patch-2.3.38 linux/Documentation/sound/via82cxxx.txt

• Lines: 147
• Date: Thu Jan 6 14:46:18 2000
• Orig file: v2.3.37/linux/Documentation/sound/via82cxxx.txt
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.37/linux/Documentation/sound/via82cxxx.txt linux/Documentation/sound/via82cxxx.txt
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+			Via motherboard audio driver
+	Copyright 1999,2000 Jeff Garzik <jgarzik@mandrakesoft.com>
+
+Driver software and documentation distributed under the GNU GENERAL
+PUBLIC LICENSE (GPL) Version 2. See the "COPYING" file distributed with
+this software for more info.
+
+
+
+Introduction
+------------------------------------------------------------------------
+The via82cxxx audio driver found in the drivers/sound directory
+of the kernel source tree is a PCI audio driver for audio chips
+found on Via-based motherboards, such as the MVP4.
+
+Currently the driver provides audio via SoundBlaster Pro compatibility,
+and MIDI via MPU-401 compatibility.  An AC97 mixing device is also
+supported, and is generally preferred over the SoundBlaster mixer.
+
+IMPORTANT NOTE:  Some users report that the SoundBlaster mixer does
+not work at all -- use the AC97 mixer if possible.
+
+Please send bug reports to the mailing list linux-via@gtf.org.
+To subscribe, e-mail majordomo@gtf.org with "subscribe linux-via" in the
+body of the message.
+
+
+Thanks
+------------------------------------------------------------------------
+Via for providing e-mail support, specs, and NDA's source code.
+
+MandrakeSoft for providing hacking time.
+
+AC97 mixer interface fixes and debugging by Ron Cemer <roncemer@gte.net>
+
+
+
+Installation
+------------------------------------------------------------------------
+If the driver is being statically compiled into the kernel, no
+configuration should be necessary.
+
+If the driver is being compiled as a module, generally two lines must
+be added to your /etc/conf.modules (or /etc/modules.conf) file:
+
+	alias sound via82cxxx
+	options sb support=1
+
+The second line is very important:  it tells the required 'sb' module
+not to load SoundBlaster support, but to instead let the Via driver
+do so at a later time.
+
+
+
+Driver notes
+------------------------------------------------------------------------
+This driver by default supports all PCI audio devices which report
+a vendor id of 0x1106, and a device id of 0x3058.  Subsystem vendor
+and device ids are not examined.
+
+Only supports a single sound chip, as this is a motherboard chipset.
+Some architecture remains for multiple cards, feel free to submit
+a patch to clean some of that up.  Ideally, 
+
+No consideration for SMP, this chipset is not known to be found on
+any SMP motherboards.  However, this will change when we start handling
+our own interrupts in "native mode."
+
+GNU indent formatting options:  -kr -i8 -pcs
+
+
+
+Tested Hardware
+------------------------------------------------------------------------
+The following is an _incomplete_ list of motherboards supported by this
+audio driver.  If your motherboard (or notebook) is not listed here,
+please e-mail the maintainer with details.
+
+	AOpen MX59 Pro (Apollo MVP4)
+
+
+
+The Future
+------------------------------------------------------------------------
+Via has graciously donated e-mail support and source code to help further
+the development of this driver.  Their assistance has been invaluable
+in the design and coding of the next major version of this driver.
+
+This audio chip supports a DirectSound(tm)-style hardware interface,
+with a single 16-bit stereo input channel, and a single 16-bit stereo
+output channel.  Data is transferred to/from the hardware using
+table-driven scatter-gather DMA buffers.
+
+Work is currently underway to support this "native mode" of the chip.
+When complete, SoundBlaster legacy mode will be completely removed.
+After a round of testing, this code will become version 2.0.0.
+
+Following the 2.0.0 release, the last major task to complete is
+MIDI support.  MPU-401 legacy support is available currently, but
+not well tested at all.
+
+The Via audio chip apparently provides a second PCM scatter-gather
+DMA channel just for FM data, but does not have a full hardware MIDI
+processor.  I haven't put much thought towards a solution here, but it
+might involve using SoftOSS midi wave table, or simply disabling MIDI
+support altogether and using the FM PCM channel as a second (input? output?)
+
+
+
+General To-do List (patches/suggestions welcome)
+------------------------------------------------------------------------
+Better docs
+
+Code review by sound guru(s)
+
+Native DSP audio driver using scatter-gather DMA, as described above
+
+Native MIDI driver, as described above
+
+
+
+Known bugs (patches/suggestions welcome)
+------------------------------------------------------------------------
+1) Two MIDI devices are loaded by the sound driver.  Eliminate one of them. 
+Sample /proc/sound output:
+
+	Midi devices:
+	0: Sound Blaster
+	1: VIA 82Cxxx Audio driver 1.1.2
+
+2) Two mixer devices are loaded by the sound driver.  Eliminate one of
+them.  At least one bug report says that SB mixer does not work at all,
+only AC97 mixer.  Sample /proc/sound output:
+
+	Mixers:
+	0: via82cxxxAC97Mixer
+	1: Sound Blaster
+
+3) After unloading the driver, a SoundBlaster MIDI device is still 
+listed in /proc/sound.  Investigate what is not being unloaded,
+and fix it.  Sample /proc/sound output, after 'rmmod via82cxxx':
+
+	Midi devices:
+	0: Sound Blaster
+
+