From owner-freebsd-multimedia Wed Mar 15 2:39: 4 2000 Delivered-To: freebsd-multimedia@freebsd.org Received: from rina.r.dl.itc.u-tokyo.ac.jp (rina.r.dl.itc.u-tokyo.ac.jp [133.11.199.247]) by hub.freebsd.org (Postfix) with ESMTP id C002C37B919 for ; Wed, 15 Mar 2000 02:38:56 -0800 (PST) (envelope-from tanimura@r.dl.itc.u-tokyo.ac.jp) Received: from rina.r.dl.itc.u-tokyo.ac.jp (tanimura@localhost [127.0.0.1]) by rina.r.dl.itc.u-tokyo.ac.jp (8.9.3+3.2W/3.7W-rina.r-0.1-11.01.2000) with ESMTP/IPv4 id TAA44276; Wed, 15 Mar 2000 19:38:43 +0900 (JST) Date: Wed, 15 Mar 2000 19:38:42 +0900 Message-ID: <14543.26674.980546.81928B@rina> From: Seigo Tanimura To: doconnor@gsoft.com.au Cc: roger@cs.strath.ac.uk, freebsd-multimedia@FreeBSD.ORG, nsayer@quack.kfu.com Subject: Re: Understanding AC97 In-Reply-To: In your message of "Wed, 15 Mar 2000 19:32:31 +1030 (CST)" References: <38CF4B63.5E4A01A3@cs.strath.ac.uk> Cc: Seigo Tanimura User-Agent: Wanderlust/1.0.3 (Notorious) SEMI/1.13.4 (Terai) FLIM/1.12.7 (=?ISO-8859-4?Q?Y=FEzaki?=) MULE XEmacs/21.1 (patch 9) (Canyonlands) (i386--freebsd) Organization: Digital Library Research Division, Information Techinology Centre, The University of Tokyo MIME-Version: 1.0 (generated by SEMI 1.13.4 - "Terai") Content-Type: text/plain; charset=US-ASCII Sender: owner-freebsd-multimedia@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Wed, 15 Mar 2000 19:32:31 +1030 (CST), "Daniel O'Connor" said: Daniel> On 15-Mar-00 Roger Hardiman wrote: >> While AC97 is a standard, you still need >> to know how to setup the chip which interfaces AC97 to your >> ISA or PCI bus. Daniel> So conceviably you could have acbus0: a la miibus0: ? Not sure if the configuration will be like that in the future, but we now drive AC97 in a unified way implemented in sys/dev/sound/pcm/ac97.c. It would be interesting to work out a method to determine if a chip actually accompanies with an AC97 codec or some other one. Certain onboard sound systems have a PCI sound chip and an ISA codec (eg CS461x(PCI)-CS423x(ISA) and NeoMagic 256AV(PCI)-MSS(ISA)) to provide a legacy interface as well. In most cases these ISA codecs are not compatible with AC97, so the drivers need to handle them in a different way. -- Seigo Tanimura To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message