From gd78059@sac.sfbay.sun.com Fri Dec 11 09:46:41 2009 Received: from sunmail6brm.central.sun.com (sunmail6brm.Central.Sun.COM [129.147.4.169]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id nBBHkfVc023467 for ; Fri, 11 Dec 2009 09:46:41 -0800 (PST) Received: from brm-avmta-1.central.sun.com (brm-avmta-1.Central.Sun.COM [129.147.4.11]) by sunmail6brm.central.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.4) with ESMTP id nBBHkf2k013933; Fri, 11 Dec 2009 11:46:41 -0600 (CST) Received: from pmxchannel-daemon.brm-avmta-1.central.sun.com by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) id <0KUI0050T1DTUV00@brm-avmta-1.central.sun.com>; Fri, 11 Dec 2009 10:46:41 -0700 (MST) Received: from dm-sfbay-02.sfbay.sun.com ([129.146.11.31]) by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) with ESMTP id <0KUI000AL1DSBD30@brm-avmta-1.central.sun.com>; Fri, 11 Dec 2009 10:46:40 -0700 (MST) Received: from sac.sfbay.sun.com (sac.SFBay.Sun.COM [129.146.226.132]) by dm-sfbay-02.sfbay.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.4) with ESMTP id nBBHke1s006329; Fri, 11 Dec 2009 09:46:40 -0800 (PST) Received: from sac.sfbay.sun.com (localhost [127.0.0.1]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id nBBHkcuu023462; Fri, 11 Dec 2009 09:46:38 -0800 (PST) Received: (from gd78059@localhost) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8/Submit) id nBBHkcXG023458; Fri, 11 Dec 2009 09:46:38 -0800 (PST) Date: Fri, 11 Dec 2009 09:46:38 -0800 (PST) From: "Garrett D'Amore - sun microsystems" Subject: Decoupling audio device interrupts [PSARC/2009/674 FastTrack timeout 12/18/2009] To: PSARC-ext@sun.com Cc: audio-oss-ext@sun.com Message-id: <200912111746.nBBHkcXG023458@sac.sfbay.sun.com> Content-transfer-encoding: 7BIT X-PMX-Version: 5.4.1.325704 Status: RO Content-Length: 4707 Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI This information is Copyright 2009 Sun Microsystems 1. Introduction 1.1. Project/Component Working Name: Decoupling audio device interrupts 1.2. Name of Document Author/Supplier: Author: Garrett D'Amore 1.3 Date of This Document: 11 December, 2009 4. Technical Description Abstract We propose to move processing of the audio data (that performed by audio_consume() and audio_produce()) from device interrupts to a regular framework internal periodic function. There are changes to the Boomer DDI (PSARC 2008/318) as a result. Detail Historically, the audio framework (both the legacy SADA framework and Boomer) have used device-driven interrupts to drive processing of audio data. While this has worked very well, it turns out that there can be challenges from this as different devices have different interrupt needs, and driving the mixing framework from a device interrupt makes the framework subject to the interrupt requirements of the device. Ultimately, this either prevents, or makes much more difficult, some of the changes we would like to make for virtualization, Sun Ray, and automatic hotplug in the future. It turns out that the nature of audio data is that the streaming data moves at a regular fixed rate. So we are able to drive use a timer-driven event instead of a device specific interrupt to perform our internal audio processing. This also lets us decouple the rate at which the audio framework processes audio data from from any configuration requirements of the device. (There are still some minor requirements... the device must be able to pre-buffer at least enough audio data to cover one and a half periodic intervals, and the device must be able to report its DMA position. Additionally, if the device needs deeper buffering, it must report that to the framework via the audio_engine_playahead(9E) entry point in its audio_engine_ops