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=-0.8 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 49F25C468C6 for ; Thu, 19 Jul 2018 11:56:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F286F20684 for ; Thu, 19 Jul 2018 11:56:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F286F20684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 S1731065AbeGSMjV (ORCPT ); Thu, 19 Jul 2018 08:39:21 -0400 Received: from mx2.suse.de ([195.135.220.15]:35996 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730049AbeGSMjU (ORCPT ); Thu, 19 Jul 2018 08:39:20 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 14859ADAB; Thu, 19 Jul 2018 11:56:31 +0000 (UTC) Date: Thu, 19 Jul 2018 13:56:30 +0200 Message-ID: From: Takashi Iwai To: Jorge Sanjuan Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/4] usb-audio: Add UAC3 Power Domains In-Reply-To: <20180719112215.4219-1-jorge.sanjuan@codethink.co.uk> References: <20180719112215.4219-1-jorge.sanjuan@codethink.co.uk> 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/26 (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=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Jul 2018 13:22:11 +0200, Jorge Sanjuan wrote: > > This patchset add support for UAC3 Power Domains. This feature > of the USB audio class 3 allows the host to notify the device > what it is making use of so power comsumption can be optimized. > > This proposal implements this feature for Power Domains > that include an Input/Output Terminal associated to an > audio Streaming interface. This is the main usage of this > feature according to the spec. For that reason, the logic > for the Power Domain state change has been implemented > within the ALSA PCMs logic and the suspend/resume callbacks > of the usb_driver. The behaviour would be as follows: > > * Power Domain State D0: A Power Domain will reach this state > only when the audio substream associated to that domain is > being used (i,e. Audio playback/capture is happening). > * Power Domain State D1: This is the Idle state where the driver > is going to always want to be in order to reduce power > consumption. > * Power Domain State D2: This state is only set when the usb driver > asumes the device is not going to be used anymore and hence, it > wont care about getting any interrupts from the device. This > will only happen when power level is set to "auto" in sysfs > so the usb driver gets suspended when the interfaces are not in use. > > NOTE: The way this has been implemented will always try to put the > Power Domain in state D1 if the Power Domain exists so there is not a > way a user could disable this feature. It may be worth getting a control > exposed to userland that enables/disables this feature (?). Can it be tied with runtime PM? Need to read through your patchset at first... thanks, Takashi > Power Domains affecting other units independently are required to be > bypassed via a Selector Unit first before the host can change the > power state. This sceneario is not covered in this patchset. > > based on next-20180719 > > Jorge Sanjuan (4): > ALSA: usb-audio: Initial Power Domain support > ALSA: usb-audio: AudioStreaming Power Domain parsing > ALSA: usb-audio: Operate UAC3 Power Domains in PCM callbacks > ALSA: usb-audio: Add UAC3 Power Domains to suspend/resume > > include/linux/usb/audio-v3.h | 4 ++ > sound/usb/Makefile | 1 + > sound/usb/card.c | 9 ++++ > sound/usb/card.h | 2 + > sound/usb/pcm.c | 64 +++++++++++++++++++++-- > sound/usb/pcm.h | 2 + > sound/usb/power.c | 117 +++++++++++++++++++++++++++++++++++++++++++ > sound/usb/power.h | 19 +++++++ > sound/usb/stream.c | 70 +++++++++++++++++++++++--- > 9 files changed, 277 insertions(+), 11 deletions(-) > create mode 100644 sound/usb/power.c > > -- > 2.11.0 >