From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BF69322259F; Thu, 11 Dec 2025 01:48:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765417707; cv=none; b=jCyHBikjKOuuiQotulBHtvAQAqrj6C3kivyvXCFauaeE7sQwbk5hTfPh7HLnxrhk6keg+DpP5lGIR4klB1Oy+iP4UHv291WIuDJHdo3F87++2LBCRQan0/1xWJXuthsrTLvrPOHXttT67c5JJ6Sof7rUEN/dkCV3LxRT2C9waeg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765417707; c=relaxed/simple; bh=bsNHK4wRv0LhzVOGuJzCuJXVaLyhXJunj4croYtEeWA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GHdlToDKTJiI0Xnb/lEbEinP0nHX4GMHahRyPZW3f4XVD0lYf3b7pjaL1qQyt6s+CI/GfTwNKQOTpWdo7so1KWxFsjww/Lk4a4HfYhSaXgGeWbwrIt5q4zmBLr0fvb9oRzA3SJu1iNW48o7UGRQ7kQhyXp9U8y37zMOGw7gjBiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lm7a7I7m; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lm7a7I7m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27A6EC4CEF1; Thu, 11 Dec 2025 01:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765417707; bh=bsNHK4wRv0LhzVOGuJzCuJXVaLyhXJunj4croYtEeWA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lm7a7I7mE9qT7WGiGUx8UdxDcVZSa9UN0nSaP4kBdo+g4JvLCTiRlTJ5N6u2XpsaI 3H/0he3VN4xfMWgfLDlRSC/2ZPWMELjtV4Sb7JUvQTeZPJ83sfDsCKUJdU0/s8ugnU FuJJLcqRqY7PjJSOvqVH9+Tn3skjW5GMcqX0jGbLIqtTEUTLBR+HnFLJenNTJF/elA RqNAVSBRTtql7F3quGz3ZEWZCy9kkTvjGzJk/eCcGWdjcY1uuXH3evh9/l+gq2HBsa inrR6e+d4Oolyqn7mBvKmiLACb/xVnlrG3mSlQQzCc423uLgjGHDQJ7eqscGN/9Xz6 xs82Ied/wIB1A== Received: by finisterre.sirena.org.uk (Postfix, from userid 1000) id 0045E1ACB974; Thu, 11 Dec 2025 01:48:24 +0000 (GMT) Date: Thu, 11 Dec 2025 10:48:24 +0900 From: Mark Brown To: James Calligeros Cc: Liam Girdwood , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Kuninori Morimoto , Shengjiu Wang , Jaroslav Kysela , Takashi Iwai , Shenghao Ding , Kevin Lu , Baojun Xu , linux-sound@vger.kernel.org, devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, asahi@lists.linux.dev Subject: Re: [PATCH 4/7] ASoC: soc-dai: define TDM idle behaviour modes Message-ID: References: <20251209-tdm-idle-slots-v1-0-38dabf6bc01e@gmail.com> <20251209-tdm-idle-slots-v1-4-38dabf6bc01e@gmail.com> Precedence: bulk X-Mailing-List: devicetree@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="Pb1joisuHwCHeqND" Content-Disposition: inline In-Reply-To: X-Cookie: It's clever, but is it art? --Pb1joisuHwCHeqND Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 10, 2025 at 01:57:50PM +1000, James Calligeros wrote: > We have the use case where a codec enjoys exclusive use of a bus. For > these, the codec can transmit 0 on any unused slots to hold the bus. > We also have the case where multiple codecs share a single bus. One > codec can weakly pull the bus low when it's not being actively driven by > any of the attached codecs. Or configure so you don't have any idle slots. > However, a number of machines split six codecs into groups of three > across two electrical lines and then OR them at the receiving > port such that they appear on a single bus at the SoC. Because the two > data lines are ORed at the receiver, we have to guarantee that line B is > zero while line A is active, and vice versa. To do this, we set a single codec > from each group to zero-fill during the active slots of the other group. So this is an actual logical OR gate somewhere rather than a direct electrical connection? It'd be good to have an explanation more like this in the commit messages to make it clearer to users what this is intended to do. --Pb1joisuHwCHeqND Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmk6IuUACgkQJNaLcl1U h9D25wf/UsJQP72iHm3Bx4cCkiOBX1vxvax9DWGQFjRnVyUlib3e81+nEUN9hPUP F1z7hEOJl9VBT8DTHkCF+u69lJqj3VcaLyv4y9p5JRmnn8a752strfvFCbb6u8ut zDAP+3DZ0s7/xaM55dr+dXoUfmde97HiZkk23mwW6Mk1GaVR0eW1Q141j2lMBCzM oy2m9mRNnF0FqYMUhtXJE1X2ZqZJ4M3ATessCDZqG3HLk50nNdZxpYKl3T6J6KpG fYksvE1mvk+Kub9c4I7iZ7rpJk09wOy9JMgL1kDKwKmsjsR5SkxnBBMoy6+r/7nP uvdJYoHVO71HRc47ISk6XHQGduPIIA== =WXvU -----END PGP SIGNATURE----- --Pb1joisuHwCHeqND--