1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
598 lines
14 KiB
XML
598 lines
14 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
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<book id="ViaAudioGuide">
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<bookinfo>
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<title>Via 686 Audio Driver for Linux</title>
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<authorgroup>
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<author>
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<firstname>Jeff</firstname>
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<surname>Garzik</surname>
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</author>
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</authorgroup>
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<copyright>
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<year>1999-2001</year>
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<holder>Jeff Garzik</holder>
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</copyright>
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<legalnotice>
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<para>
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This documentation is free software; you can redistribute
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it and/or modify it under the terms of the GNU General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later
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version.
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</para>
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<para>
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This program is distributed in the hope that it will be
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useful, but WITHOUT ANY WARRANTY; without even the implied
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warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the GNU General Public License for more details.
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</para>
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<para>
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You should have received a copy of the GNU General Public
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License along with this program; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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MA 02111-1307 USA
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</para>
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<para>
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For more details see the file COPYING in the source
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distribution of Linux.
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</para>
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</legalnotice>
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</bookinfo>
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<toc></toc>
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<chapter id="intro">
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<title>Introduction</title>
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<para>
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The Via VT82C686A "super southbridge" chips contain
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AC97-compatible audio logic which features dual 16-bit stereo
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PCM sound channels (full duplex), plus a third PCM channel intended for use
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in hardware-assisted FM synthesis.
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</para>
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<para>
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The current Linux kernel audio driver for this family of chips
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supports audio playback and recording, but hardware-assisted
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FM features, and hardware buffer direct-access (mmap)
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support are not yet available.
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</para>
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<para>
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This driver supports any Linux kernel version after 2.4.10.
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</para>
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<para>
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Please send bug reports to the mailing list <email>linux-via@gtf.org</email>.
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To subscribe, e-mail <email>majordomo@gtf.org</email> with
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</para>
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<programlisting>
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subscribe linux-via
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</programlisting>
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<para>
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in the body of the message.
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</para>
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</chapter>
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<chapter id="install">
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<title>Driver Installation</title>
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<para>
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To use this audio driver, select the
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CONFIG_SOUND_VIA82CXXX option in the section Sound during kernel configuration.
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Follow the usual kernel procedures for rebuilding the kernel,
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or building and installing driver modules.
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</para>
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<para>
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To make this driver the default audio driver, you can add the
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following to your /etc/conf.modules file:
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</para>
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<programlisting>
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alias sound via82cxxx_audio
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</programlisting>
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<para>
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Note that soundcore and ac97_codec support modules
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are also required for working audio, in addition to
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the via82cxxx_audio module itself.
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</para>
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</chapter>
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<chapter id="reportbug">
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<title>Submitting a bug report</title>
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<sect1 id="bugrepdesc"><title>Description of problem</title>
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<para>
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Describe the application you were using to play/record sound, and how
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to reproduce the problem.
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</para>
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</sect1>
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<sect1 id="bugrepdiag"><title>Diagnostic output</title>
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<para>
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Obtain the via-audio-diag diagnostics program from
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http://sf.net/projects/gkernel/ and provide a dump of the
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audio chip's registers while the problem is occurring. Sample command line:
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</para>
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<programlisting>
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./via-audio-diag -aps > diag-output.txt
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</programlisting>
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</sect1>
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<sect1 id="bugrepdebug"><title>Driver debug output</title>
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<para>
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Define <constant>VIA_DEBUG</constant> at the beginning of the driver, then capture and email
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the kernel log output. This can be viewed in the system kernel log (if
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enabled), or via the dmesg program. Sample command line:
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</para>
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<programlisting>
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dmesg > /tmp/dmesg-output.txt
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</programlisting>
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</sect1>
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<sect1 id="bugrepprintk"><title>Bigger kernel message buffer</title>
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<para>
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If you wish to increase the size of the buffer displayed by dmesg, then
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change the <constant>LOG_BUF_LEN</constant> macro at the top of linux/kernel/printk.c, recompile
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your kernel, and pass the <constant>LOG_BUF_LEN</constant> value to dmesg. Sample command line with
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<constant>LOG_BUF_LEN</constant> == 32768:
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</para>
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<programlisting>
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dmesg -s 32768 > /tmp/dmesg-output.txt
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</programlisting>
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</sect1>
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</chapter>
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<chapter id="bugs">
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<title>Known Bugs And Assumptions</title>
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<para>
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<variablelist>
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<varlistentry><term>Low volume</term>
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<listitem>
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<para>
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Volume too low on many systems. Workaround: use mixer program
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such as xmixer to increase volume.
