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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 25CD7C47082 for ; Mon, 7 Jun 2021 06:48:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F0A1611ED for ; Mon, 7 Jun 2021 06:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230254AbhFGGuF (ORCPT ); Mon, 7 Jun 2021 02:50:05 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:51988 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230128AbhFGGuC (ORCPT ); Mon, 7 Jun 2021 02:50:02 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 1576lqB9078633; Mon, 7 Jun 2021 01:47:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1623048472; bh=/egmoX3I90I/Gz07AopX4CzQsPsjx31j/llTXwlpz7k=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=gjgnBH8tml4Bd6Gtid2iJiD+FAUlPT6zRZzAYE38nYEP3rKJ0Stc2zQukVBNMo+Fp 1cT6DEgeohrgO5IvoAKRCT5o/pmAl9LdpfDX5n/WcPkB7rHoAnjdul8vhZr2wR5hzW 8ur05ZF/VudvEuwvqDtbFTVfPip7gCRN/Xc1mRoE= Received: from DFLE104.ent.ti.com (dfle104.ent.ti.com [10.64.6.25]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 1576lq6s056325 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 7 Jun 2021 01:47:52 -0500 Received: from DFLE109.ent.ti.com (10.64.6.30) by DFLE104.ent.ti.com (10.64.6.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 7 Jun 2021 01:47:52 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2 via Frontend Transport; Mon, 7 Jun 2021 01:47:52 -0500 Received: from [10.250.234.148] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 1576ln8D086300; Mon, 7 Jun 2021 01:47:50 -0500 Subject: Re: [PATCH v5 3/5] mtd: spi-nor: otp: return -EROFS if region is read-only To: Michael Walle CC: , , , , , References: <20210604100252.9975-1-michael@walle.cc> <20210604100252.9975-4-michael@walle.cc> <1549db61-500a-e5df-9303-823b41457861@ti.com> <4ba7994b0cc8d436012a776ca14addca@walle.cc> From: Vignesh Raghavendra Message-ID: <3e46bc75-6ace-f7c0-1b14-aae812554ac9@ti.com> Date: Mon, 7 Jun 2021 12:17:48 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <4ba7994b0cc8d436012a776ca14addca@walle.cc> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/7/21 11:38 AM, Michael Walle wrote: > Am 2021-06-07 07:46, schrieb Vignesh Raghavendra: >> On 6/4/21 6:45 PM, Michael Walle wrote: >>> Am 2021-06-04 15:07, schrieb Tudor.Ambarus@microchip.com: >>>> On 6/4/21 1:02 PM, Michael Walle wrote: >>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you >>>>> know the content is safe >>>>> >>>>> SPI NOR flashes will just ignore program commands if the OTP region is >>>>> locked. Thus, a user might not notice that the intended write >>>>> didn't end >>>>> up in the flash. Return -EROFS to the user in this case. From what >>>>> I can >>>>> tell, chips/cfi_cmdset_0001.c also return this error code. >>>>> >>>>> One could optimize spi_nor_mtd_otp_range_is_locked() to read the >>>>> status >>>>> register only once and not for every OTP region, but for that we would >>>>> need some more invasive changes. Given that this is >>>>> one-time-programmable memory and the normal access mode is reading, we >>>>> just live with the small overhead. >>>>> >>>>> Fixes: 069089acf88b ("mtd: spi-nor: add OTP support") >>>>> Signed-off-by: Michael Walle >>>>> Reviewed-by: Pratyush Yadav >>>>> --- >>>>>  drivers/mtd/spi-nor/otp.c | 36 ++++++++++++++++++++++++++++++++++++ >>>>>  1 file changed, 36 insertions(+) >>>>> >>>>> diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c >>>>> index 3898ed67ba1c..063f8fb68649 100644 >>>>> --- a/drivers/mtd/spi-nor/otp.c >>>>> +++ b/drivers/mtd/spi-nor/otp.c >>>>> @@ -249,6 +249,32 @@ static int spi_nor_mtd_otp_info(struct mtd_info >>>>> *mtd, size_t len, >>>>>         return ret; >>>>>  } >>>>> >>>>> +static int spi_nor_mtd_otp_range_is_locked(struct spi_nor *nor, >>>>> loff_t ofs, >>>>> +                                          size_t len) >>>>> +{ >>>>> +       const struct spi_nor_otp_ops *ops = nor->params->otp.ops; >>>>> +       unsigned int region; >>>>> +       int locked; >>>>> + >>>>> +       if (!len) >>>>> +               return 0; >>>>> + >>>> >>>> You won't need this if you put patch 4/5 before this one. With this: >>> >>> This patch will get backported to the stable kernels. Patch 4 on the >>> other hand does not. >>> >> >> I don't see why 4/5 cannot be marked for backport too as it makes 3/5 >> much cleaner? > > What kind of problem does 4/5 fix? I can't see how that patch would > apply to any rule in Documentation/process/stable-kernel-rules.rst. > Looking further, I don't see the need for 4/5 to be a separate patch. Patch 4/5 is simplifying spi_nor_mtd_otp_range_is_locked() by ensuring 'len' passed is never 0 which can be done in 3/5 when introducing spi_nor_mtd_otp_range_is_locked(). So why not squashed it into 3/5. > But sure, adding the same Fixes: tag, I can swap those two. > > -michael