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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 833B6C433ED for ; Mon, 19 Apr 2021 07:16:28 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7706E610A1 for ; Mon, 19 Apr 2021 07:16:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7706E610A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id B1CE516B2; Mon, 19 Apr 2021 09:15:35 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz B1CE516B2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1618816585; bh=LKoEq95jiSMlqGLX9/l2GQvT739mgwD3+OEYWzvX2fU=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=rEinocyVi9XaDFupo7kOjwsNxZmdh7S1B25pMX+gcMw2SqnK9PHWp8TJWhJjSa86M NX3PCv6zr++b+oBRusYCPHJGn/MOkki8EGr/gUVElmE6oHCnQ4JPIpWyONFgfStBIM UsIrKYWKxB1yhrzJO5y+gNoSK9lvJzLR2H03iYBk= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 29963F80164; Mon, 19 Apr 2021 09:15:35 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 720E5F80227; Mon, 19 Apr 2021 09:15:33 +0200 (CEST) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id BFE37F80164 for ; Mon, 19 Apr 2021 09:15:20 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz BFE37F80164 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A6E28AD4A; Mon, 19 Apr 2021 07:15:20 +0000 (UTC) Date: Mon, 19 Apr 2021 09:15:20 +0200 Message-ID: From: Takashi Iwai To: Geraldo Nascimento Subject: Re: [PATCH v2] Pioneer devices: engage implicit feedback sync for playback In-Reply-To: References: <20210409110745.kbr5z2jinsaur2ac@base.nu> <20210417222630.dpqju7bowvks5nnq@base.nu> <20210418124301.scwvjqxwanlarko6@base.nu> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: alsa-devel@alsa-project.org, Olivia Mackintosh X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Sun, 18 Apr 2021 16:16:56 +0200, Geraldo Nascimento wrote: > > Em Dom, 18 de abr de 2021 09:45, Olivia Mackintosh escreveu: > > > As a blind shot: might the stall be avoided by passing the recently > > introduced chip->playback_first flag?  The revised patch is below. > > This appears to fix the issue, thank you! I am curious as to why this is > not required for Geraldo's DDJ-SR2. > > Heh, sometimes I think Takashi Iwai is psychic ;-) Heh, it was our luck that we've worked on the similar problem very recently. > Just kidding, he's "just" very talented and very experienced. Anyway, the > DDJ-SR2 is originally a Serato controller. It still requires two MIDI SysEx > messages to unmute the RCA inputs - engaging "Serato Mode" in marketing-speak. > > My point is that Pioneer may be a little more compliant / a little less > deviant from the UAC2 standard when designing gear for use with third-party > software. I think many devices require the implicit feedback seem following this pattern: for such devices, the full-duplex streams are mandatory, i.e. both streams have to be started always. And the implicit feedback is triggered at the later point for a proper sync. > My initial thought was that certain devices that restrict capture unless > regular SysEx/Control URBs are sent may mean that Playback first support > is required (e.g. 750, 850, 450). Please correct me if this intuition is > incorrect. As mentioned previously, it might be the difference of the PCM parameters to be deployed. I guess Geraldo didn't test speaker-test program but maybe only the standard sound backends like JACK, etc. In anyway, I'm going to format and submit the proper patch for merging. thanks, Takashi