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</para>
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</listitem></varlistentry>
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</variablelist>
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</para>
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</chapter>
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<chapter id="thanks">
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<title>Thanks</title>
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<para>
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Via for providing e-mail support, specs, and NDA'd source code.
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</para>
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<para>
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MandrakeSoft for providing hacking time.
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</para>
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<para>
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AC97 mixer interface fixes and debugging by Ron Cemer <email>roncemer@gte.net</email>.
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</para>
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<para>
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Rui Sousa <email>rui.sousa@conexant.com</email>, for bugfixing
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MMAP support, and several other notable fixes that resulted from
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his hard work and testing.
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</para>
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<para>
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Adrian Cox <email>adrian@humboldt.co.uk</email>, for bugfixing
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MMAP support, and several other notable fixes that resulted from
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his hard work and testing.
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</para>
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<para>
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Thomas Sailer for further bugfixes.
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</para>
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</chapter>
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<chapter id="notes">
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<title>Random Notes</title>
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<para>
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Two /proc pseudo-files provide diagnostic information. This is generally
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not useful to most users. Power users can disable CONFIG_SOUND_VIA82CXXX_PROCFS,
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and remove the /proc support code. Once
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version 2.0.0 is released, the /proc support code will be disabled by
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default. Available /proc pseudo-files:
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</para>
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<programlisting>
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/proc/driver/via/0/info
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/proc/driver/via/0/ac97
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</programlisting>
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<para>
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This driver by default supports all PCI audio devices which report
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a vendor id of 0x1106, and a device id of 0x3058. Subsystem vendor
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and device ids are not examined.
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</para>
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<para>
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GNU indent formatting options:
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<programlisting>
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-kr -i8 -ts8 -br -ce -bap -sob -l80 -pcs -cs -ss -bs -di1 -nbc -lp -psl
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</programlisting>
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</para>
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<para>
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Via has graciously donated e-mail support and source code to help further
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the development of this driver. Their assistance has been invaluable
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in the design and coding of the next major version of this driver.
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</para>
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<para>
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The Via audio chip apparently provides a second PCM scatter-gather
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DMA channel just for FM data, but does not have a full hardware MIDI
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processor. I haven't put much thought towards a solution here, but it
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might involve using SoftOSS midi wave table, or simply disabling MIDI
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support altogether and using the FM PCM channel as a second (input? output?)
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</para>
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</chapter>
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<chapter id="changelog">
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<title>Driver ChangeLog</title>
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<sect1 id="version191"><title>
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Version 1.9.1
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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DSP read/write bugfixes from Thomas Sailer.
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</para>
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</listitem>
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<listitem>
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<para>
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Add new PCI id for single-channel use of Via 8233.
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</para>
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</listitem>
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<listitem>
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<para>
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Other bug fixes, tweaks, new ioctls.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version1115"><title>
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Version 1.1.15
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Support for variable fragment size and variable fragment number (Rui
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Sousa)
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</para>
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</listitem>
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<listitem>
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<para>
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Fixes for the SPEED, STEREO, CHANNELS, FMT ioctls when in read &
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write mode (Rui Sousa)
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</para>
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</listitem>
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<listitem>
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<para>
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Mmaped sound is now fully functional. (Rui Sousa)
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</para>
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</listitem>
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<listitem>
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<para>
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Make sure to enable PCI device before reading any of its PCI
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config information. (fixes potential hotplug problems)
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</para>
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</listitem>
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<listitem>
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<para>
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Clean up code a bit and add more internal function documentation.
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</para>
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</listitem>
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<listitem>
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<para>
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AC97 codec access fixes (Adrian Cox)
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</para>
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</listitem>
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<listitem>
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<para>
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Big endian fixes (Adrian Cox)
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</para>
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</listitem>
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<listitem>
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<para>
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MIDI support (Adrian Cox)
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</para>
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</listitem>
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<listitem>
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<para>
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Detect and report locked-rate AC97 codecs. If your hardware only
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supports 48Khz (locked rate), then your recording/playback software
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must upsample or downsample accordingly. The hardware cannot do it.
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</para>
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</listitem>
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<listitem>
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<para>
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Use new pci_request_regions and pci_disable_device functions in
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kernel 2.4.6.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version1114"><title>
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Version 1.1.14
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Use VM_RESERVE when available, to eliminate unnecessary page faults.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version1112"><title>
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Version 1.1.12
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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mmap bug fixes from Linus.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version1111"><title>
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Version 1.1.11
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Many more bug fixes. mmap enabled by default, but may still be buggy.
