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=-10.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 60B3BC07E96 for ; Tue, 13 Jul 2021 15:29:38 +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 1CD0061175 for ; Tue, 13 Jul 2021 15:29:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CD0061175 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 A0BD01679; Tue, 13 Jul 2021 17:28:44 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz A0BD01679 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1626190174; bh=Ku80l16oagNS2BsOF+i9JJBUXNx4e7L04/w83UxXH5Y=; h=Subject:To:References:From:Date:In-Reply-To:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=s48dcyrnHxR7sQkoZCs4BgMcqQQ12WJirGgmr0iV6C7lzc08G/2MsPj6ENTK5bNnO tpOkXK47vId0F/rCeBXkeb+c4k1lVfUqSg63uQsyjI6Vh0zybeWcM2NYUI+ZWuHL+F oWQ0OczHyk2QS4b+8+XnVebJ/7G51k6yc0rfiZU0= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id B27D7F80217; Tue, 13 Jul 2021 17:28:43 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 56F09F80229; Tue, 13 Jul 2021 17:28:41 +0200 (CEST) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (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 36BFDF8016A for ; Tue, 13 Jul 2021 17:28:35 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 36BFDF8016A X-IronPort-AV: E=McAfee;i="6200,9189,10044"; a="209999093" X-IronPort-AV: E=Sophos;i="5.84,236,1620716400"; d="scan'208";a="209999093" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2021 08:23:26 -0700 X-IronPort-AV: E=Sophos;i="5.84,236,1620716400"; d="scan'208";a="493853521" Received: from aslawinx-mobl.ger.corp.intel.com (HELO [10.237.180.79]) ([10.237.180.79]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2021 08:23:22 -0700 Subject: Re: [PATCH 02/51] ALSA: core: Add managed card creation To: Takashi Iwai , alsa-devel@alsa-project.org References: <20210713142857.19654-1-tiwai@suse.de> <20210713142857.19654-3-tiwai@suse.de> From: =?UTF-8?Q?Amadeusz_S=c5=82awi=c5=84ski?= Message-ID: <9d6ce40b-101e-5b16-cd6c-8734aea4c4fd@linux.intel.com> Date: Tue, 13 Jul 2021 17:23:02 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210713142857.19654-3-tiwai@suse.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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 7/13/2021 4:28 PM, Takashi Iwai wrote: ... > + > +/** > + * snd_devm_card_new - managed snd_card object creation > + * @parent: the parent device object > + * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] > + * @xid: card identification (ASCII string) > + * @module: top level module for locking > + * @extra_size: allocate this extra size after the main soundcard structure > + * @card_ret: the pointer to store the created card instance > + * > + * This function works like snd_card_new() but manages the allocated resource > + * via devres, i.e. you don't need to free explicitly. > + * > + * When a snd_card object is created with this function and registered via > + * snd_card_register(), the very first devres action to call snd_card_free() > + * is added automatically. In that way, the resource disconnection is assured > + * at first, then released in the expected order. > + */ > +int snd_devm_card_new(struct device *parent, int idx, const char *xid, > + struct module *module, int extra_size, > + struct snd_card **card_ret) > +{ > + struct snd_card *card; > + int err; > + > + *card_ret = NULL; > + if (extra_size < 0) > + extra_size = 0; Maybe just make extra_size unsigned or even better size_t? ... > > /** > * snd_card_ref - Get the card object from the index > @@ -481,6 +547,7 @@ EXPORT_SYMBOL_GPL(snd_card_disconnect_sync); > > static int snd_card_do_free(struct snd_card *card) > { > + card->releasing = true; > #if IS_ENABLED(CONFIG_SND_MIXER_OSS) > if (snd_mixer_oss_notify_callback) > snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE); > @@ -498,7 +565,8 @@ static int snd_card_do_free(struct snd_card *card) > #endif > if (card->release_completion) > complete(card->release_completion); > - kfree(card); > + if (!card->managed) > + kfree(card); > return 0; > } > > @@ -539,6 +607,9 @@ int snd_card_free(struct snd_card *card) > DECLARE_COMPLETION_ONSTACK(released); > int ret; > > + if (card->releasing) > + return 0; > + "card->releasing" use feels bit racy to me... something like below would break it? thread1 thread2 snd_card_free() if(card->releasing) == false thread1 goes sleep snd_card_do_free() card->releasing = true run until the end thread1 resume continues with trying to release > card->release_completion = &released; > ret = snd_card_free_when_closed(card); > if (ret) > @@ -745,6 +816,11 @@ int snd_card_add_dev_attr(struct snd_card *card, > } > EXPORT_SYMBOL_GPL(snd_card_add_dev_attr); > > +static void trigger_card_free(void *data) > +{ > + snd_card_free(data); > +} > + > /** > * snd_card_register - register the soundcard > * @card: soundcard structure > @@ -768,6 +844,15 @@ int snd_card_register(struct snd_card *card) > if (err < 0) > return err; > card->registered = true; > + } else { > + if (card->managed) > + devm_remove_action(card->dev, trigger_card_free, card); Not sure I understand, we are in _register function, so why do we remove action? > + } > + > + if (card->managed) { > + err = devm_add_action(card->dev, trigger_card_free, card); > + if (err < 0) > + return err; > } > > err = snd_device_register_all(card); >