  Alsa-sound-mini-HOWTO
  Valentijn Sessink valentyn@alsa-project.org
  v0.2, 18 May 1999

  Describes the installation of the ALSA sound drivers for Linux. These
  sound drivers can be used as a replacement for the regular sound
  drivers, as they are fully compatible.
  ______________________________________________________________________

  Table of Contents
























































  1. Introduction

     1.1 Acknowledgments
     1.2 Revision History
     1.3 New versions of this document
     1.4 Feedback
     1.5 Distribution Policy

  2. Before you start

     2.1 Introduction
     2.2 General information about the ALSA drivers
     2.3 Supported hardware
     2.4 Other HOWTO's
        2.4.1 Sound cards
        2.4.2 Plug and Play cards
        2.4.3 Loadable modules
        2.4.4 Kerneld

  3. How to install ALSA sound drivers

     3.1 What you need
     3.2 Getting the drivers
     3.3 Extracting
     3.4 Compiling
     3.5 Preparing the devices

  4. Loading the driver

     4.1 Inserting with modprobe
     4.2 Which module for which card?
        4.2.1 Gravis UltraSound Extreme
        4.2.2 Gravis UltraSound MAX
        4.2.3 ESS AudioDrive
        4.2.4 Gravis UltraSound PnP
        4.2.5 UltraSound 32-Pro
        4.2.6 Soundblaster
        4.2.7 Soundblaster 16
        4.2.8 Yamaha OPL3-SA2/SA3 soundcards
        4.2.9 S3 SonicVibes
        4.2.10 Ensoniq/Soundblaster PCI64
        4.2.11 CS4232/4232A
        4.2.12 4235 and higher
     4.3 modprobe for drivers without auto-probing
        4.3.1 OPL3-SA2 and OPL3-SA3
        4.3.2 CS4232/CS4232A chips
        4.3.3 CS4235/CS4236/CS4236B/CS4237B/CS4238B/CS4239 chips
     4.4 The kerneld approach
     4.5 Backwards compatibility

  5. Testing and using

     5.1 The /proc filesystem
     5.2 The mixer
     5.3 The /dev/snd/ devices
     5.4 Additional information
        5.4.1 /proc/asound/#/pcm#0
        5.4.2 /proc/asound/#card#/sb16

  6. Tips and Troubleshooting

     6.1 Compiling the driver
        6.1.1 Linux kernel sourcetree
     6.2 Loading the driver
        6.2.1 Sound card compatibility
        6.2.2 ``Device busy'' or ``unresolved symbols''
        6.2.3 Unresolved symbols revisited
        6.2.4 Check the PnP setup
        6.2.5 Are your parameters right ?
     6.3 Driver loaded... but no sound
        6.3.1 Unmuting
        6.3.2 OSS/Linux compatibility
     6.4 General suggestions
        6.4.1 Try using ``insmod''
        6.4.2 Read the INSTALL file.
        6.4.3 Debug messages
        6.4.4 If all else fails...
     6.5 Bug reports
     6.6 Tip: playing CD's
     6.7 Tip: installing the MIDI serial driver
     6.8 Tip: new kernel? New modules!
     6.9 Tip: KDE and ALSA drivers
     6.10 Tip: use the ALSA devices
     6.11 Tip: removing all modules


  ______________________________________________________________________

  1.  Introduction

  This is the ALSA Sound drivers mini-HOWTO. It gives you information
  about installing and using the ALSA sound drivers for your soundcard.
  The ALSA drivers are fully modularized sound drivers that support
  kerneld and kmod. They are compatible with, but surpass the
  possibilities of, the current OSS API. In other words: compatible, but
  better.

  1.1.  Acknowledgments

  This documents contains information I got from the ALSA driver page.
  The structure was ripped off the SB-mini-HOWTO, mainly because it had
  about the structure I was looking for. Thanks to the SGML Tools
  package, this HOWTO is available in several formats, all generated
  from a common source file. Thanks to Erik Warmelink for proof reading,
  thanks to Alfred Munnikes for a couple of questions and helpful
  suggestions. Yamahata Isaku thanks for the Japanese translation,
  Miodrag Vallat for the translation in French. Later on, Steve Crowder
  did a great job by reading and editing the whole text.  Thanks to
  Marc-Aur`ele Darche, Piotr Ingling, Juergen Kahrs and Tim Pearce for
  useful tips and additions.

