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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 D67DD16256E1 for ; Mon, 30 Jul 2018 16:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96A3120890 for ; Mon, 30 Jul 2018 16:09:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 96A3120890 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=codethink.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729561AbeG3RpT (ORCPT ); Mon, 30 Jul 2018 13:45:19 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:43281 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726668AbeG3RpT (ORCPT ); Mon, 30 Jul 2018 13:45:19 -0400 Received: from [148.252.241.226] (helo=[10.35.4.113]) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1fkAjq-0001J8-Pu; Mon, 30 Jul 2018 17:09:38 +0100 Subject: Re: [PATCH v2 4/4] ALSA: usb-audio: Operate UAC3 Power Domains in PCM callbacks To: Takashi Iwai Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org References: <20180719112215.4219-1-jorge.sanjuan@codethink.co.uk> <20180730092336.18741-1-jorge.sanjuan@codethink.co.uk> <20180730092336.18741-5-jorge.sanjuan@codethink.co.uk> From: Jorge Message-ID: <95e003a2-0cc2-6ce1-b330-0a4fa3643386@codethink.co.uk> Date: Mon, 30 Jul 2018 17:09:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/07/18 14:13, Takashi Iwai wrote: > On Mon, 30 Jul 2018 11:23:36 +0200, > Jorge Sanjuan wrote: >> >> Make use of UAC3 Power Domains associated to an Audio Streaming >> path within the PCM's logic. This means, when there is no audio >> being transferred (pcm is closed), the host will set the Power Domain >> associated to that substream to state D1. When audio is being transferred >> (from hw_params onwards), the Power Domain will be set to D0 state. >> >> This is the way the host lets the device know which Terminal >> is going to be actively used and it is for the device to >> manage its own internal resources on that UAC3 Power Domain. >> >> Note the resume method now sets the Power Domain to D1 state as >> resuming the device doesn't mean audio streaming will occur. > > I guess we need the power state transition to D0 also in prepare > callback. The recovery from suspend doesn't need hw_params call but > just prepare -> trigger. Right! Shouldn't it then be enough to just go to D0 on .prepare? I,e. Move the state transition from .hw_params to .prepare. Jorge > > One could think of implementing into the trigger, but since the > transition needs some delay, prepare callback would be a better > choice, as it seems. > > > thanks, > > Takashi > -- Jorge Sanjuan, Software Engineer Codethink Ltd http://www.codethink.co.uk/ We respect your privacy. See https://www.codethink.co.uk/privacy.html