From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20288C433ED for ; Fri, 23 Apr 2021 16:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E64A0613C4 for ; Fri, 23 Apr 2021 16:46:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236900AbhDWQrY (ORCPT ); Fri, 23 Apr 2021 12:47:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:34806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229957AbhDWQrX (ORCPT ); Fri, 23 Apr 2021 12:47:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1783960FE6; Fri, 23 Apr 2021 16:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619196406; bh=hrqrADAEzMFpkpMJhB8rj4N/o1LglX/44krbouGR8yg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=a+sdGTYK4aj9yDFncbICtCZWbqNeYXUw5nC+SdTJCCCyoZqQqXwfDB8l2K7bRr8UY N9rPkMalrUus9Y9lNssS0lW+IZVFqANoT+wr7iCqbGRjpQTsvhjSEfUUYH2T8Dk+q/ Vc9DaR4qdj27qevhjdNdeuEUfyut+yz+SvHrfEp2ga+yla2IpizWu1S9lqpABvVYDw rtvS06aBSxaVeqOsQI9W4SvsqhycdtxdsdWs8Jr03n7PAs/kQ5pPfKlS4pmJasKZW/ UVeXB9zBT81Rwoy/ANVYkarIIqSRRkjyrsORkgVSXFusR4QUf18npK86dcLJHMs+21 UoG0KPu8vhFDA== Date: Fri, 23 Apr 2021 17:46:17 +0100 From: Mark Brown To: Vijendar Mukunda Cc: alsa-devel@alsa-project.org, amistry@google.com, nartemiev@google.com, Alexander.Deucher@amd.com, Basavaraj.Hiregoudar@amd.com, Sunil-kumar.Dommati@amd.com, Jaroslav Kysela , Takashi Iwai , Liam Girdwood , Ranjani Sridharan , Kuninori Morimoto , open list , =?iso-8859-1?Q?P=E9ter?= Ujfalusi Subject: Re: [PATCH 1/2] ASoC: dwc: add a quirk DW_I2S_QUIRK_STOP_ON_SHUTDOWN to dwc driver Message-ID: <20210423164617.GG5507@sirena.org.uk> References: <1619195089-29710-1-git-send-email-Vijendar.Mukunda@amd.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="PpAOPzA3dXsRhoo+" Content-Disposition: inline In-Reply-To: <1619195089-29710-1-git-send-email-Vijendar.Mukunda@amd.com> X-Cookie: This is now. Later is later. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --PpAOPzA3dXsRhoo+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Apr 23, 2021 at 09:54:38PM +0530, Vijendar Mukunda wrote: > For CZ/StoneyRidge platforms, ACP DMA between ACP SRAM and > I2S FIFO should be stopped before stopping I2S Controller DMA. > When DMA is progressing and stop request received, while DMA transfer > ongoing between ACP SRAM and I2S FIFO, Stopping I2S DMA prior to ACP DMA > stop resulting DMA Channel stop failure. This again... copying in Peter for the sequencing discussion. If we need to do this I'm not convinced that bodging it in the driver is a good idea, and especially not deferring it outside of the trigger operation - for example on a suspend or pause we won't actually do a shutdown() so the trigger will end up not happening which seems like it may cause problems. We'd probably be better off with the core knowing what's going on and being able to reorder the callbacks although designing an interface for that seems a bit annoying. > This issue can't be fixed in ACP DMA driver due to design constraint. What is the design constraint here - can't we fix the design? Or is it a hardware design constraint (presumably broken signalling between the I2S and DMA blocks)? --PpAOPzA3dXsRhoo+ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmCC+dkACgkQJNaLcl1U h9BDTgf/e98lodiz8JAhBWlgb4e/N5kUc+JkS6Q8iz5kFGIG96PawL0jUcldx5Wx dml7h0vBjDgBrkgFQ09HQ3nzoyJdVHRa6zqdvCt3af4u2YcpkUb8u7ljoSJJLdDK yXQ4ROt1rC0MKrsVKzHqitiIMo8oSEl2F0Vs4aHLUUof6I3w7qhSSD1VVkGuh36U yJ8JTwaCeKtkXDbth333kbaW7a8biVgUFFprtMzrpoeVH9A9p4CCjH0i+uPwB6cl BX4HoHkoCdzHaisZsNob8MjjykSvoBGVtuKsquEpT+R5PkPRMuGcOYDW1FMJ5FrQ GKwU1bfjUALew8t7yMnnhDZA9SASKg== =025N -----END PGP SIGNATURE----- --PpAOPzA3dXsRhoo+--