[{"id":3683229,"web_url":"http://patchwork.ozlabs.org/comment/3683229/","msgid":"","list_archive_url":null,"date":"2026-04-28T08:06:49","subject":"Re: [PATCH v3] nvmem: core: Default to read-only if wp-gpios present","submitter":{"id":92191,"url":"http://patchwork.ozlabs.org/api/people/92191/","name":"Bartosz Golaszewski","email":"brgl@kernel.org"},"content":"On Mon, 27 Apr 2026 17:19:29 +0200, Marek Vasut said:\n> In case the nvmem DT node contains \"wp-gpios\" DT property, the device\n> currently defaults to read-write and the force_ro sysfs attribute reads\n> 0. Switch to the default read-only, which is both safer, and aligned\n> with eMMC HW BOOT partition force_ro sysfs attribute behavior, which\n> also defaults to read-only.\n>\n> The adjustment of nvmem->read_only value to read-only in case wp-gpios\n> DT property is present must be done only after the device_add() got\n> called because device_add() does internally call nvmem_bin_attr_get_umode(),\n> which configures the permissions of 'nvmem' bin attr based on the value\n> of nvmem->read_only that is only parsed from DT property 'read-only',\n> without any adjustment. This way, if DT property 'read-only' is present,\n> the 'nvmem' attribute is always read-only. Otherwise, if the device is\n> writeable, then 'nvmem' attribute is writeable, and nvmem->read_only\n> defaults to read-only, but can be switched to read-write at runtime via\n> the 'force_ro' attribute.\n\nThis slightly changes the behavior for user-space but I'm willing to give it\na go and see if anyone complains.\n\nReviewed-by: Bartosz Golaszewski \n\nBart","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-i2c@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=VDxq41bk;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; helo=sea.lore.kernel.org;\n envelope-from=linux-i2c+bounces-17191-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org\n header.b=\"VDxq41bk\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=10.30.226.201"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org [172.234.253.10])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g4YFc24kmz1yHX\n\tfor ; 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Tue, 28 Apr 2026\n 01:06:50 -0700 (PDT)","From":"Bartosz Golaszewski ","In-Reply-To":"<20260427152003.26778-1-marex@nabladev.com>","Precedence":"bulk","X-Mailing-List":"linux-i2c@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","References":"<20260427152003.26778-1-marex@nabladev.com>","Date":"Tue, 28 Apr 2026 01:06:49 -0700","X-Gmail-Original-Message-ID":"\n ","X-Gm-Features":"AVHnY4KaOfkQP59M7p91oxim5tZnU_qREt-VIP5EikFBQrbvUZuWOPqd6MgOtQI","Message-ID":"\n ","Subject":"Re: [PATCH v3] nvmem: core: Default to read-only if wp-gpios present","To":"Marek Vasut ","Cc":"Arnd Bergmann , Bartosz Golaszewski ,\n\tGreg Kroah-Hartman ,\n Srinivas Kandagatla ,\n\tlinux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org","Content-Type":"text/plain; charset=\"UTF-8\""}}]