From patchwork Tue Nov 27 10:50:31 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Wu X-Patchwork-Id: 1811621 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id BC6873FCF6 for ; Tue, 27 Nov 2012 15:36:33 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TdN9r-0005Do-LT; Tue, 27 Nov 2012 15:33:11 +0000 Received: from newsmtp5.atmel.com ([204.2.163.5] helo=sjogate2.atmel.com) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TdN9n-0005DS-Rt; Tue, 27 Nov 2012 15:33:09 +0000 Received: from penbh01.corp.atmel.com ([10.168.5.31]) by sjogate2.atmel.com (8.13.6/8.13.6) with ESMTP id qARAn38U026839; Tue, 27 Nov 2012 02:49:04 -0800 (PST) Received: from penmb01.corp.atmel.com ([10.168.5.33]) by penbh01.corp.atmel.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 27 Nov 2012 18:54:15 +0800 Received: from shaarm01.corp.atmel.com ([10.217.6.34]) by penmb01.corp.atmel.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 27 Nov 2012 18:54:15 +0800 From: Josh Wu To: linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, dedekind1@gmail.com Subject: [PATCH v2] MTD: at91: atmel_nand: return bit flips for the PMECC read_page() Date: Tue, 27 Nov 2012 18:50:31 +0800 Message-Id: <1354013431-13598-1-git-send-email-josh.wu@atmel.com> X-Mailer: git-send-email 1.7.9.5 X-OriginalArrivalTime: 27 Nov 2012 10:54:15.0270 (UTC) FILETIME=[8AAD9860:01CDCC8D] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121127_103308_206672_F9F656AB X-CRM114-Status: GOOD ( 13.95 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: nicolas.ferre@atmel.com, mikedunn@newsguy.com, plagnioj@jcrosoft.com, Josh Wu X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This patch fix pmecc's read_page() to return maximum number of bitflips, 0 if uncorrectable. In the commit: 3f91e94f7f511de74c0d2abe08672ccdbdd1961c ("mtd: nand: read_page() returns max_bitflips ()"), The ecc.read_page() is changed to return the maximum number of bitflips. And when meet uncorrectable bitflips it needs to return 0. See the comment in nand.h: * @read_page: function to read a page according to the ECC generator * requirements; returns maximum number of bitflips corrected in * any single ECC step, 0 if bitflips uncorrectable, -EIO hw error Signed-off-by: Josh Wu Reviewed-by: Mike Dunn --- change since v1: 1. add detail commit message for the fix. 2. return 0 when meet uncorrectable bitflips according to Mike Dunn's suggestion. drivers/mtd/nand/atmel_nand.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index c918386..1669d27 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -723,6 +723,7 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf, struct atmel_nand_host *host = nand_chip->priv; int i, err_nbr, eccbytes; uint8_t *buf_pos; + int total_err = 0; eccbytes = nand_chip->ecc.bytes; for (i = 0; i < eccbytes; i++) @@ -750,12 +751,13 @@ normal_check: pmecc_correct_data(mtd, buf_pos, ecc, i, host->pmecc_bytes_per_sector, err_nbr); mtd->ecc_stats.corrected += err_nbr; + total_err += err_nbr; } } pmecc_stat >>= 1; } - return 0; + return total_err; } static int atmel_nand_pmecc_read_page(struct mtd_info *mtd, @@ -767,6 +769,7 @@ static int atmel_nand_pmecc_read_page(struct mtd_info *mtd, uint32_t *eccpos = chip->ecc.layout->eccpos; uint32_t stat; unsigned long end_time; + int bitflips = 0; pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST); pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE); @@ -789,11 +792,14 @@ static int atmel_nand_pmecc_read_page(struct mtd_info *mtd, } stat = pmecc_readl_relaxed(host->ecc, ISR); - if (stat != 0) - if (pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]) != 0) - return -EIO; + if (stat != 0) { + bitflips = pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]); + if (bitflips < 0) + /* uncorrectable errors */ + return 0; + } - return 0; + return bitflips; } static int atmel_nand_pmecc_write_page(struct mtd_info *mtd,