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=-2.3 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 E2EA4C3A5A1 for ; Thu, 22 Aug 2019 13:53:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C48A223400 for ; Thu, 22 Aug 2019 13:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731708AbfHVNxL (ORCPT ); Thu, 22 Aug 2019 09:53:11 -0400 Received: from mga07.intel.com ([134.134.136.100]:24281 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731483AbfHVNxL (ORCPT ); Thu, 22 Aug 2019 09:53:11 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Aug 2019 06:53:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,416,1559545200"; d="scan'208";a="203417795" Received: from linux.intel.com ([10.54.29.200]) by fmsmga004.fm.intel.com with ESMTP; 22 Aug 2019 06:53:09 -0700 Received: from tcwomach-mobl1.amr.corp.intel.com (unknown [10.255.34.51]) by linux.intel.com (Postfix) with ESMTP id ABF455803A5; Thu, 22 Aug 2019 06:53:06 -0700 (PDT) Subject: Re: [RFC PATCH 4/5] ASoC: SOF: Intel: hda: add SoundWire stream config/free callbacks To: Guennadi Liakhovetski 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, Bard liao , Rander Wang , Ranjani Sridharan , Liam Girdwood , Jaroslav Kysela , Takashi Iwai , Zhu Yingjiang , YueHaibing , Kai Vehmanen , Arnd Bergmann References: <20190821201720.17768-1-pierre-louis.bossart@linux.intel.com> <20190821201720.17768-5-pierre-louis.bossart@linux.intel.com> <20190822071835.GA30262@ubuntu> From: Pierre-Louis Bossart Message-ID: Date: Thu, 22 Aug 2019 08:53:06 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190822071835.GA30262@ubuntu> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the review Guennadi >> +static int sdw_config_stream(void *arg, void *s, void *dai, >> + void *params, int link_id, int alh_stream_id) > > I realise, that these function prototypes aren't being introduced by these > patches, but just wondering whether such overly generic prototype is really > a good idea here, whether some of those "void *" pointers could be given > real types. The first one could be "struct device *" etc. In this case the 'arg' parameter is actually a private 'struct snd_sof_dev', as shown below [1]. We probably want to keep this relatively opaque, this is a context that doesn't need to be exposed to the SoundWire code. The dai and params are indeed cases where we could use stronger types, they are snd_soc_dai and hw_params respectively. I don't recall why the existing code is this way, Vinod and Sanyog may have the history of this. > >> +{ >> + struct snd_sof_dev *sdev = arg; >> + struct snd_soc_dai *d = dai; [1] >> + struct sof_ipc_dai_config config; >> + struct sof_ipc_reply reply; >> + int ret; >> + u32 size = sizeof(config); >> + >> + memset(&config, 0, size); >> + config.hdr.size = size; >> + config.hdr.cmd = SOF_IPC_GLB_DAI_MSG | SOF_IPC_DAI_CONFIG; >> + config.type = SOF_DAI_INTEL_ALH; >> + config.dai_index = (link_id << 8) | (d->id); >> + config.alh.stream_id = alh_stream_id; > > Entirely up to you, in such cases I usually do something like > > + struct sof_ipc_dai_config config = { > + .type = SOF_DAI_INTEL_ALH, > + .hre = { > + .size = sizeof(config), > + .cmd = SOF_IPC_GLB_DAI_MSG | SOF_IPC_DAI_CONFIG, > + ... > > which then also avoids a memset(). But that's mostly a matter of personal > preference, since this is on stack, the compiler would probably internally > anyway translate the above initialisation to a memset() with all the > following assignments. I have no preference, so in this case I will go with consistency with existing code, which uses the suggested style for all IPCs. > >> + >> + /* send message to DSP */ >> + ret = sof_ipc_tx_message(sdev->ipc, >> + config.hdr.cmd, &config, size, &reply, >> + sizeof(reply)); >> + if (ret < 0) { >> + dev_err(sdev->dev, >> + "error: failed to set DAI hw_params for link %d dai->id %d ALH %d\n", > > Are readers really expected to understand what "dai->id" means? Wouldn't > "DAI ID" be friendlier, although I understand you - who might not know > what "x->y" stands for?.. ;-) I was trying to avoid a confusion here, we have config->dai_index which are shared concepts between topology and firmware, and dai->id which is shared between topology and machine driver (which refers to the dai in the dai_link which has its own .id). In topology files we have the three indices and of course after a couple of weeks I can't recall which one maps to what. I am afraid DAI ID might be confused with dai_index. If there are suggestions on this I am all ears, all I care about is avoiding ambiguity and having to ask Ranjani what index this really is :-)