From patchwork Wed Jun 20 07:27:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Sahu X-Patchwork-Id: 10476581 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 2E69B60383 for ; Wed, 20 Jun 2018 08:56:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1F21F1FE8B for ; Wed, 20 Jun 2018 08:56:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1372021327; Wed, 20 Jun 2018 08:56:54 +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=unavailable 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 DF5C71FE8B for ; Wed, 20 Jun 2018 08:56:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762AbeFTIwN (ORCPT ); Wed, 20 Jun 2018 04:52:13 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:49638 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932863AbeFTIpE (ORCPT ); Wed, 20 Jun 2018 04:45:04 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 405B760B16; Wed, 20 Jun 2018 07:28:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529479702; bh=WS8MxSclPbx+M4a6KfV5x36G2bqbtTeAz98NE/0tK7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=czZ3NqX0Fs3mmVAX6sqveB7CdLxNgXO5EZdnOs1d5Qdgzs3dva+z0loR/G/aruHRa mGlKUha/XEBWU47q3rqInTs5NplQ+5gxk9jOQAMns75AiTMSqxUaRwc2ar+BYUpK0d jd0H47gJ7QHuRw4OpR0C6G58D5kxOvfxr2qU43q0= 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 D152A60B16; Wed, 20 Jun 2018 07:28:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529479701; bh=WS8MxSclPbx+M4a6KfV5x36G2bqbtTeAz98NE/0tK7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dQKlMYaYiaRoPXQ6CR34owj/EC5+KToOiKvn9RUzi1b7Myx03lh+EL6e2WXN2MiNB sKG7/4a91SNKm3tknOHMMV7AbKbceiTEzNJVaZ8Iat08mT1VasrYs/KGawPIePNY6l 49ty8MxgrpV1vTfsXGl6AFNBtHDSrQZl1PKFRsQ4= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D152A60B16 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 , Miquel Raynal Cc: David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, Andy Gross , Archit Taneja , Abhishek Sahu Subject: [PATCH v4 07/15] mtd: rawnand: qcom: erased page detection for uncorrectable errors only Date: Wed, 20 Jun 2018 12:57:34 +0530 Message-Id: <1529479662-4026-8-git-send-email-absahu@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1529479662-4026-1-git-send-email-absahu@codeaurora.org> References: <1529479662-4026-1-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 v3: NONE * 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 fc20149..0d931d5 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; }