From patchwork Thu Feb 2 12:06:10 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Artem Bityutskiy X-Patchwork-Id: 139124 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from merlin.infradead.org (unknown [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 71EE2104785 for ; Thu, 2 Feb 2012 23:05:18 +1100 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1RsvOk-0007HQ-Q7; Thu, 02 Feb 2012 12:04:18 +0000 Received: from mail-iy0-f177.google.com ([209.85.210.177]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1RsvOh-0007HC-HH for linux-mtd@lists.infradead.org; Thu, 02 Feb 2012 12:04:16 +0000 Received: by iafj26 with SMTP id j26so3675293iaf.36 for ; Thu, 02 Feb 2012 04:04:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:subject:from:reply-to:to:cc:date:in-reply-to:references :content-type:x-mailer:mime-version; bh=ghGfdWJed24xN/zATf5llwIdwZYC/wbM+IdewsMtCN4=; b=RLqmM5kHqCmZ1Q1gsfZ1MxcSxvQG3OhdhlrIdN/+11IDfy1VQI+25Z6D9gCWLFdH7v qeFlNNrjnMO3CIbMWy3kSk69ChIroQSKICK4p5GZ9+7EF522hea6FUR4ty3fD4/q6Jg3 8oYAWh619iJBRmLSTsa6xG7omBz8PTXXyyTyI= Received: by 10.43.48.132 with SMTP id uw4mr2320360icb.17.1328184253206; Thu, 02 Feb 2012 04:04:13 -0800 (PST) Received: from [127.0.0.1] (jfdmzpr03-ext.jf.intel.com. [134.134.139.72]) by mx.google.com with ESMTPS id lu10sm3602207igc.0.2012.02.02.04.04.08 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 02 Feb 2012 04:04:11 -0800 (PST) Message-ID: <1328184370.28171.175.camel@sauron.fi.intel.com> Subject: Re: [PATCH] mtd: atmel_nand: fix access to 16 bit NAND devices From: Artem Bityutskiy To: Nicolas Ferre , "Voss, Nikolaus" , Eric =?ISO-8859-1?Q?B=E9nard?= Date: Thu, 02 Feb 2012 14:06:10 +0200 In-Reply-To: <4F265B7E.6060806@atmel.com> References: <201201251217.q0PCHmRe027024@gatekeeper.vosshq.de> <1327670996.26648.43.camel@sauron.fi.intel.com> <4F265B7E.6060806@atmel.com> X-Mailer: Evolution 3.2.3 (3.2.3-1.fc16) Mime-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.5 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dedekind1[at]gmail.com) -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.210.177 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (dedekind1[at]gmail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: "'linux-mtd@lists.infradead.org'" , "'linux-kernel@vger.kernel.org'" X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org On Mon, 2012-01-30 at 09:57 +0100, Nicolas Ferre wrote: > Artem, do you want me to prepare a patch for reverting initial commit or > you just need my "Acked-by" (feel free to add though)? OK, thanks, just pushed this patch to l2-mtd.git and add Cc to -stable, please, validate. I'll ask David to merge it to 3.3, but no guarantees - you should ping him directly if you want this to happen. URL: http://git.infradead.org/users/dedekind/l2-mtd.git/commit/21c7726c98628016c868d803a2a8e6f2d5702519 From: Artem Bityutskiy Date: Thu, 2 Feb 2012 13:54:25 +0200 Subject: [PATCH] Revert "mtd: atmel_nand: optimize read/write buffer functions" This reverts commit fb5427508abbd635e877fabdf55795488119c2d6. The reason is that it breaks 16 bits NAND flash as it was reported by Nikolaus Voss and confirmed by Eric Bénard. Nicolas Ferre alco confirmed: "After double checking with designers, I must admit that I misunderstood the way of optimizing accesses to SMC. 16 bit nand is not so common those days..." Reported-by: Nikolaus Voss Acked-by: Nicolas Ferre Signed-off-by: Artem Bityutskiy Cc: stable@kernel.org [3.1+] --- drivers/mtd/nand/atmel_nand.c | 45 +++++++++++++++++++++++++++++++++++++--- 1 files changed, 41 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 4dd056e..35b4fb5 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -161,6 +161,37 @@ static int atmel_nand_device_ready(struct mtd_info *mtd) !!host->board->rdy_pin_active_low; } +/* + * Minimal-overhead PIO for data access. + */ +static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len) +{ + struct nand_chip *nand_chip = mtd->priv; + + __raw_readsb(nand_chip->IO_ADDR_R, buf, len); +} + +static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len) +{ + struct nand_chip *nand_chip = mtd->priv; + + __raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2); +} + +static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len) +{ + struct nand_chip *nand_chip = mtd->priv; + + __raw_writesb(nand_chip->IO_ADDR_W, buf, len); +} + +static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len) +{ + struct nand_chip *nand_chip = mtd->priv; + + __raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2); +} + static void dma_complete_func(void *completion) { complete(completion); @@ -235,27 +266,33 @@ err_buf: static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len) { struct nand_chip *chip = mtd->priv; + struct atmel_nand_host *host = chip->priv; if (use_dma && len > mtd->oobsize) /* only use DMA for bigger than oob size: better performances */ if (atmel_nand_dma_op(mtd, buf, len, 1) == 0) return; - /* if no DMA operation possible, use PIO */ - memcpy_fromio(buf, chip->IO_ADDR_R, len); + if (host->board->bus_width_16) + atmel_read_buf16(mtd, buf, len); + else + atmel_read_buf8(mtd, buf, len); } static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len) { struct nand_chip *chip = mtd->priv; + struct atmel_nand_host *host = chip->priv; if (use_dma && len > mtd->oobsize) /* only use DMA for bigger than oob size: better performances */ if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0) return; - /* if no DMA operation possible, use PIO */ - memcpy_toio(chip->IO_ADDR_W, buf, len); + if (host->board->bus_width_16) + atmel_write_buf16(mtd, buf, len); + else + atmel_write_buf8(mtd, buf, len); } /*