Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751452AbaJBG76 (ORCPT ); Thu, 2 Oct 2014 02:59:58 -0400 Received: from mail1.bemta8.messagelabs.com ([216.82.243.203]:60600 "EHLO mail1.bemta8.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750842AbaJBG75 convert rfc822-to-8bit (ORCPT ); Thu, 2 Oct 2014 02:59:57 -0400 X-Greylist: delayed 405 seconds by postgrey-1.27 at vger.kernel.org; Thu, 02 Oct 2014 02:59:57 EDT X-Env-Sender: Iwo.Mergler@netcommwireless.com X-Msg-Ref: server-14.tower-86.messagelabs.com!1412232750!632750!1 X-Originating-IP: [220.233.131.78] X-StarScan-Received: X-StarScan-Version: 6.12.2; banners=netcommwireless.com,-,- X-VirusChecked: Checked From: Iwo Mergler To: Boris Brezillon CC: Huang Shijie , Mike Voytovich , "linux-kernel@vger.kernel.org" , Huang Shijie , "linux-mtd@lists.infradead.org" , Roy Lee , Brian Norris , David Woodhouse , "linux-arm-kernel@lists.infradead.org" Date: Thu, 2 Oct 2014 16:52:29 +1000 Subject: RE: [PATCH] mtd: nand: gpmi: add proper raw access support Thread-Topic: [PATCH] mtd: nand: gpmi: add proper raw access support Thread-Index: Ac/chSRWygnTOZO+QISWzXW2ZuzpsgBhXrFP Message-ID: References: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> <20140911120928.GA1585@localhost.localdomain> <20140911143616.3ebb025a@bbrezillon> ,<20140930100415.4834971d@bbrezillon> In-Reply-To: <20140930100415.4834971d@bbrezillon> Accept-Language: en-US, en-AU Content-Language: en-AU X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US, en-AU 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 On Tue, 30 Sep 2014 18:04:15 +1000 Boris Brezillon wrote: > Hi Iwo, > > On Mon, 29 Sep 2014 11:22:11 +1000 > Iwo Mergler wrote: > > > On Thu, 11 Sep 2014 22:36:16 +1000 > > Boris BREZILLON wrote: > > > > > > Well, I don't know about freescale specific tools, but at least I > > > have an example with mtd_nandbiterrs module. > > > This module is assuming it can write only the data part of a NAND > > > page without modifying the OOB area (see [1]), which in GPMI > > > controller case is impossible because raw write function store > > > the data as if there were no specific scheme, while there is one: > > > (metadata + n x (data_chunk + ECC bytes) + remaining_bytes). > > > > > > > Hi Boris, > > > > > > just as an aside, only the incremental bit errors test in > > nandbiterrs positively requires raw data write. > > > > The overwrite test (re-write the same page data repeatedly without > > erase), only uses raw access because I was lazy. A normal ECC write > > would do just as well. > > Okay. > Anyway, the test I'm really interested in is the incremental bit > errors test :-). > > BTW, any reason you chose to implement this test/testsuite as a > module ? > From my understanding (and tell me if I'm wrong) we could do the same > from user-space. > > Best Regards, > > Boris > Hi Boris, can't say I have good excuses, but here goes. :-) I was writing a NAND driver, so my brain was in kernel mode. It made it slightly easier to trace the operations from end-to-end. It's also possible that I didn't have an userspace at the time and had the test compiled in, my memory is a little fuzzy... Otherwise, yes, you could probably do it from userspace. I'm not sure if there is a way to determine the number of corrected bit errors for a specific page read. ECCGETSTATS seems to be global. Best regards, Iwo ______________________________________________________________________ This communication contains information which may be confidential or privileged. The information is intended solely for the use of the individual or entity named above. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited. If you have received this communication in error, please notify me by telephone immediately. ______________________________________________________________________ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/