From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f42.google.com (mail-yw0-f42.google.com [209.85.213.42]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 427E7B6F00 for ; Mon, 22 Aug 2011 20:51:26 +1000 (EST) Received: by ywb3 with SMTP id 3so3504492ywb.15 for ; Mon, 22 Aug 2011 03:51:20 -0700 (PDT) Subject: Re: [PATCH v3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip From: Artem Bityutskiy To: b35362@freescale.com Date: Mon, 22 Aug 2011 13:53:08 +0300 In-Reply-To: <1313634783-8855-1-git-send-email-b35362@freescale.com> References: <1313634783-8855-1-git-send-email-b35362@freescale.com> Content-Type: text/plain; charset="UTF-8" Message-ID: <1314010393.2644.110.camel@sauron> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, dwmw2@infradead.org, linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2011-08-18 at 10:33 +0800, b35362@freescale.com wrote: > From: Liu Shuo > > Freescale FCM controller has a 2K size limitation of buffer RAM. In order > to support the Nand flash chip whose page size is larger than 2K bytes, > we divide a page into multi-2K pages for MTD layer driver. In that case, > we force to set the page size to 2K bytes. We convert the page address of > MTD layer driver to a real page address in flash chips and a column index > in fsl_elbc driver. We can issue any column address by UA instruction of > elbc controller. > > NOTE: Due to there is a limitation of 'Number of Partial Program Cycles in > the Same Page (NOP)', the flash chip which is supported by this workaround > have to meet below conditions. > 1. page size is not greater than 4KB > 2. 1) if main area and spare area have independent NOPs: > main area NOP : >=3 > spare area NOP : >=2 > 2) if main area and spare area have a common NOP: > NOP : >=4 Could you please also add this kind of info to the driver code comments? Does it also make sense to print a message if you do the emulation, like: pr_info("attention! emulating 2KiB NAND pages!"); -- Best Regards, Artem Bityutskiy From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yx0-f177.google.com ([209.85.213.177]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QvS6F-0003bE-P9 for linux-mtd@lists.infradead.org; Mon, 22 Aug 2011 10:51:24 +0000 Received: by yxk8 with SMTP id 8so4182177yxk.36 for ; Mon, 22 Aug 2011 03:51:20 -0700 (PDT) Subject: Re: [PATCH v3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip From: Artem Bityutskiy To: b35362@freescale.com Date: Mon, 22 Aug 2011 13:53:08 +0300 In-Reply-To: <1313634783-8855-1-git-send-email-b35362@freescale.com> References: <1313634783-8855-1-git-send-email-b35362@freescale.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Message-ID: <1314010393.2644.110.camel@sauron> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Li Yang , dwmw2@infradead.org, linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2011-08-18 at 10:33 +0800, b35362@freescale.com wrote: > From: Liu Shuo > > Freescale FCM controller has a 2K size limitation of buffer RAM. In order > to support the Nand flash chip whose page size is larger than 2K bytes, > we divide a page into multi-2K pages for MTD layer driver. In that case, > we force to set the page size to 2K bytes. We convert the page address of > MTD layer driver to a real page address in flash chips and a column index > in fsl_elbc driver. We can issue any column address by UA instruction of > elbc controller. > > NOTE: Due to there is a limitation of 'Number of Partial Program Cycles in > the Same Page (NOP)', the flash chip which is supported by this workaround > have to meet below conditions. > 1. page size is not greater than 4KB > 2. 1) if main area and spare area have independent NOPs: > main area NOP : >=3 > spare area NOP : >=2 > 2) if main area and spare area have a common NOP: > NOP : >=4 Could you please also add this kind of info to the driver code comments? Does it also make sense to print a message if you do the emulation, like: pr_info("attention! emulating 2KiB NAND pages!"); -- Best Regards, Artem Bityutskiy