From patchwork Fri May 25 12:21:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Sahu X-Patchwork-Id: 10427205 X-Patchwork-Delegate: agross@codeaurora.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 09297602D8 for ; Fri, 25 May 2018 12:22:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E038929674 for ; Fri, 25 May 2018 12:22:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D48FE29691; Fri, 25 May 2018 12:22:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1930829674 for ; Fri, 25 May 2018 12:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967002AbeEYMWj (ORCPT ); Fri, 25 May 2018 08:22:39 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48520 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966947AbeEYMWg (ORCPT ); Fri, 25 May 2018 08:22:36 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 0651C60C55; Fri, 25 May 2018 12:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1527250956; bh=vUeZzewOJNQGqi2BW3r9FfD0PyaoQm0Q6QUohnEeIAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gc/IOGN2So8E9ci/06JNNGwZovH9/RMDHKYjtr2AhernTWvyNkIsDKiMBjif/hHbd ZEHm0bi6XXz3Vy74u90/geeo4Im9/BQk3PyC0MT5hq4aPcYoEge9FcFuFYJsRTQZkp ytK61+bsfp/UaidmJ4g3KPb7PCwm+uK+vGAFv+U0= Received: from absahu-linux.qualcomm.com (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: absahu@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4698460117; Fri, 25 May 2018 12:22:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1527250954; bh=vUeZzewOJNQGqi2BW3r9FfD0PyaoQm0Q6QUohnEeIAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f592kFn3iQ+fpCwrQJQa8soHvgM+uz5ivZI6el+V4tgbINMgvXGBBJo/C+ASL2PiK F15KWhdke8rByE5Sl1f+sew9VNUhSnMnY1kdczSKgNsgYqGKsDq1ZQ1BvKHNkjKliR 0rQQpbEWdExYmviU0nf2SCd3ewa/tVHYFFI81RVM= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4698460117 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=absahu@codeaurora.org From: Abhishek Sahu To: Boris Brezillon Cc: David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Miquel Raynal , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, Andy Gross , Archit Taneja , Abhishek Sahu Subject: [PATCH v3 08/16] mtd: rawnand: qcom: erased page detection for uncorrectable errors only Date: Fri, 25 May 2018 17:51:36 +0530 Message-Id: <1527250904-21988-9-git-send-email-absahu@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1527250904-21988-1-git-send-email-absahu@codeaurora.org> References: <1527250904-21988-1-git-send-email-absahu@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Following is the flow in the HW if controller tries to read erased page: 1. First ECC uncorrectable error will be generated from ECC engine since ECC engine first calculates the ECC with all 0xff and match the calculated ECC with ECC code in OOB (which is again all 0xff). 2. After getting ECC error, erased CW detection logic will be applied which is different for BCH and RS ECC a. For BCH, HW checks if all the bytes in page are 0xff and then it updates the status in separate register NAND_ERASED_CW_DETECT_STATUS. b. For RS ECC, the HW reports the same error when reading an erased CW, but it notifies that it is an erased CW by placing special characters at certain offsets in the buffer. So the erased CW detect status should be checked only if ECC engine generated the uncorrectable error. Currently for all other operational errors also (like TIMEOUT, MPU errors, etc.), the erased CW detect logic is being applied so fix this and return EIO for other operational errors. Acked-by: Miquel Raynal Signed-off-by: Abhishek Sahu --- * Changes from v2: 1. Changed commit message slightly * Changes from v1: 1. Added more detail in commit message 2. Added comment before each if/else 3. Removed redundant check for BS_UNCORRECTABLE_BIT drivers/mtd/nand/raw/qcom_nandc.c | 65 ++++++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 22 deletions(-) diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 7f85ef8..9a11827 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -1576,6 +1576,7 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf, struct nand_ecc_ctrl *ecc = &chip->ecc; unsigned int max_bitflips = 0; struct read_stats *buf; + bool flash_op_err = false; int i; buf = (struct read_stats *)nandc->reg_read_buf; @@ -1597,8 +1598,18 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf, buffer = le32_to_cpu(buf->buffer); erased_cw = le32_to_cpu(buf->erased_cw); - if (flash & (FS_OP_ERR | FS_MPU_ERR)) { + /* + * Check ECC failure for each codeword. ECC failure can + * happen in either of the following conditions + * 1. If number of bitflips are greater than ECC engine + * capability. + * 2. If this codeword contains all 0xff for which erased + * codeword detection check will be done. + */ + if ((flash & FS_OP_ERR) && (buffer & BS_UNCORRECTABLE_BIT)) { bool erased; + int ret, ecclen, extraooblen; + void *eccbuf; /* ignore erased codeword errors */ if (host->bch_enabled) { @@ -1616,29 +1627,36 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf, continue; } - if (buffer & BS_UNCORRECTABLE_BIT) { - int ret, ecclen, extraooblen; - void *eccbuf; + eccbuf = oob_buf ? oob_buf + oob_len : NULL; + ecclen = oob_buf ? host->ecc_bytes_hw : 0; + extraooblen = oob_buf ? oob_len : 0; - eccbuf = oob_buf ? oob_buf + oob_len : NULL; - ecclen = oob_buf ? host->ecc_bytes_hw : 0; - extraooblen = oob_buf ? oob_len : 0; - - /* - * make sure it isn't an erased page reported - * as not-erased by HW because of a few bitflips - */ - ret = nand_check_erased_ecc_chunk(data_buf, - data_len, eccbuf, ecclen, oob_buf, - extraooblen, ecc->strength); - if (ret < 0) { - mtd->ecc_stats.failed++; - } else { - mtd->ecc_stats.corrected += ret; - max_bitflips = - max_t(unsigned int, max_bitflips, ret); - } + /* + * make sure it isn't an erased page reported + * as not-erased by HW because of a few bitflips + */ + ret = nand_check_erased_ecc_chunk(data_buf, + data_len, eccbuf, ecclen, oob_buf, + extraooblen, ecc->strength); + if (ret < 0) { + mtd->ecc_stats.failed++; + } else { + mtd->ecc_stats.corrected += ret; + max_bitflips = + max_t(unsigned int, max_bitflips, ret); } + /* + * Check if MPU or any other operational error (timeout, + * device failure, etc.) happened for this codeword and + * make flash_op_err true. If flash_op_err is set, then + * EIO will be returned for page read. + */ + } else if (flash & (FS_OP_ERR | FS_MPU_ERR)) { + flash_op_err = true; + /* + * No ECC or operational errors happened. Check the number of + * bits corrected and update the ecc_stats.corrected. + */ } else { unsigned int stat; @@ -1652,6 +1670,9 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf, oob_buf += oob_len + ecc->bytes; } + if (flash_op_err) + return -EIO; + return max_bitflips; }