vector. It turns out that for most devices, we are simply able to remove all hardware interrupt handling, eliminating about 20% of the code complexity for most typical AC'97 drivers. Initially, we are using a ddi_periodic (see ddi_periodic_add) to drive the internal framework. This limits us to a 10 msec granularity/latency. In the future, we might investigate other options to use higher resolution clocking and lower latencies. (The use of ddi_periodic's is a framework internal detail, and not necessarily intrinsic to this case.) DDI Changes The audio_engine_open() entry point in the audio_engine_ops vector is changed to have the following signature: int (*audio_engine_open)(void *state, int flags, uint_t *nframesp, caddr_t *buf); The nframesp argument is new, and is the total number of frames that buf can hold. (It replaces the former nfragsp and fragframesp members, which used to report the individual fragment size and total number of fragments. With this change, the audio framework has no need to know if the engine fragments data into regular blocks, nor any of said details. The framework is totally decoupled from this particular set of device details with this change.) We also have removed the audio_engine_consume() and audio_engine_produce() functions. Device drivers no longer have any need to trigger this functionality. Finally, we have bumped the value AUDIO_ENGINE_VERSION to 2. While the changes to the DDI are only being made to Consolidation Private interfaces, this prevents someone from trying to mix-and-match old devices with the new framework. (Generally they would not load anyway, due to a failure to resolve the audio_engine_produce or audio_engine_consume symbols, but this just makes it absolutely certain.) As with the previous Boomer DDI, these interfaces remain Consolidation Private. Release Binding We are seeking Patch binding for these changes, dependent upon Boomer (PSARC 2008/318). While the Boomer case was integrated with Minor binding, and while we are dependent on Boomer, there is some risk that an actual minor release may be cut with Boomer before this change is integrated. In such an event, we believe it would be approriate for the changes described here to be integrated in a patch to such a release. Note that this case explicitly does _not_ seek to alter the original commitment of Boomer, so it would not be appropriate to deliver this as a patch to a release that did not already have Boomer integrated. (I.e. it would not be appropriate to backport this to Solaris 10.) 6. Resources and Schedule 6.4. Steering Committee requested information 6.4.1. Consolidation C-team Name: ON 6.5. ARC review type: FastTrack 6.6. ARC Exposure: open From Sebastien.Roy@sun.com Wed Dec 16 07:49:53 2009 Received: from sunmail3mpk.sfbay.sun.com (sunmail3mpk.SFBay.Sun.COM [129.146.11.52]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id nBGFnrKT021282 for ; Wed, 16 Dec 2009 07:49:53 -0800 (PST) Received: from brm-avmta-1.central.sun.com (brm-avmta-1.Central.Sun.COM [129.147.4.11]) by sunmail3mpk.sfbay.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.4) with ESMTP id nBGFnpAa006813; Wed, 16 Dec 2009 07:49:52 -0800 (PST) Received: from pmxchannel-daemon.brm-avmta-1.central.sun.com by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) id <0KUR00H0B5B4QH00@brm-avmta-1.central.sun.com>; Wed, 16 Dec 2009 08:49:52 -0700 (MST) Received: from brmea-mail-4.sun.com ([192.18.98.36]) by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) with ESMTP id <0KUR00AVP5B3VX50@brm-avmta-1.central.sun.com>; Wed, 16 Dec 2009 08:49:51 -0700 (MST) Received: from fe-amer-10.sun.com ([192.18.109.80]) by brmea-mail-4.sun.com (8.13.6+Sun/8.12.9) with ESMTP id nBGFnpf3003042; Wed, 16 Dec 2009 15:49:51 +0000 (GMT) Received: from conversion-daemon.mail-amer.sun.com by mail-amer.