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 9F14CC04A68 for ; Sat, 30 Jul 2022 07:55:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230229AbiG3HzF (ORCPT ); Sat, 30 Jul 2022 03:55:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229463AbiG3HzB (ORCPT ); Sat, 30 Jul 2022 03:55:01 -0400 Received: from alexa-out-sd-02.qualcomm.com (alexa-out-sd-02.qualcomm.com [199.106.114.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 478603DF2D; Sat, 30 Jul 2022 00:55:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1659167700; x=1690703700; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=6Shwt+Sz680BwEw6tvfx5LXYNZ3fuh1Or7vfVOJvxiU=; b=DrnOx5CkwaHdq/P887ad3ktO1N/S7xpteCrkYxLbDaXw2QB2t8R6nwL0 Gy9kXWdLz57asjrqh91+SbDj2woSHS5b/jhQaIZhu8rvJtqf24tV4ZOKT bTyIz3Trm5ywbpZzffF1XGj+AM17tRqHgYWU//xs2l/F122LJojWB24Pr U=; Received: from unknown (HELO ironmsg04-sd.qualcomm.com) ([10.53.140.144]) by alexa-out-sd-02.qualcomm.com with ESMTP; 30 Jul 2022 00:55:00 -0700 X-QCInternal: smtphost Received: from unknown (HELO nasanex01a.na.qualcomm.com) ([10.52.223.231]) by ironmsg04-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jul 2022 00:54:59 -0700 Received: from [10.242.58.28] (10.80.80.8) by nasanex01a.na.qualcomm.com (10.52.223.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Sat, 30 Jul 2022 00:54:58 -0700 Message-ID: Date: Sat, 30 Jul 2022 13:24:54 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.0.3 Subject: Re: [PATCH V3] scsi: ufs: Get boot device storage type from command line Content-Language: en-US To: Bart Van Assche CC: , , , Christoph Hellwig References: <1659034814-3473-1-git-send-email-quic_cchinnad@quicinc.com> <77330f3a-5f73-e10f-7e85-f3df304aa4d7@acm.org> From: "Chetan Chinnadagudihundi Ravindranath (Consultant) (QUIC)" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01a.na.qualcomm.com (10.52.223.231) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 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. Thanks, Chetan On 7/30/2022 1:36 AM, Bart Van Assche wrote: > On 7/29/22 05:54, Chetan Chinnadagudihundi Ravindranath (Consultant) > (QUIC) wrote: >> Please suggest any efficient way of making ufs-cmdline part of vmlinux. > > A patch description should not only explain what has been changed but > also why a change is being made. Information about why support is > being added for the androidboot.bootdevice parameter in the Qualcomm > UFS host controller driver is missing from the patch description. > > Please also address Christoph's comment about this new command-line > parameter not being used anywhere in the upstream kernel tree. > > Thanks, > > Bart.