From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (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 212A52907; Thu, 9 May 2024 19:56:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715284577; cv=none; b=nN+6RkMekzLDNvkasmXcQPmWWOAXXPwBsoAFLg38esneDeJ9mF/mMb73byiRa1K90/iq6viydeHGEou+g7fNF25ZCHpbh5wwZbGtJ2FdVA1fXlkIqagXSvcnteGGfBGOyn0s7SLgQNalxL+PLNRUjCIwCdh+bAwqR8FuvV+gYEA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715284577; c=relaxed/simple; bh=yggsdWvGecv9KlZXR7Gn5ZXJpoT8aeY02OM9eHlbgFI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZpcYm13Fdk4Nb9rlZ1LuYGyyuGLmzHEB6A7bItvyo+11icOn6kzIcArUxNYaMppjeqAhGowO20u8kww+ZHeGsrAsgXRDT+tJLTbGL7u8Z1hsGTfLTz+Q1PK54jb1qlkXGLSqp3ngdMaXBYvXFEpI/xHZ5CWt/GS1ouoHjzXWNnI= 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=RTagBD7Q; arc=none smtp.client-ip=192.198.163.16 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="RTagBD7Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715284576; x=1746820576; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=yggsdWvGecv9KlZXR7Gn5ZXJpoT8aeY02OM9eHlbgFI=; b=RTagBD7QGomYEp9Rqj9nG72Ua8Vy5vv2/DsR9AbD09Ee4hJSD0/Vj3Gs XE4JwQT6IKzbCd6jeI/5E4dIYuAWCIJ07g15SF7B0FdiOTVd9Ou8QU1zn C5s72CV9ZF2LQp2oHa4fQao9nlQEIbKQS0KkhEYZsg2UHA7guBjGIAkpJ kRXBM5UEZeLdTAwJXu6qZdhBPhA8axOCAxtr1udmyh2pH80fuy9do3oAe 99RtbaBYIwhoYJ52lTfrnz3JQ2wW9xFdYDodMYQp2Ur9yabwrcGTFmz22 PLjfNntBiYZ2qfMB6TjRJ3YdRBiz4GJ1QMAQ9JuK0ETnYXhV1EUWZ9z3S w==; X-CSE-ConnectionGUID: OVYOC/UESkmsBEEk0xgBww== X-CSE-MsgGUID: UxKGoLOVTd+VGyMPEGcUdA== X-IronPort-AV: E=McAfee;i="6600,9927,11068"; a="11454245" X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="11454245" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 12:56:14 -0700 X-CSE-ConnectionGUID: 0hSRX4lDS5GfwWSqiwJzxQ== X-CSE-MsgGUID: Ld9aKcU1TYSOY0PDBQNl8Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="34213064" Received: from ajunnare-mobl.amr.corp.intel.com (HELO [10.213.181.85]) ([10.213.181.85]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 12:56:11 -0700 Message-ID: <726e7006-30b4-4525-84c8-4fb2ef380994@linux.intel.com> Date: Thu, 9 May 2024 07:54:47 -0500 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v21 09/39] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp To: Wesley Cheng , srinivas.kandagatla@linaro.org, mathias.nyman@intel.com, perex@perex.cz, conor+dt@kernel.org, corbet@lwn.net, lgirdwood@gmail.com, andersson@kernel.org, krzk+dt@kernel.org, gregkh@linuxfoundation.org, Thinh.Nguyen@synopsys.com, broonie@kernel.org, bgoswami@quicinc.com, tiwai@suse.com, bagasdotme@gmail.com, robh@kernel.org, konrad.dybcio@linaro.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: <20240507195116.9464-1-quic_wcheng@quicinc.com> <20240507195116.9464-10-quic_wcheng@quicinc.com> <9bd1ec72-71ea-4a1c-b795-af6e7687ca07@linux.intel.com> <0a4d7c2b-ac7d-7bd4-f97e-db60944a1d39@quicinc.com> Content-Language: en-US From: Pierre-Louis Bossart In-Reply-To: <0a4d7c2b-ac7d-7bd4-f97e-db60944a1d39@quicinc.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit >> Wait, is this saying you will have exactly one PCM device/FE DAI >> connected to the USB BE DAI exposed in patch 11? >> >>> +    SND_SOC_DAPM_MIXER("USB Mixer", SND_SOC_NOPM, 0, 0, >>> +               usb_mixer_controls, >>> +               ARRAY_SIZE(usb_mixer_controls)), >>> + >> >> And then what is the role of the USB mixer if you only have one input? >> >> I must be missing something. >> > > Not sure if this is a QCOM specific implementation, but the way the DT > is defined for the USB offload path is as follows: > >     usb-dai-link { >         link-name = "USB Playback"; > >         cpu { >             sound-dai = <&q6afedai USB_RX>; >         }; > >         codec { >             sound-dai = <&usbdai USB_RX>; >         }; > >         platform { >             sound-dai = <&q6routing>; >         }; >     }; > > Based on our DT parser helper API (qcom_snd_parse_of()) this isn't going > to create a PCM device.  The PCM devices are created for nodes that > don't have a codec and platform defined: > >     mm1-dai-link { >         link-name = "MultiMedia1"; >         cpu { >             sound-dai = <&q6asmdai      MSM_FRONTEND_DAI_MULTIMEDIA1>; >         }; >     }; > > The ASM path is the entity that defines the number of PCM devices that > is created for the QC ASoC platform card, and is where the actual PCM > data is sent over to the DSP.  So there could be several PCM devices > that can use the USB BE DAI. ok, but then how would this work with the ALSA controls reporting which PCM device can be used? I didn't see a mechanism allowing for more than one offloaded device, IIRC the control reported just ONE PCM device number.