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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 C8EDDC04A6B for ; Mon, 6 May 2019 16:46:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4BFB20578 for ; Mon, 6 May 2019 16:46:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726777AbfEFQqJ (ORCPT ); Mon, 6 May 2019 12:46:09 -0400 Received: from mga17.intel.com ([192.55.52.151]:4605 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726287AbfEFQqJ (ORCPT ); Mon, 6 May 2019 12:46:09 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 May 2019 09:46:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,438,1549958400"; d="scan'208";a="171355585" Received: from linux.intel.com ([10.54.29.200]) by fmsmga001.fm.intel.com with ESMTP; 06 May 2019 09:46:08 -0700 Received: from slaugust-mobl.amr.corp.intel.com (unknown [10.254.21.102]) by linux.intel.com (Postfix) with ESMTP id 8116D58010A; Mon, 6 May 2019 09:46:07 -0700 (PDT) Subject: Re: [alsa-devel] [RFC PATCH 2/7] soundwire: add Slave sysfs support To: Vinod Koul , Greg KH Cc: alsa-devel@alsa-project.org, tiwai@suse.de, linux-kernel@vger.kernel.org, liam.r.girdwood@linux.intel.com, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, joe@perches.com, Sanyog Kale References: <20190504010030.29233-1-pierre-louis.bossart@linux.intel.com> <20190504010030.29233-3-pierre-louis.bossart@linux.intel.com> <20190504065444.GC9770@kroah.com> <20190506151953.GA13178@kroah.com> <20190506162208.GI3845@vkoul-mobl.Dlink> From: Pierre-Louis Bossart Message-ID: Date: Mon, 6 May 2019 11:46:06 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190506162208.GI3845@vkoul-mobl.Dlink> 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 On 5/6/19 11:22 AM, Vinod Koul wrote: > On 06-05-19, 17:19, Greg KH wrote: >> On Mon, May 06, 2019 at 09:42:35AM -0500, Pierre-Louis Bossart wrote: >>>>> + >>>>> +int sdw_sysfs_slave_init(struct sdw_slave *slave) >>>>> +{ >>>>> + struct sdw_slave_sysfs *sysfs; >>>>> + unsigned int src_dpns, sink_dpns, i, j; >>>>> + int err; >>>>> + >>>>> + if (slave->sysfs) { >>>>> + dev_err(&slave->dev, "SDW Slave sysfs is already initialized\n"); >>>>> + err = -EIO; >>>>> + goto err_ret; >>>>> + } >>>>> + >>>>> + sysfs = kzalloc(sizeof(*sysfs), GFP_KERNEL); >>>> >>>> Same question as patch 1, why a new device? >>> >>> yes it's the same open. In this case, the slave devices are defined at a >>> different level so it's also confusing to create a device to represent the >>> slave properties. The code works but I am not sure the initial directions >>> are correct. >> >> You can just make a subdir for your attributes by using the attribute >> group name, if a subdirectory is needed just to keep things a bit more >> organized. > > The key here is 'a subdir' which is not the case here. We did discuss > this in the initial patches for SoundWire which had sysfs :) > > The way MIPI disco spec organized properties, we have dp0 and dpN > properties each of them requires to have a subdir of their own and that > was the reason why I coded it to be creating a device. Vinod, the question was not for dp0 and dpN, it's fine to have subdirectories there, but rather why we need separate devices for the master and slave properties. > > Do we have a better way to handle this? > >> Otherwise, you need to mess with having multiple "types" of struct >> device all associated with the same bus. It is possible, and not that >> hard, but I don't think you are doing that here. >> >> thnaks, >> >> greg k-h >