  1.2.  Revision History

  Version 1.4 - May 18, 1999. Included the URL to the French version,
  changed more URLs.

  Version 1.3 - May 16, 1999. Thanks to Jaroslav this HOWTO has found a
  home at the ALSA-project website.  As a result of that, some updates
  in mail and web addresses.

  Version 1.2 - May 11, 1999. Several updates.

  Version 1.1 - March 11, 1999. Added a couple of sound cards from the
  new 0.3 series drivers, wrote a bit about the 2.2 series kernel.

  Version 1.0 - February 8, 1999. Added a few things to the
  troubleshooting section, but we seem fairly complete.

  Version 0.3 beta - January 20, 1999. A link on the ALSA-homepage. Ha,
  we're official!


  Version 0.2 alpha - Mid January 1999, first .sgml-version.

  Version 0.1 alpha - January 1999, first version, mostly HTML.

  Still: please submit any patches in plain English, you native
  speakers!


  1.3.  New versions of this document

  The latest version can be found at http://www.alsa-
  project.org./~valentyn

  Other formats (full size html, sgml, txt) are in the directory other-
  formats.

  Yamahata Isaku has translated a Japanese version, which will be
  available at the Japanese ALSA site,
  http://plaza21.mbn.or.jp/~momokuri/alsa/index.html

  Miodrag Vallat translated a French version, which is available at
  http://www.freenix.fr/unix/linux/HOWTO/mini/Alsa.html.

  If you make a translation of this document into another language, let
  me know and I'll include a reference to it here.

  1.4.  Feedback

  I rely on you, the reader, to make this HOWTO useful. If you have any
  suggestions, corrections or comments, please send them to me (alsa-
  howto@alsa-project.org), and I will try to incorporate them in the
  next revision.

  Please note: I do not get a lot of mail about the ALSA drivers and any
  addition is welcome. Even a ``thank you for'' is appreciated - maybe
  it's not too much work to add a ``I appreciated most'' or ``this-or-
  that was not immediately clear to me''-section.

  If you publish this document on a CD-ROM or in hardcopy form, a
  complimentary copy would be appreciated. Mail me for my postal
  address. Also consider making a donation to the Linux Documentation
  Project to help support free documentation for Linux. Contact the
  Linux HOWTO co-ordinator, Tim Bynum linux-howto@metalab.unc.edu, for
  more information.

  1.5.  Distribution Policy

  Copyright 1998/1999 Valentijn Sessink

  This HOWTO is free documentation; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of the
  License, or (at your option) any later version.

  This document is distributed in the hope that it will be useful, but
  without any warranty; without even the implied warranty of
  merchantability or fitness for a particular purpose. See the GNU
  General Public License for more details.

  You can obtain a copy of the GNU General Public License by writing to
  the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
  USA.




  2.  Before you start



  2.1.  Introduction

  This document tries to help you install and use the ALSA sound drivers
  in your Linux system. The reference system is a Slackware 3.5
  distribution of Linux on an AMD/K6 computer (x86 compatible), but it
  should work with any other Linux distribution. I do not know if the
  ALSA drivers work on other platforms, according to the documentation,
  Alpha has been tested and proven to work.  I have only x86 PC's here,
  so any additional information you may have would be appreciated.

  It might be handy to read the Linux Sound HOWTO (see section Other
  HOWTO's), but that HOWTO focuses on the built-in kernel drivers.

  2.2.  General information about the ALSA drivers

  The ALSA sound driver was originally written as a replacement for the
  Linux kernel sound for Gravis UltraSound (GUS) cards. As this GUS
  replacement proved to be a success, the author started the ALSA
  project for a generic driver for several sound chips, with fully
  modularized design.

