From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51722C54E8D for ; Mon, 11 May 2020 16:43:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2FEBF206D9 for ; Mon, 11 May 2020 16:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730684AbgEKQni convert rfc822-to-8bit (ORCPT ); Mon, 11 May 2020 12:43:38 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:42981 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729463AbgEKQni (ORCPT ); Mon, 11 May 2020 12:43:38 -0400 Received: from xps13 (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 5F4CC200003; Mon, 11 May 2020 16:43:34 +0000 (UTC) Date: Mon, 11 May 2020 18:43:33 +0200 From: Miquel Raynal To: =?UTF-8?B?w4FsdmFybyBGZXJuw6FuZGV6?= Rojas Cc: computersforpeace@gmail.com, kdasu.kdev@gmail.com, richard@nod.at, vigneshr@ti.com, sumit.semwal@linaro.org, linux-mtd@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Subject: Re: [PATCH v2] nand: brcmnand: correctly verify erased pages Message-ID: <20200511184333.20d5a560@xps13> In-Reply-To: <20200505082055.2843847-1-noltari@gmail.com> References: <20200504092943.2739784-1-noltari@gmail.com> <20200505082055.2843847-1-noltari@gmail.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Álvaro, Álvaro Fernández Rojas wrote on Tue, 5 May 2020 10:20:55 +0200: > The current code checks that the whole OOB area is erased. > This is a problem when JFFS2 cleanmarkers are added to the OOB, since it will > fail due to the usable OOB bytes not being 0xff. > Correct this by only checking that the ECC aren't 0xff. > > Fixes: 02b88eea9f9c ("mtd: brcmnand: Add check for erased page bitflips") > This extra space between the Fixes tag and your SoB should be removed > Signed-off-by: Álvaro Fernández Rojas > --- > v2: Add Fixes tag > > drivers/mtd/nand/raw/brcmnand/brcmnand.c | 22 ++++++++++++++++++---- > 1 file changed, 18 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c > index e4e3ceeac38f..546f0807b887 100644 > --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c > +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c > @@ -2018,6 +2018,7 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip, > static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd, > struct nand_chip *chip, void *buf, u64 addr) > { > + struct mtd_oob_region oobecc; > int i, sas; > void *oob = chip->oob_poi; > int bitflips = 0; > @@ -2035,11 +2036,24 @@ static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd, > if (ret) > return ret; > > - for (i = 0; i < chip->ecc.steps; i++, oob += sas) { > + for (i = 0; i < chip->ecc.steps; i++) { > ecc_chunk = buf + chip->ecc.size * i; > - ret = nand_check_erased_ecc_chunk(ecc_chunk, > - chip->ecc.size, > - oob, sas, NULL, 0, > + > + ret = nand_check_erased_ecc_chunk(ecc_chunk, chip->ecc.size, > + NULL, 0, NULL, 0, > + chip->ecc.strength); > + if (ret < 0) > + return ret; > + > + bitflips = max(bitflips, ret); > + } > + > + for (i = 0; mtd->ooblayout->ecc(mtd, i, &oobecc) != -ERANGE; i++) > + { > + ret = nand_check_erased_ecc_chunk(NULL, 0, > + oob + oobecc.offset, > + oobecc.length, > + NULL, 0, > chip->ecc.strength); > if (ret < 0) > return If I understand correctly, the cleanmarker is in the "available OOB area", which is somewhere in the OOB area between the bad block marker and the ECC bytes. I think that checking the data buffer and the ECC area only is enough and we can probably leave the remaining spare OOB area. But instead of calling nand_check_erased_ecc_chunk twice, just call: nand_check_erased_ecc_chunk(data, datalen, ecc, ecclen, NULL, 0, strength); And also please clarify your commit log: you are not "just checking the ECC bytes" but you are checking both the main area and the ECC bytes. Thanks, Miquèl