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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 13B31C07E97 for ; Sat, 3 Jul 2021 17:26:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC90E6192B for ; Sat, 3 Jul 2021 17:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229807AbhGCR2w (ORCPT ); Sat, 3 Jul 2021 13:28:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229649AbhGCR2o (ORCPT ); Sat, 3 Jul 2021 13:28:44 -0400 Received: from mail-oi1-x235.google.com (mail-oi1-x235.google.com [IPv6:2607:f8b0:4864:20::235]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A8E8C061762 for ; Sat, 3 Jul 2021 10:26:10 -0700 (PDT) Received: by mail-oi1-x235.google.com with SMTP id u11so15561097oiv.1 for ; Sat, 03 Jul 2021 10:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ntrdXoUnRsaJbvopMZjndYtHLvb7fmdkPnczq42fWHQ=; b=L9PNt0QIYb09GdqPpUNIgRTIBn8uUQX6k7NVA3DE1XT1xsbtgd/WVMIARyS9HpAtnS 30d3LndMMnzXUWepD+5YsiEIyktXWwgnIcEsVqRyt79CFw3wp+ejkhECwD+rdUU1zBz9 3dF7GmZyfJVbh8TiNiAFwVxZp16mwkS+lCutORJ/KOTY2StSHFawBynJxWqx4HH6G2x8 +jsPix+uZ6ORnfd+xZcs/wfwHEHO3jM+Xgrgx+09wjcrOk2XUsWO8u1g7zqIo2BHRxgG q55+0lenZRxVfKTNyT4FebXDfhExkqptoIEKHCDGjEz/mU2nEHtWYVWHB1afDfaajlAD 11Zw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:cc:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ntrdXoUnRsaJbvopMZjndYtHLvb7fmdkPnczq42fWHQ=; b=Hx71sxCfKf2pxZ4uGAMsfiMQ3WN7KjRTtdyJI7aFW4wnp9iZx1ta0e5YToUlbsA8Wc oWpjZD+r+0pBOlbZTOF5V6GYdJDfYVsGas/szVvzKOIstQjMP6uT2+s2aXOWTPht1zc8 CF8YTSltIIKLwlSBR8M3D/1Y7JWAf/iGkFszKo+fR/4nNJ/9Z0iXbKfKE7LnrPMOSPwj nxdzOw6uReFcPKLKk6z4zXWsBLxzta39XPJEcGxp+AWOxyzOmQcAeqbcGY2et2wlE6DV usVQKF7jFx8gtEHKJRF5xC2Vx6LMd90wrJtqQTUdQ9Lt26uCFOdClAWBM1hHGyG4Qo/+ CVdw== X-Gm-Message-State: AOAM530+FmIrk1Dm4ELeYa01dMH77MaIEpCO8nVm20xr2VLyt170Uun3 18iDW/pHA4G3VGOku81lquo= X-Google-Smtp-Source: ABdhPJwgzhlOdZO7WyJ7Mjyp5s6uc9BM0e6v3VNydi2hmunRH4+jI4CS7fwofWQ3VVqdEww4+19erw== X-Received: by 2002:a05:6808:8a:: with SMTP id s10mr4453972oic.70.1625333169468; Sat, 03 Jul 2021 10:26:09 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id o45sm1350377ota.59.2021.07.03.10.26.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 03 Jul 2021 10:26:08 -0700 (PDT) Sender: Guenter Roeck Subject: Re: [PATCH] mtd: core: handle flashes without OTP gracefully To: Tudor.Ambarus@microchip.com, michael@walle.cc, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Cc: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com References: <20210702093841.32307-1-michael@walle.cc> <9bb2acac-aeb8-d2b2-8df0-9acfd972ec5d@microchip.com> <9F46D75C-D00D-4577-A337-7411049EC7D9@walle.cc> <8da3d84e-dfbf-2030-98b4-148362d22f52@microchip.com> From: Guenter Roeck Message-ID: <2716acf0-fcf1-d2ef-83be-152d0300d687@roeck-us.net> Date: Sat, 3 Jul 2021 10:26:06 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <8da3d84e-dfbf-2030-98b4-148362d22f52@microchip.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/3/21 9:42 AM, Tudor.Ambarus@microchip.com wrote: > On 7/3/21 7:08 PM, Michael Walle wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> Am 3. Juli 2021 11:56:14 MESZ schrieb Tudor.Ambarus@microchip.com: >>> On 7/2/21 12:38 PM, Michael Walle wrote: >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you >>> know the content is safe >>>> >>>> There are flash drivers which registers the OTP callbacks although >>> the >>>> flash doesn't support OTP regions and return -ENODATA for these >>>> callbacks if there is no OTP. If this happens, the probe of the whole >>> >>> why do they register the OTP callback if they don't support OTP? >> >> I don't know. But I certainly won't touch that code :p > > why? :D > >> >> >>>> flash will fail. Fix it by handling the ENODATA return code and skip >>>> the OTP region nvmem setup. >>>> >>>> Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") >>>> Reported-by: Guenter Roeck >>>> Signed-off-by: Michael Walle >>>> --- >>>> drivers/mtd/mtdcore.c | 10 ++++++++-- >>>> 1 file changed, 8 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c >>>> index b5ccd3037788..6881d1423dd6 100644 >>>> --- a/drivers/mtd/mtdcore.c >>>> +++ b/drivers/mtd/mtdcore.c >>>> @@ -880,7 +880,10 @@ static int mtd_otp_nvmem_add(struct mtd_info >>> *mtd) >>>> >>>> if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) { >>>> size = mtd_otp_size(mtd, true); >>>> - if (size < 0) >>>> + /* ENODATA means there is no OTP region */ >>>> + if (size == -ENODATA) >>> >>> If no OTP data, maybe it's more appropriate for the clients to just >>> return a retlen of 0. >> >> you mean already checking ENODATA in mtd_otp_size() and return 0. That would also make the hunk below unnecessary. I'll change it. > > I've thought about: > > diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c > index 54f92d09d9cf..9419b33d7238 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0001.c > +++ b/drivers/mtd/chips/cfi_cmdset_0001.c > @@ -2314,7 +2314,7 @@ static int cfi_intelext_otp_walk(struct mtd_info *mtd, loff_t from, size_t len, > > /* Check that we actually have some OTP registers */ > if (!extp || !