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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3FA45C433DF for ; Wed, 24 Jun 2020 17:36:44 +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 C21DE2078A for ; Wed, 24 Jun 2020 17:36:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="a8KWtJlW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C21DE2078A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 43EC21886; Wed, 24 Jun 2020 19:35:52 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 43EC21886 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1593020202; bh=S/QXx04XsY8A68+GrwX49Ddju4hOU4iEBstsCRMeIW8=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=a8KWtJlWTu5qYNEyJDiwUlBV5/ViweGYw7YU9WajIj4Yz7n11kU367n1PbJL5EqB4 fdv1xnC5a1ptpLMmGM+Sno0lb3NWFpes5OubQmC0VC6Xs40scLLOJ5W9M1UgOq34Up mUdG67uNaTZ+x4Im01TggKeELJCRyjmOetENyEhQ= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id D7B4DF8015A; Wed, 24 Jun 2020 19:35:51 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 10C24F8015B; Wed, 24 Jun 2020 19:35:50 +0200 (CEST) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 4437DF80084 for ; Wed, 24 Jun 2020 19:35:47 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 4437DF80084 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8E0D5AE37; Wed, 24 Jun 2020 17:35:46 +0000 (UTC) Date: Wed, 24 Jun 2020 19:35:46 +0200 Message-ID: From: Takashi Iwai To: Jaroslav Kysela Subject: Re: [PATCH] ALSA: core: Warn on empty module In-Reply-To: <6e04386e-d5f7-7e59-3641-13b551de9392@perex.cz> References: <20200624160300.21703-1-tiwai@suse.de> <8d9cd8bf-9023-f3f7-e62d-167da5263714@linux.intel.com> <6e04386e-d5f7-7e59-3641-13b551de9392@perex.cz> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: alsa-devel@alsa-project.org, Mark Brown , Pierre-Louis Bossart 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 Wed, 24 Jun 2020 18:33:00 +0200, Jaroslav Kysela wrote: > > Dne 24. 06. 20 v 18:13 Pierre-Louis Bossart napsal(a): > > > > > > On 6/24/20 11:03 AM, Takashi Iwai wrote: > >> The module argument passed to snd_card_new() must be a valid non-NULL > >> pointer when the module support is enabled. Since ASoC driver passes > >> the argument from each snd_soc_card definition, one may forget to set > >> the owner field and lead to a NULL module easily. > >> > >> For catching such an overlook, add a WARN_ON() in snd_card_new(). > >> Also, put the card->module assignment in the ifdef block for a very > >> minor optimization. > >> > >> Signed-off-by: Takashi Iwai > >> --- > >> sound/core/init.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/sound/core/init.c b/sound/core/init.c > >> index b02a99766351..0478847ba2b8 100644 > >> --- a/sound/core/init.c > >> +++ b/sound/core/init.c > >> @@ -203,7 +203,10 @@ int snd_card_new(struct device *parent, int idx, const char *xid, > >> mutex_unlock(&snd_card_mutex); > >> card->dev = parent; > >> card->number = idx; > >> +#ifdef MODULE > >> + WARN_ON(!module); > >> card->module = module; > >> +#endif > >> INIT_LIST_HEAD(&card->devices); > >> init_rwsem(&card->controls_rwsem); > >> rwlock_init(&card->ctl_files_rwlock); > > > > Would it make sense to also change the ASoC code to use THIS_MODULE > > instead of card->owner? > > > > /* card bind complete so register a sound card */ > > ret = snd_card_new(card->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, > > card->owner, 0, &card->snd_card); > > > > A quick grep shows we are setting .owner = THIS_MODULE pretty much all > > the time for machine drivers. > > > > THIS_MODULE is defined when the object file is created (compile > time). We want to assign the real module which creates the card here, > not "snd_soc_core" which is misleading. Right. We could make a helper macro to pass THIS_MODULE automagically but I don't think it worth. A simple check should suffice. Of course, we can put a similar check in ASoC side, too, so that it points more clearly what's wrong. thanks, Takashi