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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3FD69C47082 for ; Mon, 7 Jun 2021 06:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28EF360C3F for ; Mon, 7 Jun 2021 06:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230215AbhFGGKv (ORCPT ); Mon, 7 Jun 2021 02:10:51 -0400 Received: from ssl.serverraum.org ([176.9.125.105]:41249 "EHLO ssl.serverraum.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230203AbhFGGKu (ORCPT ); Mon, 7 Jun 2021 02:10:50 -0400 Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id A95F322172; Mon, 7 Jun 2021 08:08:56 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1623046137; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DzuWySf29iNNVaJeQVLK8ftx+fbfOMCdpAMGH60BRJY=; b=v6fteIE6JrovjRlc372f+PAaq6l6ffqlKryJOv8kigSsoen+hGv8D62fCjULu0BUFz/CBM zv1ldaTEA+1QE00H0phE3V3sImfoWsN0ndZyvm0AEH19ZBkw/sBmIYtCTWY6YHh+UMbHP7 Bevb4FQD7vDAC4gOzpd9IjqdVylQb8M= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Mon, 07 Jun 2021 08:08:56 +0200 From: Michael Walle To: Vignesh Raghavendra Cc: Tudor.Ambarus@microchip.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, p.yadav@ti.com, miquel.raynal@bootlin.com, richard@nod.at Subject: Re: [PATCH v5 3/5] mtd: spi-nor: otp: return -EROFS if region is read-only In-Reply-To: <1549db61-500a-e5df-9303-823b41457861@ti.com> References: <20210604100252.9975-1-michael@walle.cc> <20210604100252.9975-4-michael@walle.cc> <1549db61-500a-e5df-9303-823b41457861@ti.com> User-Agent: Roundcube Webmail/1.4.11 Message-ID: <4ba7994b0cc8d436012a776ca14addca@walle.cc> X-Sender: michael@walle.cc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. But sure, adding the same Fixes: tag, I can swap those two. -michael