From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 1 Dec 2014 11:41:39 -0800 From: Brian Norris To: Boris Brezillon Subject: Re: [PATCH] mtd: gpmi: properly handle bitflips in erased pages Message-ID: <20141201194139.GI21347@ld-irv-0074> References: <1417461159-2972-1-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: <1417461159-2972-1-git-send-email-boris.brezillon@free-electrons.com> Cc: Huang Shijie , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, Roy Lee , Mike Voytovich , 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: , Hi Boris, On Mon, Dec 01, 2014 at 08:12:39PM +0100, Boris Brezillon wrote: > Brian, I really like the idea of having a generic implementation for this > feature (using read_page_raw) as you suggested here [1], but this implies > having a temporary buffer to store the page read in raw mode and keep the page > read in normal (HW ECC engine eanbled) mode, and I'm not sure we want to > allocate more buffers than we already have. Why does this require an additional buffer? If we've already noticed an ECC error, we're expected to return raw data anyway, so what's the problem with clobbering the original data with a raw version of the data? I really *really* do not want to merge another one-off attempt at "solving" this problem in the low-level driver, if at all possible. Brian P.S. Sorry for not following up on my last attempt of a generic solution. I don't think I got enough constructive feedback, other than "this does not work for me", so I didn't pursue it further. If we have the attention of more than one driver developer here (i.e., at least you and me), then I'd really like to finish this off for good (?). From mboxrd@z Thu Jan 1 00:00:00 1970 From: computersforpeace@gmail.com (Brian Norris) Date: Mon, 1 Dec 2014 11:41:39 -0800 Subject: [PATCH] mtd: gpmi: properly handle bitflips in erased pages In-Reply-To: <1417461159-2972-1-git-send-email-boris.brezillon@free-electrons.com> References: <1417461159-2972-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <20141201194139.GI21347@ld-irv-0074> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Boris, On Mon, Dec 01, 2014 at 08:12:39PM +0100, Boris Brezillon wrote: > Brian, I really like the idea of having a generic implementation for this > feature (using read_page_raw) as you suggested here [1], but this implies > having a temporary buffer to store the page read in raw mode and keep the page > read in normal (HW ECC engine eanbled) mode, and I'm not sure we want to > allocate more buffers than we already have. Why does this require an additional buffer? If we've already noticed an ECC error, we're expected to return raw data anyway, so what's the problem with clobbering the original data with a raw version of the data? I really *really* do not want to merge another one-off attempt at "solving" this problem in the low-level driver, if at all possible. Brian P.S. Sorry for not following up on my last attempt of a generic solution. I don't think I got enough constructive feedback, other than "this does not work for me", so I didn't pursue it further. If we have the attention of more than one driver developer here (i.e., at least you and me), then I'd really like to finish this off for good (?). From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932204AbaLATlp (ORCPT ); Mon, 1 Dec 2014 14:41:45 -0500 Received: from mail-pd0-f175.google.com ([209.85.192.175]:54682 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932182AbaLATlo (ORCPT ); Mon, 1 Dec 2014 14:41:44 -0500 Date: Mon, 1 Dec 2014 11:41:39 -0800 From: Brian Norris To: Boris Brezillon Cc: David Woodhouse , linux-mtd@lists.infradead.org, Huang Shijie , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mike Voytovich , Roy Lee Subject: Re: [PATCH] mtd: gpmi: properly handle bitflips in erased pages Message-ID: <20141201194139.GI21347@ld-irv-0074> References: <1417461159-2972-1-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: <1417461159-2972-1-git-send-email-boris.brezillon@free-electrons.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Boris, On Mon, Dec 01, 2014 at 08:12:39PM +0100, Boris Brezillon wrote: > Brian, I really like the idea of having a generic implementation for this > feature (using read_page_raw) as you suggested here [1], but this implies > having a temporary buffer to store the page read in raw mode and keep the page > read in normal (HW ECC engine eanbled) mode, and I'm not sure we want to > allocate more buffers than we already have. Why does this require an additional buffer? If we've already noticed an ECC error, we're expected to return raw data anyway, so what's the problem with clobbering the original data with a raw version of the data? I really *really* do not want to merge another one-off attempt at "solving" this problem in the low-level driver, if at all possible. Brian P.S. Sorry for not following up on my last attempt of a generic solution. I don't think I got enough constructive feedback, other than "this does not work for me", so I didn't pursue it further. If we have the attention of more than one driver developer here (i.e., at least you and me), then I'd really like to finish this off for good (?).