From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7F96048EBF6; Mon, 21 Sep 2026 12:07:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789992443; cv=none; b=h4RgpodGfhfH8p53hxd8cG+NyN76AzRDOnZdv+NKQFYl1+F+/4FaTIi0bMkJAoX3KqhXRhAsSTVk6ALkrEjFcOO0IVL303P199zyNEB0f7jBXIjko7vHoVU6OT7XnNJomdjy6/iBh43cQ/G9S2NoqnnRn/5IochoIfRqy18eKJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789992443; c=relaxed/simple; bh=/5Walc3cjaSwroiEzmN8sLMeAmjeoQcDDIqd1wodBC0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VJWvMCY86c4tX4ZBWfDuozs84LY1qcQHBoXyxWAH2uVbL6kpsSDp7VRroD5uLPrJkAWi8Z9SWGTcLsaLBvRfonjp7qptHqWgL8o3jVYhwZcJtpy+AFizmI5FpzrG2SeRYxe/ORp7UYyLB7OgOFS8UnqGG9huL+5BshgfHrcEd4g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SAMPBgRs; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SAMPBgRs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73A651F000FF; Mon, 21 Sep 2026 12:07:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789992442; bh=/5Walc3cjaSwroiEzmN8sLMeAmjeoQcDDIqd1wodBC0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=SAMPBgRsLuE+fu5Qdwu97K7t48iJYOFTrfqGnca8W/N31jyJQau+tyjdEjS7RHbMd lZAi67rbqjDMsT6zg2dZ+/SDEgn3F5nMvOVSNmEYznhpbxOr0eEH31J5DOO9A49Rgf QYVU46CvLtoEEylNKMcjAIBrm6Tf5Ak1sLi1YsNAkkr2Wd2IIl4O3heEDR9yOkQo+j kYu9UbfN9uUotEuRaFVLsOVSZboQsv1UskcGSYSk1cTt7N8ynGkdLG10ztbyRCN2qS ijh3+NAhhprhJRJpwrEPAggnvpjd4DKh7fjrIQpzmsptyU9zC4M4K/biEevx3U+tuX /h1Wz0lXI5c4Q== Date: Mon, 21 Sep 2026 14:07:19 +0200 From: Thierry Reding To: Sheetal Cc: Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , Jonathan Hunter , Sameer Pujar , Kuninori Morimoto , Mohan Kumar , linux-sound@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/3] ASoC: tegra: ASRC control fixes and ratio caching Message-ID: References: <20260921085704.1248920-1-sheetal@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="jhizgarl7ooit75x" Content-Disposition: inline In-Reply-To: <20260921085704.1248920-1-sheetal@nvidia.com> --jhizgarl7ooit75x Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [RFC PATCH 0/3] ASoC: tegra: ASRC control fixes and ratio caching MIME-Version: 1.0 On Mon, Sep 21, 2026 at 08:57:01AM +0000, Sheetal wrote: > This RFC series updates the Tegra186 ASRC driver control handling. >=20 > The main RFC point is the userspace-visible ALSA mixer control ABI > change in patch 2. The existing per-stream controls expose the software > ratio as separate integer and fractional mixer controls. This series > replaces each pair with one two-value mixer control so userspace updates > the integer and fractional parts together. That avoids programming a > transient mixed ratio to hardware, but it does require userspace that > sets ASRC software ratios to switch to the new paired controls. Given the ABI change, do we have a good understanding of who might be using these features? My understanding is that these are used for the setup of hardware pipelines involving sample rate conversions. So these are likely not your regular users that just want to change the volume for headphones and such. This is for highly specific use-cases. Do we know if people use extra userspace software on top of ALSA to set these up, or are they typically dealing with fixed configuration files for specifying these values? So essentially to be able to better understand how to proceed it'd be good to know what the upgrade path is for this. How easy or difficult will it be for people to transition to this? Can we transition them automatically by keeping write-only backwards-compatibility controls that mirror the old ABI and maybe provide a hint that people should be upgrading to the new controls? Since we expect this to also fix the occasional glitch caused by mismatched ratios, I think we really want this, but we need to make sure users aren't left in the dark about such changes and have a reasonable upgrade path. Mark, Liam, do you have any guidelines on how to handle such ABI changes? 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