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 A6567C433FE for ; Tue, 8 Dec 2020 17:05:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6841C23B00 for ; Tue, 8 Dec 2020 17:05:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730540AbgLHRFK (ORCPT ); Tue, 8 Dec 2020 12:05:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:48154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726987AbgLHRFK (ORCPT ); Tue, 8 Dec 2020 12:05:10 -0500 Date: Tue, 8 Dec 2020 17:04:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607447069; bh=4vOM2hPgHrFDdyZpn+0VAXraK8YYeHWHyPRJRhYrL4w=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=IWtshTP78znOhmhQmuNg1rJ+1pqIGQJn7Y9xvGGdIUTkpfMxJnpvs9OHeZGKWX1oX t9k6cy5/I8ug6CyzAKh9eyMQq2L/Gr1VLUxuqOgZOBntDNkbzOyJTxzevadVo9K5c+ oZmg5s9ks23enzfV0ze+jQnhMhy5nHlPzpUSDkCmtp/ahgsFvs1ZjDatiYnccjfJR0 E2K4P42m1vEqnJWeiKob4Fz/mDhy/TuL9xX+A+iEZPYpk3mVbNDtxL/rh57k+hd4uf rYKOLgDMiRIIoFJoSsoLM2iahLJ3EIZif47oVaGwo1LHenXqYHYdVstQdItAfvR59F Xqk80Y6APf4pQ== From: Mark Brown To: Codrin Ciubotariu Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, lgirdwood@gmail.com, tiwai@suse.com, perex@perex.cz, lars@metafoo.de Subject: Re: [RFC PATCH] ASoC: pcm_dmaengine: Add support for BE DAIs Message-ID: <20201208170422.GG6686@sirena.org.uk> References: <20201202085838.1779525-1-codrin.ciubotariu@microchip.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="FwyhczKCDPOVeYh6" Content-Disposition: inline In-Reply-To: <20201202085838.1779525-1-codrin.ciubotariu@microchip.com> X-Cookie: Do not dry clean. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --FwyhczKCDPOVeYh6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 02, 2020 at 10:58:38AM +0200, Codrin Ciubotariu wrote: > This patch is more or less incomplete for the described scenario. This > is because DMAengine's pcm->config is ignored for the BE DAI link, so > runtime->hw is not updated. Also, since pcm_construct/destruct are not > called, the DMA channels are allocated only if DT is used. > Underrun/overrun support would also be a nice to have for the transfers > involving the buffer allocated for the BE. > One way to hold trach of these would be to use a substream_be->runtime > different than the one used for the FE. > Please share your thoughts. I have a hard time getting enthusiastic about this but I think that's more DPCM than anything else. Otherwise this looks sensible as far as it goes. I don't have particular thoughts on exposing errors for the BEs - we could do a dummy PCM, TBH that bodge was used in the past for CODEC<->CODEC links but it's obviously inelegant and messy so I'm not sure it'd help more than just doing something like log the messages in the kernel. It certainly doesn't seem good to introduce anything that is visible to userspace but is DPCM specific. --FwyhczKCDPOVeYh6 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl/PshUACgkQJNaLcl1U h9A3/ggAg1ispHsW7HxfoyKlgiXncZefpDgs4m/UErOav+qf6rSQsHPAz79PrgLW VQoADbxHDWOWuujHLtWZn2TUKLYyj7oX3drpEU3uDuQnNfKGGrN8Q7Pw6jwClZBp mVpxznG0i4F7+6cPw/p51hU/90b//OrVIrfN5IyOLY4BdNNVT3wzQPCBtSinURJ/ 8lwD5WYAerbVldG56JOq28GAEw0cfKOlRyt00eIHcnFS6wuo36T4Gjes5irgmKNe LDyz0pDQX1s/GMb2kfyuDbY88bHXRw/xkc/IPY7QWLfEVTBcyRabJkSekI0jBaSM q8LYqep6dgn3J8/eixPTLyojfNU8JA== =8SdH -----END PGP SIGNATURE----- --FwyhczKCDPOVeYh6--