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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43E3EC00144 for ; Mon, 1 Aug 2022 17:28:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232660AbiHAR2G (ORCPT ); Mon, 1 Aug 2022 13:28:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232953AbiHAR1L (ORCPT ); Mon, 1 Aug 2022 13:27:11 -0400 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04DBDEC; Mon, 1 Aug 2022 10:27:10 -0700 (PDT) Received: by mail-pj1-f51.google.com with SMTP id ha11so11544194pjb.2; Mon, 01 Aug 2022 10:27:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc; bh=nr9rJS7HHDAsJ3c3o2JmPMTLZcjCDSrntaUfrab90gA=; b=DqLC0wm3alcPZQWeskhrH5M29+aBsbxsoeH1csTPznatBSrSyD8R12LU50W5HuNiq+ Kw3G8HtPk+gDqwPTl/ppUNCFqCZ3bodGYAQqf2MevMkfsMtEXzOQrs29LAVtcMujnHGI NvWCFQIYv7hV4mEfgNUWtFTHCR4s2dGhRrGGl8GLTiD4rv8V9bAcFXki9pEHfswV05c9 TLJsymrdMg0TALJLueQNhYdI7wk3OXcdN+pStUMG4F7+42VA8NkYP044sTwMhuZfG3yf ixkCQT+xOsnuTO/JMBrraPG+tvSZqY23GRfbPl8oet4aIT8fwL7Lihq3sRI4Gq4QLQ2i wG4A== X-Gm-Message-State: ACgBeo2VCnMk84+lyheBNkE8JqXwo/th1ZngREbgfulmFst29392jY7B ac+98QxUGfhQgPG5xh73F3Qq/3erdSs= X-Google-Smtp-Source: AA6agR46C0GeD25vxGuaYhM5OK0cjGYXueWe4bvmvaPaGfKnwiejdLdxIhaEjh40lkwF8zK/OJ+ISA== X-Received: by 2002:a17:90b:1d10:b0:1f0:76f7:d154 with SMTP id on16-20020a17090b1d1000b001f076f7d154mr21135866pjb.79.1659374829278; Mon, 01 Aug 2022 10:27:09 -0700 (PDT) Received: from ?IPV6:2620:15c:211:201:6496:b2a7:616f:954d? ([2620:15c:211:201:6496:b2a7:616f:954d]) by smtp.gmail.com with ESMTPSA id b12-20020a17090a550c00b001f2fbf2c42esm9185845pji.26.2022.08.01.10.27.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 01 Aug 2022 10:27:07 -0700 (PDT) Message-ID: Date: Mon, 1 Aug 2022 10:27:05 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH V3] scsi: ufs: Get boot device storage type from command line Content-Language: en-US To: "Chetan Chinnadagudihundi Ravindranath (Consultant) (QUIC)" Cc: jejb@linux.ibm.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Christoph Hellwig References: <1659034814-3473-1-git-send-email-quic_cchinnad@quicinc.com> <77330f3a-5f73-e10f-7e85-f3df304aa4d7@acm.org> From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/30/22 00:54, Chetan Chinnadagudihundi Ravindranath (Consultant) (QUIC) wrote: > > why a change is being made: > There are 2 variants of the android bootdev device. One is EMMC and > other is UFS. We would be not knowing the android boot storage type at > build time. So, we need to know the storage type at run time(bootup > time) by reading the  "androidboot.bootdevice=". We need to distinguish > between EMMC and UFS at bootup time and take appropriate action. > > > Information about why support is being added for the > androidboot.bootdevice parameter in the Qualcomm UFS host controller > driver: > > We will get the "androidboot.bootdevice=" by reading cmdline > case 1: if the boot image header version is 3 >         We get the bootdevice info by reading /proc/cmdline ( > __setup("androidboot.bootdevice=", get_android_boot_dev_v3); > > Case 2: if the boot image header version is 4 >         We get the bootdevice info by reading /proc/bootconfig > (android_boot_dev_v4 = xbc_find_value("androidboot.bootdevice", &vnode)) > > Qualcomm UFS modules(ufs-qcom.c) calls this > get_storage_boot_device()(ufs-cmdline.c)   and get the bootdevice info > and take appropriate action. This code is yet to be upstreamed. Please > let me know if this info convincing. Instead of posting the above information on the linux-scsi mailing list, it should be integrated in the description of the patch. Please do that before reposting this patch and also make sure that the code that uses this new kernel command line parameter is included in the same patch series. Thanks, Bart.