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 BABE580055; Thu, 9 May 2024 19:56:31 +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=1715284593; cv=none; b=A+lWI+DRORlB+mG1mcNnaC5uvesGMKKxonLOmPBn/bdGPfXHcAZvN+SnHQbj+5O4Vns3bOfsqJy+uvr5YskN4T3I/uGUfptP+/37a9DYP6OOATAHbBxLB5zJ8aSmT5NwyDoncUD8ymo5DyntA6/tuuI1m8Al3cHhSGPjCSDobtk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715284593; c=relaxed/simple; bh=+Xg6sg0lsspm+oGIl2gKYWFJ9L1HRkPP8JWiP000C8Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ctXkHb4dgUoe+gXGI7qJvqBVqACriUkUfi4y3254CwCy1zWlNRThlA0KsyEqR3+iSQAqNGTgJaHkdtcXFZl8iJE7CaSVGC4iDHCgfHmqX7UwTb3VDISh7uzm29sg1rLUY1+2OBARzcXnTIoBHj7ReO6Avrve4HN9sA4HIf+cxRw= 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=SepNGnx2; 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="SepNGnx2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715284592; x=1746820592; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=+Xg6sg0lsspm+oGIl2gKYWFJ9L1HRkPP8JWiP000C8Y=; b=SepNGnx2IJcaxT8JIsgqVPN/ggX/nMrhL31NmSKCAZXNPOpCvbozrK0/ xy9sy+LTGx/Eth2dOBVHkGqifhBXpSI7xqHBuBsA7xHdmJFFBlD/OrM1w sK/wTvCe7iXt/ClFo7oFVQEvalqA6dKIf8OcLqot26BOYsis+HQdmsvg7 JXipXuIXdw5axHo6TR4d6N7pbhKSqsuEB1ZJtL3QVIsWF/6DkOEODOyf0 GlRBk54v/0FpzVAM87GAf6SQbvniJN+f5KnxiO7HPNlekYT4QMrrTQfOc yMV3vYMaB7tD2uOrANQAPMluk/2Dde77xtuax1Pq/MN7L/renMAEWEERP w==; X-CSE-ConnectionGUID: SbFtlId8TlKzai7seHk4qw== X-CSE-MsgGUID: Gd1X/7AfS9+Ajo6SxFC6Bw== X-IronPort-AV: E=McAfee;i="6600,9927,11068"; a="11454299" X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="11454299" 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 12:56:32 -0700 X-CSE-ConnectionGUID: 1ox1AHb5TkOlj5+tCcFZIQ== X-CSE-MsgGUID: qXDyMCKMR7Opd+vqjTIr4Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="34213141" 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 12:56:28 -0700 Message-ID: <92abca40-5eda-49d0-bc9d-eeb1a76e3461@linux.intel.com> Date: Thu, 9 May 2024 08:17:39 -0500 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v21 38/39] ASoC: qcom: Populate SoC components string 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> <20240507195116.9464-39-quic_wcheng@quicinc.com> Content-Language: en-US From: Pierre-Louis Bossart In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 5/8/24 15:06, Wesley Cheng wrote: > Hi Pierre, > > On 5/7/2024 2:40 PM, Pierre-Louis Bossart wrote: >> >> >> On 5/7/24 14:51, Wesley Cheng wrote: >>> For userspace to know about certain capabilities of the current platform >>> card, add tags to the components string that it can use to enable >>> support >>> for that audio path.  In case of USB offloading, the "usboffldplybk: >>> 1" tag >> >> usboffloadplayback? >> >> same question as before, do we need spaces? >> > > I think spaces are currently used as a delimiter, so I'll remove the > spaces. > >> And if we have controls, why do we need component strings? The component >> string is not dynamic to the best of my knowledge, this could be >> problematic if the card is no longer capable of supporting this stream, >> while a control can be updated at will. >> > > Maybe I misunderstood your comment here: > > https://lore.kernel.org/linux-usb/925d7c03-c288-49a4-8bcd-395b32810d75@linux.intel.com/ > > At the time, I didn't include the kcontrols on the USB SND portion of > it, which was added after this series.  My interpretation was that there > were userspace entities that could query for general information about > what the card supports based on the components string, or sound card > name.  I treated this as an independent identifier, since the change to > add the offload capable jack was present. My comment at the time stands: it's very hard to figure out that a random card supports USB and is connected to a given endpoint. It'd be much easier as you wrote in the comments on patch 34 to have a control in the "regular" USB card to point to the 'better' offloaded path exposed by another card. Applications wouldn't need to know what this other card is, they would then use the card:device information directly.