From patchwork Wed Dec 2 10:38:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 551307 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2001:1868:205::9]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id F39EC14016A for ; Wed, 2 Dec 2015 21:40:56 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a44op-0005CM-Eo; Wed, 02 Dec 2015 10:39:27 +0000 Received: from dec59.ruk.cuni.cz ([2001:718:1e03:4::11]) by bombadil.infradead.org with smtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a44o9-0004ON-RT for linux-mtd@lists.infradead.org; Wed, 02 Dec 2015 10:38:50 +0000 Received: (qmail 71864 invoked by uid 2313); 2 Dec 2015 10:38:20 -0000 Date: 2 Dec 2015 10:38:20 -0000 MBOX-Line: From 2236d87ad516f118f58eb5df232d441f970c4499 Mon Sep 17 00:00:00 2001 Message-Id: <2236d87ad516f118f58eb5df232d441f970c4499.1449052427.git.hramrach@gmail.com> In-Reply-To: References: From: Michal Suchanek Subject: [PATCH v6 06/10] mtd: spi-nor: simplify write loop To: Heiner Kallweit , David Woodhouse , Brian Norris , Han Xu , Mark Brown , Michal Suchanek , Boris Brezillon , Javier Martinez Canillas , "Rafal Milecki" , Jagan Teki , "Andrew F. Davis" , Mika Westerberg , Gabor Juhos , "Bean Huo " , Furquan Shaikh , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151202_023846_676710_B0769B51 X-CRM114-Status: GOOD ( 12.56 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [2001:718:1e03:4:0:0:0:11 listed in] [list.dnswl.org] 0.7 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.0 DKIM_ADSP_CUSTOM_MED No valid author signature, adsp_override is CUSTOM_MED 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (hramrach[at]gmail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.9 NML_ADSP_CUSTOM_MED ADSP custom_med hit, and not from a mailing list X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org The spi-nor write loop assumes that what is passed to the hardware driver write() is what gets written. When write() writes less than page size at once data is dropped on the floor. Check the amount of data writen and exit if it does not match requested amount. Signed-off-by: Michal Suchanek --- - add warning when writing incomplete pages - refuse to continue writing when full page was not written --- drivers/mtd/spi-nor/spi-nor.c | 58 +++++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 33 deletions(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 3d02803..115c123 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1005,8 +1005,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { struct spi_nor *nor = mtd_to_spi_nor(mtd); - u32 page_offset, page_size, i; - int ret; + size_t page_offset, page_remain, i; + ssize_t ret; dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len); @@ -1014,45 +1014,37 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, if (ret) return ret; - write_enable(nor); - - page_offset = to & (nor->page_size - 1); + for (i = 0; i < len; ) { + ssize_t written; - /* do all the bytes fit onto one page? */ - if (page_offset + len <= nor->page_size) { - ret = nor->write(nor, to, len, buf); - if (ret < 0) - goto write_err; - *retlen += ret; - } else { + page_offset = to & (nor->page_size - 1); + WARN_ONCE(page_offset, + "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.", + page_offset); /* the size of data remaining on the first page */ - page_size = nor->page_size - page_offset; - ret = nor->write(nor, to, page_size, buf); + page_remain = min_t(size_t, + nor->page_size - page_offset, len - i); + + write_enable(nor); + ret = nor->write(nor, to + i, page_remain, buf + i); if (ret < 0) goto write_err; - *retlen += ret; - - /* write everything in nor->page_size chunks */ - for (i = ret; i < len; ) { - page_size = len - i; - if (page_size > nor->page_size) - page_size = nor->page_size; - - ret = spi_nor_wait_till_ready(nor); - if (ret) - goto write_err; + written = ret; - write_enable(nor); - - ret = nor->write(nor, to + i, page_size, buf + i); - if (ret < 0) - goto write_err; - *retlen += ret; - i += ret; + ret = spi_nor_wait_till_ready(nor); + if (ret) + goto write_err; + *retlen += written; + i += written; + if (written != page_remain) { + dev_err(nor->dev, + "While writing %zu bytes written %zd bytes\n", + page_remain, written); + ret = -EIO; + goto write_err; } } - ret = spi_nor_wait_till_ready(nor); write_err: spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE); return ret;