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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 DF369C5DF63 for ; Wed, 6 Nov 2019 20:15:16 +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 D65D4214D8 for ; Wed, 6 Nov 2019 20:15:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="brH5/Wvj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D65D4214D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 3A5721672; Wed, 6 Nov 2019 20:38:54 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 3A5721672 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1573069184; bh=V61GpYcR2wfiVNGeF169irZYQCmpAgL035T1T3XYAH4=; h=To:References:From:Date:In-Reply-To:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=brH5/WvjXuJRQdFI3Umoa0aRyhPrjh4muBEzE9HsKotVtd7Nj7OqwroFSEY66IEe5 3csnIFjrMJTsx6Li8H5EVhaWc4Ui3GWGL4ITr67+4WTCZbpl8g9TQLdMa4ICkCUsIt jSJcJgQRyB1DoDQq8EQ+RxTqsCCxi+IsSRs6BVQc= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 33CC7F80321; Wed, 6 Nov 2019 20:30:37 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 5950EF800F3; Wed, 6 Nov 2019 20:30:35 +0100 (CET) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 36060F800F3 for ; Wed, 6 Nov 2019 20:30:31 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 36060F800F3 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Nov 2019 11:30:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,275,1569308400"; d="scan'208";a="205931904" Received: from rbidasar-mobl.amr.corp.intel.com (HELO [10.251.0.251]) ([10.251.0.251]) by orsmga006.jf.intel.com with ESMTP; 06 Nov 2019 11:30:27 -0800 To: alsa-devel@alsa-project.org References: <20191022234808.17432-1-pierre-louis.bossart@linux.intel.com> From: Pierre-Louis Bossart Message-ID: Date: Wed, 6 Nov 2019 13:30:27 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20191022234808.17432-1-pierre-louis.bossart@linux.intel.com> Content-Language: en-US Cc: tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, Ranjani Sridharan , vkoul@kernel.org, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Bard liao , Rander Wang Subject: Re: [alsa-devel] [PATCH 0/3] soundwire: use UniqueID only when relevant 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On 10/22/19 6:48 PM, Pierre-Louis Bossart wrote: > The hardware UniqueID, typically enabled with pin-strapping, is > required during enumeration to avoid conflicts between devices of the > same type. > > When there are no devices of the same type, using the UniqueID is > overkill and results in a lot of probe errors due to mismatches > between ACPI tables and hardware capabilities. For example it's not > uncommon for BIOS vendors to copy/paste the same settings between > platforms but the hardware pin-strapping is different. This is > perfectly legit and permitted by MIPI specs. > > With this patchset, the UniqueID is only used when multiple devices of > the same type are detected. The loop to detect multiple identical > devices is not super efficient but with typically fewer than 4 devices > per link there's no real incentive to be smarter. > > This change is only implemented for ACPI platforms, for DeviceTree > there is no change. Vinod, this series has been submitted for review on October 22 and I answered to your questions. There's been no feedback since October 24, so is there any sustained objection here? ACPI platforms are completely unmanageable without this patchset. > > Pierre-Louis Bossart (3): > soundwire: remove bitfield for unique_id, use u8 > soundwire: slave: add helper to extract slave ID > soundwire: ignore uniqueID when irrelevant > > drivers/soundwire/bus.c | 7 +-- > drivers/soundwire/slave.c | 98 +++++++++++++++++++++++++++-------- > include/linux/soundwire/sdw.h | 4 +- > 3 files changed, 84 insertions(+), 25 deletions(-) > _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org https://mailman.alsa-project.org/mailman/listinfo/alsa-devel