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) id <0KUR00C003FTOR00@mail-amer.sun.com>; Wed, 16 Dec 2009 08:49:51 -0700 (MST) Received: from [129.148.174.103] ([unknown] [129.148.174.103]) by mail-amer.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) with ESMTPSA id <0KUR000I95AXGQ40@mail-amer.sun.com>; Wed, 16 Dec 2009 08:49:46 -0700 (MST) Date: Wed, 16 Dec 2009 10:46:56 -0500 From: Sebastien Roy Subject: Re: Decoupling audio device interrupts [PSARC/2009/674 FastTrack timeout 12/18/2009] In-reply-to: <200912111746.nBBHkcXG023458@sac.sfbay.sun.com> Sender: Sebastien.Roy@sun.com To: "Garrett D'Amore - sun microsystems" Cc: PSARC-ext@sun.com, audio-oss-ext@sun.com Message-id: <1260978416.17127.34.camel@strat> Organization: Sun Microsystems MIME-version: 1.0 Content-type: text/plain; CHARSET=US-ASCII Content-transfer-encoding: 7BIT X-PMX-Version: 5.4.1.325704 References: <200912111746.nBBHkcXG023458@sac.sfbay.sun.com> Status: RO Content-Length: 413 On Fri, 2009-12-11 at 09:46 -0800, Garrett D'Amore - sun microsystems wrote: > Abstract > > We propose to move processing of the audio data (that performed by > audio_consume() and audio_produce()) from device interrupts to a regular > framework internal periodic function. There are changes to the Boomer DDI > (PSARC 2008/318) as a result. I've reviewed this case and have no issues to bring up. +1 -Seb From gdamore@sun.com Wed Dec 16 10:15:13 2009 Received: from sunmail6brm.central.sun.com (sunmail6brm.Central.Sun.COM [129.147.4.169]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id nBGIFDu6026849 for ; Wed, 16 Dec 2009 10:15:13 -0800 (PST) Received: from nwk-avmta-2.sfbay.sun.com (nwk-avmta-2.SFBay.Sun.COM [129.145.155.6]) by sunmail6brm.central.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.4) with ESMTP id nBGIFAL4027920 for <@sunmail2sca.sfbay.sun.com:PSARC-ext@sun.com>; Wed, 16 Dec 2009 12:15:12 -0600 (CST) Received: from pmxchannel-daemon.nwk-avmta-2.sfbay.sun.com by nwk-avmta-2.sfbay.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) id <0KUR0064BC1CZN00@nwk-avmta-2.sfbay.sun.com> for PSARC-ext@sun.com (ORCPT PSARC-ext@sun.com); Wed, 16 Dec 2009 10:15:12 -0800 (PST) Received: from sca-es-mail-1.sun.com ([192.18.43.132]) by nwk-avmta-2.sfbay.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) with ESMTP id <0KUR00MDYC1BPKC0@nwk-avmta-2.sfbay.sun.com> for PSARC-ext@sun.com (ORCPT PSARC-ext@sun.com); Wed, 16 Dec 2009 10:15:11 -0800 (PST) Received: from fe-sfbay-10.sun.com ([192.18.43.129]) by sca-es-mail-1.sun.com (8.13.7+Sun/8.12.9) with ESMTP id nBGIFBCw000934 for ; Wed, 16 Dec 2009 10:15:11 -0800 (PST) Received: from conversion-daemon.fe-sfbay-10.sun.com by fe-sfbay-10.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) id <0KUR00200AHPJF00@fe-sfbay-10.sun.com> for PSARC-ext@sun.com (ORCPT PSARC-ext@sun.com); Wed, 16 Dec 2009 10:15:11 -0800 (PST) Received: from [192.168.251.11] ([unknown] [76.93.15.33]) by fe-sfbay-10.sun.com (Sun Java(tm) System Messaging Server 7u2-7.04 64bit (built Jul 2 2009)) with ESMTPSA id <0KUR00L9VC118B70@fe-sfbay-10.sun.com> for PSARC-ext@sun.com (ORCPT PSARC-ext@sun.com); Wed, 16 Dec 2009 10:15:02 -0800 (PST) Date: Wed, 16 Dec 2009 10:15:01 -0800 From: "Garrett D'Amore" Subject: PSARC 2009/674 Decoupling audio device interrupts Sender: Garrett.Damore@sun.com To: PSARC-ext Message-id: <4B2923A5.7020501@sun.com> MIME-version: 1.0 Content-type: text/plain; CHARSET=US-ASCII; format=flowed Content-transfer-encoding: 7BIT X-PMX-Version: 5.4.1.325704 User-Agent: Thunderbird 2.0.0.23 (X11/20091013) Status: RO Content-Length: 54 This case was approved at PSARC today. - Garrett