From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754639AbaIKMJt (ORCPT ); Thu, 11 Sep 2014 08:09:49 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:35527 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499AbaIKMJs (ORCPT ); Thu, 11 Sep 2014 08:09:48 -0400 Date: Thu, 11 Sep 2014 20:09:30 +0800 From: Huang Shijie To: Boris BREZILLON Cc: David Woodhouse , Brian Norris , linux-mtd@lists.infradead.org, Huang Shijie , Mike Voytovich , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Roy Lee Subject: Re: [PATCH] mtd: nand: gpmi: add proper raw access support Message-ID: <20140911120928.GA1585@localhost.localdomain> References: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 10, 2014 at 10:55:39AM +0200, Boris BREZILLON wrote: > Several MTD users (either in user or kernel space) expect a valid raw > access support to NAND chip devices. > This is particularly true for testing tools which are often touching the > data stored in a NAND chip in raw mode to artificially generate errors. > > The GPMI drivers do not implemenent raw access functions, and thus rely on > default HW_ECC scheme implementation. > The default implementation consider the data and OOB area as properly > separated in their respective NAND section, which is not true for the GPMI > controller. > In this driver/controller some OOB data are stored at the beginning of the > NAND data area (these data are called metadata in the driver), then ECC > bytes are interleaved with data chunk (which is similar to the > HW_ECC_SYNDROME scheme), and eventually the remaining bytes are used as > OOB data. > > Signed-off-by: Boris BREZILLON > --- > Hello, > > This patch is providing raw access support to the GPMI driver which is > particularly useful to run some tests on the NAND (the one coming in > mind is the mtd_nandbiterrs testsuite). > > I know this rework might break several user space tools which are relying > on the default raw access implementation (I already experienced an issue > with the kobs-ng tool provided by freescale), but many other tools will > now work as expected. If the kobs-ng can not works, there is no meaning that other tools works. So I do not think we need to implement these hooks. sorry, I will not Ack this patch. thanks Huang Shijie From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 11 Sep 2014 20:09:30 +0800 From: Huang Shijie To: Boris BREZILLON Subject: Re: [PATCH] mtd: nand: gpmi: add proper raw access support Message-ID: <20140911120928.GA1585@localhost.localdomain> References: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> Cc: 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 List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Sep 10, 2014 at 10:55:39AM +0200, Boris BREZILLON wrote: > Several MTD users (either in user or kernel space) expect a valid raw > access support to NAND chip devices. > This is particularly true for testing tools which are often touching the > data stored in a NAND chip in raw mode to artificially generate errors. > > The GPMI drivers do not implemenent raw access functions, and thus rely on > default HW_ECC scheme implementation. > The default implementation consider the data and OOB area as properly > separated in their respective NAND section, which is not true for the GPMI > controller. > In this driver/controller some OOB data are stored at the beginning of the > NAND data area (these data are called metadata in the driver), then ECC > bytes are interleaved with data chunk (which is similar to the > HW_ECC_SYNDROME scheme), and eventually the remaining bytes are used as > OOB data. > > Signed-off-by: Boris BREZILLON > --- > Hello, > > This patch is providing raw access support to the GPMI driver which is > particularly useful to run some tests on the NAND (the one coming in > mind is the mtd_nandbiterrs testsuite). > > I know this rework might break several user space tools which are relying > on the default raw access implementation (I already experienced an issue > with the kobs-ng tool provided by freescale), but many other tools will > now work as expected. If the kobs-ng can not works, there is no meaning that other tools works. So I do not think we need to implement these hooks. sorry, I will not Ack this patch. thanks Huang Shijie From mboxrd@z Thu Jan 1 00:00:00 1970 From: shijie8@gmail.com (Huang Shijie) Date: Thu, 11 Sep 2014 20:09:30 +0800 Subject: [PATCH] mtd: nand: gpmi: add proper raw access support In-Reply-To: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> References: <1410339339-25561-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <20140911120928.GA1585@localhost.localdomain> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Sep 10, 2014 at 10:55:39AM +0200, Boris BREZILLON wrote: > Several MTD users (either in user or kernel space) expect a valid raw > access support to NAND chip devices. > This is particularly true for testing tools which are often touching the > data stored in a NAND chip in raw mode to artificially generate errors. > > The GPMI drivers do not implemenent raw access functions, and thus rely on > default HW_ECC scheme implementation. > The default implementation consider the data and OOB area as properly > separated in their respective NAND section, which is not true for the GPMI > controller. > In this driver/controller some OOB data are stored at the beginning of the > NAND data area (these data are called metadata in the driver), then ECC > bytes are interleaved with data chunk (which is similar to the > HW_ECC_SYNDROME scheme), and eventually the remaining bytes are used as > OOB data. > > Signed-off-by: Boris BREZILLON > --- > Hello, > > This patch is providing raw access support to the GPMI driver which is > particularly useful to run some tests on the NAND (the one coming in > mind is the mtd_nandbiterrs testsuite). > > I know this rework might break several user space tools which are relying > on the default raw access implementation (I already experienced an issue > with the kobs-ng tool provided by freescale), but many other tools will > now work as expected. If the kobs-ng can not works, there is no meaning that other tools works. So I do not think we need to implement these hooks. sorry, I will not Ack this patch. thanks Huang Shijie