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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 85C97C433E4 for ; Tue, 23 Mar 2021 19:15:25 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 542506191D for ; Tue, 23 Mar 2021 19:15:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 542506191D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 3978F11C; Tue, 23 Mar 2021 20:14:32 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 3978F11C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1616526922; bh=WAE7yCVWty48+8GEPn0cF4r2dUhb45XiXoiZhP7rUNk=; h=Subject:To:References:From:Date:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=rphbY2VnhzQs6d4A6ZUpPgMRI02giqsZ1Y5KxgAFFf5cv49tQifjz/zps47jrP5Tk FW79vkz9ZVPnOkQiXS+xnCLrnjhinPOBPYoDnJe3F3CrAh/qzs45B2GB8TkYAM5eSw iYEK5/hC3XvCin57hq/ds8FALkou5Py0JmNs7dCw= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id B5F26F80257; Tue, 23 Mar 2021 20:14:31 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id A9631F8025F; Tue, 23 Mar 2021 20:14:29 +0100 (CET) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 8C3EAF80155 for ; Tue, 23 Mar 2021 20:14:25 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 8C3EAF80155 IronPort-SDR: Hsvh7H/hYmUI1id0fmjIap3OFTVg4yJcgFFISDgEEZihgsRvgY0oAcTHQnDGrJQt9kqvdTG3er bJ0uCF5F1jbg== X-IronPort-AV: E=McAfee;i="6000,8403,9932"; a="177671201" X-IronPort-AV: E=Sophos;i="5.81,272,1610438400"; d="scan'208";a="177671201" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2021 12:14:21 -0700 IronPort-SDR: LrlxJMmlWHeXpmw4l3JwHxWZYy2E6m+cwtx6PxY3N63PBQoecCG22sZ8zTZW0otLKrYbc7VVWu YtY0ZYP+JNAg== X-IronPort-AV: E=Sophos;i="5.81,272,1610438400"; d="scan'208";a="452277659" Received: from laguitie-mobl.amr.corp.intel.com (HELO [10.252.129.185]) ([10.252.129.185]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2021 12:14:20 -0700 Subject: Re: [PATCH] soundwire: intel: move to auxiliary bus To: Greg KH References: <20210323004325.19727-1-yung-chuan.liao@linux.intel.com> <777b4ca6-0d51-285d-549f-6ef768f2a523@linux.intel.com> From: Pierre-Louis Bossart Message-ID: <35cc8d35-a778-d8b2-bee3-bb53f8a6c51e@linux.intel.com> Date: Tue, 23 Mar 2021 14:14:18 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Cc: alsa-devel@alsa-project.org, vinod.koul@linaro.org, linux-kernel@vger.kernel.org, hui.wang@canonical.com, vkoul@kernel.org, srinivas.kandagatla@linaro.org, sanyog.r.kale@intel.com, Bard Liao , rander.wang@linux.intel.com, bard.liao@intel.com X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On 3/23/21 1:32 PM, Greg KH wrote: > On Tue, Mar 23, 2021 at 01:04:49PM -0500, Pierre-Louis Bossart wrote: >> >>>> Note that the auxiliary bus API has separate init and add steps, which >>>> requires more attention in the error unwinding paths. The main loop >>>> needs to deal with kfree() and auxiliary_device_uninit() for the >>>> current iteration before jumping to the common label which releases >>>> everything allocated in prior iterations. >>> >>> The init/add steps can be moved together in the aux bus code if that >>> makes this usage simpler. Please do that instead. >> >> IIRC the two steps were separated during the auxbus reviews to allow the >> parent to call kfree() on an init failure, and auxiliary_device_uninit() >> afterwards. >> >> https://www.kernel.org/doc/html/latest/driver-api/auxiliary_bus.html#auxiliary-device >> >> With a single auxbus_register(), the parent wouldn't know whether to use >> kfree() or auxiliary_device_uinit() when an error is returned, would it? >> > > It should, you know the difference when you call device_register() vs. > device_initialize()/device_add(), for what to do, right? > > Should be no difference here either :) sorry, not following. with the regular devices, the errors can only happen on the second "add" stage. int device_register(struct device *dev) { device_initialize(dev); return device_add(dev); } that's not what is currently implemented for the auxiliary bus the current flow is ldev = kzalloc(..) some inits ret = auxiliary_device_init(&ldev->auxdev) if (ret < 0) { kfree(ldev); goto err1; } ret = auxiliary_device_add(&ldev->auxdev) if (ret < 0) auxiliary_device_uninit(&ldev->auxdev) goto err2; } ... err2: err1: How would I convert this to ldev = kzalloc(..) some inits ret = auxiliary_device_register() if (ret) { kfree(ldev) or not? unit or not? } IIRC during reviews there was an ask that the parent and name be checked, and that's why the code added the two checks below: int auxiliary_device_init(struct auxiliary_device *auxdev) { struct device *dev = &auxdev->dev; if (!dev->parent) { pr_err("auxiliary_device has a NULL dev->parent\n"); return -EINVAL; } if (!auxdev->name) { pr_err("auxiliary_device has a NULL name\n"); return -EINVAL; } dev->bus = &auxiliary_bus_type; device_initialize(&auxdev->dev); return 0; } does this clarify the sequence?