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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 D86FAC7618B for ; Fri, 26 Jul 2019 14:46:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B24EE21852 for ; Fri, 26 Jul 2019 14:46:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387500AbfGZOqg (ORCPT ); Fri, 26 Jul 2019 10:46:36 -0400 Received: from mga02.intel.com ([134.134.136.20]:39132 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728167AbfGZOqf (ORCPT ); Fri, 26 Jul 2019 10:46:35 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jul 2019 07:46:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,311,1559545200"; d="scan'208";a="322056387" Received: from msmall-mobl.amr.corp.intel.com (HELO [10.251.154.62]) ([10.251.154.62]) by orsmga004.jf.intel.com with ESMTP; 26 Jul 2019 07:46:34 -0700 Subject: Re: [alsa-devel] [RFC PATCH 31/40] soundwire: intel: move shutdown() callback and don't export symbol To: Cezary Rojewski Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com, Sanyog Kale References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-32-pierre-louis.bossart@linux.intel.com> <39318aab-b1b4-2cce-c408-792a5cc343dd@intel.com> From: Pierre-Louis Bossart Message-ID: Date: Fri, 26 Jul 2019 09:46:34 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <39318aab-b1b4-2cce-c408-792a5cc343dd@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/26/19 5:38 AM, Cezary Rojewski wrote: > On 2019-07-26 01:40, Pierre-Louis Bossart wrote: >> +void intel_shutdown(struct snd_pcm_substream *substream, >> +            struct snd_soc_dai *dai) >> +{ >> +    struct sdw_cdns_dma_data *dma; >> + >> +    dma = snd_soc_dai_get_dma_data(dai, substream); >> +    if (!dma) >> +        return; >> + >> +    snd_soc_dai_set_dma_data(dai, substream, NULL); >> +    kfree(dma); >> +} > > Correct me if I'm wrong, but do we really need to _get_dma_ here? > _set_dma_ seems bulletproof, same for kfree. I must admit I have no idea why we have a reference to DMAs here, this looks like an abuse to store a dai-specific context, and the initial test looks like copy-paste to detect invalid configs, as done in other callbacks. Vinod and Sanyog might have more history than me here.