(extp->FeatureSupport & 64) || !extp->NumProtectionFields) > - return -ENODATA; > + return 0; > There are various places where this is called, including code returning information to userspace. That means you'd be changing the ABI to userspace which would now suddenly return 0 instead of -ENODATA. Guenter 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=-15.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 0AC54C07E97 for ; Sat, 3 Jul 2021 17:27:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B3A316192B for ; Sat, 3 Jul 2021 17:27:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3A316192B Authentication-Results: mail.kernel.org; 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Sat, 03 Jul 2021 10:26:08 -0700 (PDT) Subject: Re: [PATCH] mtd: core: handle flashes without OTP gracefully To: Tudor.Ambarus@microchip.com, michael@walle.cc, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Cc: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com References: <20210702093841.32307-1-michael@walle.cc> <9bb2acac-aeb8-d2b2-8df0-9acfd972ec5d@microchip.com> <9F46D75C-D00D-4577-A337-7411049EC7D9@walle.cc> <8da3d84e-dfbf-2030-98b4-148362d22f52@microchip.com> From: Guenter Roeck Message-ID: <2716acf0-fcf1-d2ef-83be-152d0300d687@roeck-us.net> Date: Sat, 3 Jul 2021 10:26:06 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <8da3d84e-dfbf-2030-98b4-148362d22f52@microchip.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210703_102611_104414_BB6F66A1 X-CRM114-Status: GOOD ( 23.77 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On 7/3/21 9:42 AM, Tudor.Ambarus@microchip.com wrote: > On 7/3/21 7:08 PM, Michael Walle wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> Am 3. Juli 2021 11:56:14 MESZ schrieb Tudor.Ambarus@microchip.com: >>> On 7/2/21 12:38 PM, Michael Walle wrote: >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you >>> know the content is safe >>>> >>>> There are flash drivers which registers the OTP callbacks although >>> the >>>> flash doesn't support OTP regions and return -ENODATA for these >>>> callbacks if there is no OTP. If this happens, the probe of the whole >>> >>> why do they register the OTP callback if they don't support OTP? >> >> I don't know. But I certainly won't touch that code :p > > why? :D > >> >> >>>> flash will fail. Fix it by handling the ENODATA return code and skip >>>> the OTP region nvmem setup. >>>> >>>> Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") >>>> Reported-by: Guenter Roeck >>>> Signed-off-by: Michael Walle >>>> --- >>>> drivers/mtd/mtdcore.c | 10 ++++++++-- >>>> 1 file changed, 8 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c >>>> index b5ccd3037788..6881d1423dd6 100644 >>>> --- a/drivers/mtd/mtdcore.c >>>> +++ b/drivers/mtd/mtdcore.c >>>> @@ -880,7 +880,10 @@ static int mtd_otp_nvmem_add(struct mtd_info >>> *mtd) >>>> >>>> if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) { >>>> size = mtd_otp_size(mtd, true); >>>> - if (size < 0) >>>> + /* ENODATA means there is no OTP region */ >>>> + if (size == -ENODATA) >>> >>> If no OTP data, maybe it's more appropriate for the clients to just >>> return a retlen of 0. >> >> you mean already checking ENODATA in mtd_otp_size() and return 0. That would also make the hunk below unnecessary. I'll change it. > > I've thought about: > > diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c > index 54f92d09d9cf..9419b33d7238 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0001.c > +++ b/drivers/mtd/chips/cfi_cmdset_0001.c > @@ -2314,7 +2314,7 @@ static int cfi_intelext_otp_walk(struct mtd_info *mtd, loff_t from, size_t len, > > /* Check that we actually have some OTP registers */ > if (!extp || !(extp->FeatureSupport & 64) || !extp->NumProtectionFields) > - return -ENODATA; > + return 0; > There are various places where this is called, including code returning information to userspace. That means you'd be changing the ABI to userspace which would now suddenly return 0 instead of -ENODATA. Guenter ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/