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</para>
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</listitem>
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<listitem>
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<para>
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Uses new and spiffy method of mmap'ing the DMA buffer, based
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on a suggestion from Linus.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version1110"><title>
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Version 1.1.10
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Many bug fixes. mmap enabled by default, but may still be buggy.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version119"><title>
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Version 1.1.9
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Redesign and rewrite audio playback implementation. (faster and smaller, hopefully)
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</para>
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</listitem>
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<listitem>
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<para>
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Implement recording and full duplex (DSP_CAP_DUPLEX) support.
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</para>
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</listitem>
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<listitem>
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<para>
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Make procfs support optional.
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</para>
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</listitem>
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<listitem>
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<para>
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Quick interrupt status check, to lessen overhead in interrupt
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sharing situations.
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</para>
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</listitem>
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<listitem>
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<para>
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Add mmap(2) support. Disabled for now, it is still buggy and experimental.
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</para>
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</listitem>
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<listitem>
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<para>
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Surround all syscalls with a semaphore for cheap and easy SMP protection.
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</para>
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</listitem>
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<listitem>
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<para>
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Fix bug in channel shutdown (hardware channel reset) code.
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</para>
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</listitem>
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<listitem>
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<para>
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Remove unnecessary spinlocks (better performance).
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</para>
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</listitem>
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<listitem>
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<para>
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Eliminate "unknown AFMT" message by using a different method
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of selecting the best AFMT_xxx sound sample format for use.
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</para>
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</listitem>
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<listitem>
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<para>
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Support for realtime hardware pointer position reporting
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(DSP_CAP_REALTIME, SNDCTL_DSP_GETxPTR ioctls)
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</para>
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</listitem>
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<listitem>
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<para>
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Support for capture/playback triggering
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(DSP_CAP_TRIGGER, SNDCTL_DSP_SETTRIGGER ioctls)
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</para>
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</listitem>
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<listitem>
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<para>
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SNDCTL_DSP_SETDUPLEX and SNDCTL_DSP_POST ioctls now handled.
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</para>
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</listitem>
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<listitem>
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<para>
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Rewrite open(2) and close(2) logic to allow only one user at
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a time. All other open(2) attempts will sleep until they succeed.
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FIXME: open(O_RDONLY) and open(O_WRONLY) should be allowed to succeed.
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</para>
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</listitem>
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<listitem>
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<para>
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Reviewed code to ensure that SMP and multiple audio devices
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are fully supported.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version118"><title>
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Version 1.1.8
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Clean up interrupt handler output. Fixes the following kernel error message:
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</para>
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<programlisting>
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unhandled interrupt ...
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</programlisting>
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</listitem>
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<listitem>
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<para>
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Convert documentation to DocBook, so that PDF, HTML and PostScript (.ps) output is readily
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available.
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version117"><title>
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Version 1.1.7
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Fix module unload bug where mixer device left registered
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after driver exit
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version116"><title>
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Version 1.1.6
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Rewrite via_set_rate to mimic ALSA basic AC97 rate setting
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</para>
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</listitem>
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<listitem>
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<para>
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Remove much dead code
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</para>
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</listitem>
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<listitem>
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<para>
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Complete spin_lock_irqsave -> spin_lock_irq conversion in via_dsp_ioctl
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</para>
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</listitem>
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<listitem>
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<para>
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Fix build problem in via_dsp_ioctl
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</para>
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</listitem>
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<listitem>
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<para>
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Optimize included headers to eliminate headers found in linux/sound
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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|
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<sect1 id="version115"><title>
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Version 1.1.5
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</title>
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Disable some overly-verbose debugging code
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</para>
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</listitem>
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<listitem>
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<para>
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Remove unnecessary sound locks
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</para>
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</listitem>
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<listitem>
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<para>
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Fix some ioctls for better time resolution
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</para>
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</listitem>
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<listitem>
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<para>
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Begin spin_lock_irqsave -> spin_lock_irq conversion in via_dsp_ioctl
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</para>
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</listitem>
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</itemizedlist>
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</sect1>
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<sect1 id="version114"><title>
|
|
Version 1.1.4
|
|
</title>
|
|
<itemizedlist spacing="compact">
|
|
<listitem>
|
|
<para>
|
|
Completed rewrite of driver. Eliminated SoundBlaster compatibility
|
|
completely, and now uses the much-faster scatter-gather DMA engine.
|
|
</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</sect1>
|
|
|
|
</chapter>
|
|
|
|
<chapter id="intfunctions">
|
|
<title>Internal Functions</title>
|
|
!Isound/oss/via82cxxx_audio.c
|
|
</chapter>
|
|
|
|
</book>
|
|
|
|
|