:04 +0000 Message-ID: References: <20171221231904.21140-1-chris.packham@alliedtelesis.co.nz> <20171221231904.21140-2-chris.packham@alliedtelesis.co.nz> <20171222165308.10f2fe15@xps13> Accept-Language: en-NZ, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [2001:df5:b000:22:3a2c:4aff:fe70:2b02] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Hi Miquel, Ezequiel, On 23/12/17 05:56, Ezequiel Garcia wrote: > On 22 December 2017 at 12:53, Miquel RAYNAL > wrote: >> Hello Chris, >> >> On Fri, 22 Dec 2017 12:19:04 +1300 >> Chris Packham wrote: >> >>> From: Kalyan Kinthada >>> >>> The Armada-370 based SoCs support arbitration between the NAND Flash >>> interface and NOR (i.e. devbus) on the same chip select. However there >>> are two guidelines that must be followed to avoid data corruption in >>> this scenario. >> >> Sorry to bother you again with that but, do you actually face any >> issue/data corruption with this scenario? >> > > Indeed. We need a description of a real world problem this patch is fixing. > I totally agree. The Marvell FAE used words like "data corruption" hence my re-newed interest in this. I had hoped these patches would pique the interest of someone from Marvell's engineering team with some more info on how the data corruption exhibits. I've been running some of the mtd-utils tests on my hardware and haven't detected any failures yet. I think the key would be to be doing interleaved accesses between nand and the parallel device. I've just kicked off something I think should do this on my hardware but I'm unsure as to how long I should wait for an issue to present itself. I'll leave it running for as long as I can today. If I find a failure I'll report back otherwise we can leave this patch for the mailing list archives waiting for an issue to be seen.