From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A9528210190; Tue, 6 Aug 2024 14:52:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722955932; cv=none; b=eRvbce2f8iwakb24Q/K7eWh7V5oYmQQqpQfucMc9yHCuukCk1BXaTiWrOnpX485GNECTinUG2qC95LAKQZVCdfKkkeptWlXaL5smoQ3ZeCyUWnYcWT+jr50V+FoBi75z0A/jDT0cPAk4z27dKxbvuBola0I1Wpc6lZGdlFWl2EU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722955932; c=relaxed/simple; bh=ulhVGtEPKBdoyHz0l9ezBsABeAF4IDtYxjCyDs4xjzE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XviYqBpEJvm4l8ff3L2XWSic1RNMr2es3gMaBlFwZLiN6w9+Z2ocYCYG7qC1kC3OGq8mXHSPRAB1h2hMfA3Dt8KOS+5dE76TAcx+u0W4+4L9z8oFLnsca+RuCtcgyj3JbTX1XR0+op7+0hTV14luUA9ikIREV4YM+lxwpJvdz7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=J1gyXILH; arc=none smtp.client-ip=198.175.65.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="J1gyXILH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1722955931; x=1754491931; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=ulhVGtEPKBdoyHz0l9ezBsABeAF4IDtYxjCyDs4xjzE=; b=J1gyXILH5Hy10QTy9+i/v3C0PFMbwIUuS7p57nJgtIY3aDySErih81eT upW9yEk+EFmh1PSBgibaBU0wfjhO34P3Tn6ijprxtG9iXhdk5529XTsbT /x4O/FXRWR4T4Nqsm3tCFybLyV6lzTGtGi4r0LO7qb+PtSrMNmy3q/J+1 6VIdTdTiQPn36Wq0hva4xvy3711++wkukvqy1QjSrxp7Haroymc8M9Ary +3jU/kq7gCRHdCS6L/EYS+o7bEVPjQdBidBJNl2BOexVPjpa4IRy6ck1J y4GLJzFSFWdweqwoHP2q+04tUg+d5RaByRDlA/EE1ZWPVvWI5Mfyy8pLm g==; X-CSE-ConnectionGUID: LLunlwrKQGuc4zUy7GuwDQ== X-CSE-MsgGUID: mbhwuqlZRjW6sGIJMtR95w== X-IronPort-AV: E=McAfee;i="6700,10204,11156"; a="21102049" X-IronPort-AV: E=Sophos;i="6.09,268,1716274800"; d="scan'208";a="21102049" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2024 07:52:03 -0700 X-CSE-ConnectionGUID: cJPN9FP4TuWrzG0YHOubYw== X-CSE-MsgGUID: Y9MkFWawRqaVopuvdK1S7w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,268,1716274800"; d="scan'208";a="87476718" Received: from aslawinx-mobl.ger.corp.intel.com (HELO [10.94.0.53]) ([10.94.0.53]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2024 07:51:57 -0700 Message-ID: <186ae30f-678c-423a-a56f-74510a184f99@linux.intel.com> Date: Tue, 6 Aug 2024 16:51:57 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v24 23/34] ALSA: usb-audio: Prevent starting of audio stream if in use Content-Language: en-US To: Wesley Cheng , srinivas.kandagatla@linaro.org, mathias.nyman@intel.com, perex@perex.cz, conor+dt@kernel.org, corbet@lwn.net, broonie@kernel.org, lgirdwood@gmail.com, krzk+dt@kernel.org, Thinh.Nguyen@synopsys.com, bgoswami@quicinc.com, tiwai@suse.com, gregkh@linuxfoundation.org, robh@kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-sound@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-doc@vger.kernel.org, alsa-devel@alsa-project.org References: <20240801011730.4797-1-quic_wcheng@quicinc.com> <20240801011730.4797-24-quic_wcheng@quicinc.com> From: =?UTF-8?Q?Amadeusz_S=C5=82awi=C5=84ski?= In-Reply-To: <20240801011730.4797-24-quic_wcheng@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/1/2024 3:17 AM, Wesley Cheng wrote: > With USB audio offloading, an audio session is started from the ASoC > platform sound card and PCM devices. Likewise, the USB SND path is still > readily available for use, in case the non-offload path is desired. In > order to prevent the two entities from attempting to use the USB bus, > introduce a flag that determines when either paths are in use. > How can this happen? Can you provide some example with list of devices and which one should block the other? If I recall correctly devices are already exclusive unless you support substreams which ASoC does not at the moment.