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=-1.0 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 A8AFCC43387 for ; Fri, 4 Jan 2019 17:13:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A8C6204FD for ; Fri, 4 Jan 2019 17:13:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727753AbfADRNb (ORCPT ); Fri, 4 Jan 2019 12:13:31 -0500 Received: from mga05.intel.com ([192.55.52.43]:50027 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726344AbfADRNb (ORCPT ); Fri, 4 Jan 2019 12:13:31 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Jan 2019 09:13:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,439,1539673200"; d="scan'208";a="123320891" Received: from lwozniak-mobl.amr.corp.intel.com (HELO [10.254.50.87]) ([10.254.50.87]) by FMSMGA003.fm.intel.com with ESMTP; 04 Jan 2019 09:13:29 -0800 Subject: Re: [alsa-devel] ALSA:usb audio Higher sample rates on usb audio no longer working. To: "Gopal, Saranya" , Takashi Iwai , Con Kolivas Cc: "alsa-devel@alsa-project.org" , "linux-usb@vger.kernel.org" , linux-kernel , "felipe.balbi@linux.intel.com" References: <5c7b2c6b-5dcc-7170-f6e1-bf6021bbb72a@linux.intel.com> From: Pierre-Louis Bossart Message-ID: <51872184-3de0-6e69-60e3-c3b4898dcdfa@linux.intel.com> Date: Fri, 4 Jan 2019 11:13:29 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/4/19 10:52 AM, Gopal, Saranya wrote: >>> [ Adding linux-usb ML to Cc, as it's a core USB issue ] >>> >>> So the device seems incorrectly advertising as if it were supporting >>> UAC3 -- assuming the device is still not UAC3-capable. >>> >>> IOW, it's a buggy firmware. We need some blacklisting, or revert the >>> commit for now, unless any real UAC3 device comes up to the market. >> IIRC an UAC3-capable device is required to expose a backwards-compatible >> configuration (either UAC1 or UAC2). Maybe an additional test can be >> done to harden the detection so that UAC3 is only chosen if indeed a >> second audio configuration is present as well. >> >> I also vaguely recall there was talk about adding information in the BOS >> descriptor, but I don't know if this was ever published. >> >> -Pierre > The current detection logic is that UAC3 configuration is chosen only when a device has a configuration with audio interface supporting UAC3 protocol. > Additionally, it already makes sure that UAC3 is selected only when there is more than one configuration. What I meant if that the other configurations are not checked for UAC1 or UAC2 capabilities, you only check that there is more than one configuration