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 DA577C33CA9 for ; Mon, 13 Jan 2020 15:22:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7437207FD for ; Mon, 13 Jan 2020 15:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729008AbgAMPWS (ORCPT ); Mon, 13 Jan 2020 10:22:18 -0500 Received: from mga01.intel.com ([192.55.52.88]:2225 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727286AbgAMPWR (ORCPT ); Mon, 13 Jan 2020 10:22:17 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Jan 2020 07:22:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,429,1571727600"; d="scan'208";a="304865985" Received: from bcoogan-mobl1.amr.corp.intel.com (HELO [10.252.137.69]) ([10.252.137.69]) by orsmga001.jf.intel.com with ESMTP; 13 Jan 2020 07:22:15 -0800 Subject: Re: [alsa-devel] [PATCH v5 09/17] soundwire: intel: remove platform devices and use 'Master Devices' instead To: Vinod Koul Cc: alsa-devel@alsa-project.org, tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, Ranjani Sridharan , broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Sanyog Kale , Bard liao , Rander Wang References: <20191217210314.20410-1-pierre-louis.bossart@linux.intel.com> <20191217210314.20410-10-pierre-louis.bossart@linux.intel.com> <20191227090826.GM3006@vkoul-mobl> <5be4d9df-0f46-d36f-471c-aae9e1f55cc0@linux.intel.com> <20200106054221.GN2818@vkoul-mobl> <32ae46a7-59ee-4815-270a-a519ff462345@linux.intel.com> <20200110064303.GX2818@vkoul-mobl> <39000dd7-3f77-bc33-0ad3-aa47ba2360f7@linux.intel.com> <20200113051800.GP2818@vkoul-mobl> From: Pierre-Louis Bossart Message-ID: Date: Mon, 13 Jan 2020 09:22:15 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200113051800.GP2818@vkoul-mobl> 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 1/12/20 11:18 PM, Vinod Koul wrote: > On 10-01-20, 10:08, Pierre-Louis Bossart wrote: >> >>>>> The "big" difference is that probe is called by core (asoc) and not by >>>>> driver onto themselves.. IMO that needs to go away. >>>> >>>> What I did is not different from what existed already with platform devices. >>>> They were manually created, weren't they? >>> >>> Manual creation of device based on a requirement is different, did I ask >>> you why you are creating device :) >>> >>> I am simple asking you not to call probe in the driver. If you need >>> that, move it to core! We do not want these kind of things in the >>> drivers... >> >> What core are you talking about? > > soundwire core ofcourse! IMO All that which goes into soundwire-bus-objs is > considered as soundwire core part and rest are drivers intel, qc, so on! This master code was added to the bus: v v soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o and the API is also part of the sdw.h include file. That seems to meet exactly what you describe above, no? git grep sdw_master_device_add (reformatted output) drivers/soundwire/intel_init.c: md = sdw_master_device_add(&intel_sdw_driver, drivers/soundwire/master.c: *sdw_master_device_add(struct sdw_master_driver *driver, drivers/soundwire/master.c: EXPORT_SYMBOL_GPL(sdw_master_device_add); include/linux/soundwire/sdw.h: *sdw_master_device_add(struct sdw_master_driver *driver, So, what exactly is the issue? We are not 'calling the probe in the [Intel] driver' as you state it, we use a SoundWire core API which in turn will create a device. The device core takes care of calling the probe, see the master.c code which is NOT Intel-specific. >> >> The SOF intel driver needs to create a device, which will then be bound with >> a SoundWire master driver. >> >> What I am doing is no different from what your team did with >> platform_register_device, I am really lost on what you are asking. > > Again repeating myself, you call an API to do that is absolutely fine, > but we don't do that in drivers or open code these things That is still quite unclear, what 'open-coding' are you referring to? I am starting to wonder if you missed the addition of the master functionality in the previous patch: [PATCH v5 08/17] soundwire: add initial definitions for sdw_master_device What this patch 9 does is call the core-defined API and implement the intel-specific master driver. > >>>>>> FWIW, the implementation here follows what was suggested for Greybus 'Host >>>>>> Devices' [1] [2], so it's not like I am creating any sort of dangerous >>>>>> precedent. >>>>>> >>>>>> [1] >>>>>> https://elixir.bootlin.com/linux/latest/source/drivers/greybus/es2.c#L1275 >>>>>> [2] https://elixir.bootlin.com/linux/latest/source/drivers/greybus/hd.c#L124 >>>>> >>>>> And if you look closely all this work is done by core not by drivers! >>>>> Drivers _should_ never do all this, it is the job of core to do that for >>>>> you. >>>> >>>> Please look at the code again, you have a USB probe that will manually call >>>> the GreyBus device creation. >>>> >>>> static int ap_probe(struct usb_interface *interface, >>>> const struct usb_device_id *id) >>>> { >>>> hd = gb_hd_create(&es2_driver, &udev->dev, >>>> >>>> >>>> static struct usb_driver es2_ap_driver = { >>>> .name = "es2_ap_driver", >>>> .probe = ap_probe, <<< code above >>>> .disconnect = ap_disconnect, >>>> .id_table = id_table, >>>> .soft_unbind = 1, >>>> }; >>> >>> Look closely the driver es2 calls into greybus core hd.c and gets the >>> work done, subtle but a big differances in the approaches.. >> >> I am sorry, I have absolutely no idea what you are referring to. >> >> The code I copy/pasted here makes no call to the greybus core, it's ap_probe >> -> gb_hd_create. No core involved. If I am mistaken, please show me what I >> got wrong. > > 1. es2_ap_driver is host controller driver > > 2. gb_hd_create() is an API provided by greybus core! same in my code... > > es2 driver doesn't open code creation like you are doing in intel driver, > it doesn't call probe on its own, greybus does that > > This is very common pattern in linux kernel subsytems, drivers dont do > these things, the respective subsystem core does that... see about es2 > driver and implementation of gb_hd_create(). See callers of > platform_register_device() and its implementation. > > I don't know how else I can explain this to you, is something wrong in > how I conveyed this info or you... or something else, I dont know!!! the new 'master' functionality is part of the bus code, so please clarify what you see as problematic for the partition.