From patchwork Wed Jun 20 07:27:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Sahu X-Patchwork-Id: 10476625 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 96A7C60230 for ; Wed, 20 Jun 2018 09:01:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87254209CE for ; Wed, 20 Jun 2018 09:01:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7B9FC285D9; Wed, 20 Jun 2018 09:01:58 +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 26E62209CE for ; Wed, 20 Jun 2018 09:01:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932588AbeFTI52 (ORCPT ); Wed, 20 Jun 2018 04:57:28 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:49612 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753709AbeFTIpD (ORCPT ); Wed, 20 Jun 2018 04:45:03 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 99A6C60B83; Wed, 20 Jun 2018 07:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529479713; bh=f1ZuNS+AL96dc3Yu0tDYkuTUIUz22p8bk9WRXfBFcuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F2WoM/dvacd2auHolS9xWvEMsq+9IzwLYhtx6NpoVdTZcXC96okyFw3OAfiVVi6DA IZKh1vPkMKTo2jfsX4wEQyBQ8wmAMZc8eA45IfbwJQnZnk+xPomKyJvi/1Gokmlc78 r/EVqkgG4M1r++H9bFLHGFTXfjtZlMeeSfLeNVq4= 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 618EB60B15; Wed, 20 Jun 2018 07:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529479712; bh=f1ZuNS+AL96dc3Yu0tDYkuTUIUz22p8bk9WRXfBFcuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QUn50H0S/VR8kpaRhthubXYIdqb0hzhbWiBlYnOooQVBCL2HBIVXkJQ+GRgegjLUy OTDbYOu3aj2Dv/gpYyJPbbdG82X+3nl3EFW5Hs2/7GxyO8kUq2XDKkaep58NYLrFnz w+UnTsWY1L4Zj4S94B6m+lYFK3jVyspY7jHt7vCA= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 618EB60B15 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 10/15] mtd: rawnand: qcom: modify write_oob to remove read codeword part Date: Wed, 20 Jun 2018 12:57:37 +0530 Message-Id: <1529479662-4026-11-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 QCOM NAND controller layout protects available OOB data bytes with ECC also so when ecc->write_oob() is being called then it can't update just OOB bytes. Currently, it first reads the last codeword which includes old OOB bytes. Then it updates the old OOB bytes with new ones and then again writes the codeword back. The reading codeword is unnecessary since user is responsible to have these bytes cleared to 0xFF. This patch removes the read part and updates the OOB bytes with data area padded with OxFF. Acked-by: Miquel Raynal Signed-off-by: Abhishek Sahu --- * Changes from v3: NONE * Changes from v2: 1. Changed commit message and comments slightly 2. Changed host->use_ecc assignment place * Changes from v1: NEW CHANGE drivers/mtd/nand/raw/qcom_nandc.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 285b2ad3..28361b5 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2064,11 +2064,9 @@ static int qcom_nandc_write_page_raw(struct mtd_info *mtd, /* * implements ecc->write_oob() * - * the NAND controller cannot write only data or only oob within a codeword, - * since ecc is calculated for the combined codeword. we first copy the - * entire contents for the last codeword(data + oob), replace the old oob - * with the new one in chip->oob_poi, and then write the entire codeword. - * this read-copy-write operation results in a slight performance loss. + * the NAND controller cannot write only data or only OOB within a codeword + * since ECC is calculated for the combined codeword. So update the OOB from + * chip->oob_poi, and pad the data area with OxFF before writing. */ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page) @@ -2081,19 +2079,13 @@ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int ret; host->use_ecc = true; - - clear_bam_transaction(nandc); - ret = copy_last_cw(host, page); - if (ret) - return ret; - - clear_read_regs(nandc); clear_bam_transaction(nandc); /* calculate the data and oob size for the last codeword/step */ data_size = ecc->size - ((ecc->steps - 1) << 2); oob_size = mtd->oobavail; + memset(nandc->data_buffer, 0xff, host->cw_data); /* override new oob content to last codeword */ mtd_ooblayout_get_databytes(mtd, nandc->data_buffer + data_size, oob, 0, mtd->oobavail);