  It is compatible with the OSS/Free and OSS/Linux sound drivers (the
  drivers in the kernel), but has its own interface that is even better
  than the OSS drivers. A list of features can be found at
  http://www.alsa-project.org/intro.html

  The main page of the ALSA project is http://www.alsa-project.org/

  2.3.  Supported hardware

  The ALSA drivers support only a subset of all sound cards available.
  As the time of writing, the following cards are supported:

  ·  Cards with a Trident 4D Wave DX/NX chipset, thanks to Trident
     Microsystems who offered ALSA ``first cut'' GPL'd drivers (MIXER
     and PCM devices only) and documentation for their 4D Wave PCI audio
     chipsets.  See
     http://www.tridentmicro.com/HTML/products%20folder/audio.htm for
     more information. The drivers are now in cvs, and will be included
     with the ALSA 0.3.0-pre5 release.

  ·  Gravis Ultrasound (GUS): "PnP",  Extreme, Classic/ACE, MAX

  ·  Cards with a GUS chipset: Dynasonic 3-D, STB Sound Rage 32,
     UltraSound 32-Pro (STB)

  ·  Soundblaster: 1.0, 2.0, Pro, 16, AWE32/64, PCI64

  ·  ESS AudioDrive ESx688

  ·  ESS ES18xx (chipsets). Please note that I personally experienced a
     lot of trouble with the ESS1888. The developer of the driver for
     this card did his best, but to no avail.

  ·  ESS Solo-1 ES1938

  ·  Yamaha: OPL3-SA2, OPL3-SA3 (chipsets)

  ·  OAK Mozart

  ·  Schubert 32 PCI (PINE, S3 SonicVibes PCI chipset)

  ·  Ensoniq AudioPCI ES1370/1371 PCI soundcards (Soundblaster PCI64)

  ·  SonicVibes PCI soundcards (PINE Schubert 32 PCI)

     Then a whole lot of Crystal Semiconductors-based sound boards are
     supported.  These chips can be found in a lot of hardware, in
     separate cards (some Philips PCA series)and on motherboards (e.g.
     IBM Aptiva, Dell computers). Boards based on the following chipsets
     are supported:

  ·  4232

  ·  4232A

  ·  4235

  ·  4236B

  ·  4237B

  ·  4238B

  ·  4239

     A more recent list may be found inside the driver package itself,
     that is in doc/SOUNDCARDS

  2.4.  Other HOWTO's

  This ALSA-sound-mini-HOWTO is just mini. Other HOWTO's may help you
  out in case this one is too terse. I will name a few things you may
  come across while trying to install the ALSA drivers. HOWTO's can
  generally, be found at mirrors of Metalab (the former Sunsite). So
  take a look at http://metalab.unc.edu/LDP/mirrors.html and pick out
  your closest mirror site. You can find HOWTO's in the directory
  LDP/HOWTO/.  Please note: the links in this document will all be
  relative to /LDP/HOWTO/mini. If you look at this document from a
  reasonably good mirror site, you will find the HOWTO's.

  Then a note for the 2.2.x kernel series. For the 2.2.x kernel series,
  sound support is like any other support: it works, but it is different
  from what you used to do. This HOWTO (like any other HOWTO) will
  concentrate on the 2.0 series kernel, although I'll try to point out
  the differences.  I will gladly add anything that would help bring
  this HOWTO upto date with the 2.2 series kernel.

  2.4.1.  Sound cards

  Perhaps you bought a sound card already, or maybe it has been
  installed in your computer for ages. And now you are going to use it !
  Have a look at the Sound-HOWTO to see if this is all worth the
  trouble. (You might want to buy this new Mega-Rumble-Blaster first,
  then try the ALSA drivers.)

  2.4.2.  Plug and Play cards

  Most modern sound cards for the Intel platform are ISA PnP cards,
  which is an abbreviation for ''Plug and Play''. This means, that the
  card has to be configured by the operation system. This has to be done
  through an initialization routine at boot time. You probably need to
  configure your card with the PnP-utils-package. Every recent Linux
  distribution includes these tools. For usage have a look at the Plug-
  and-Play-HOWTO

  The ALSA-drivers seem to have built in their own ISA-PnP-support for a
  couple of sound cards. Unfortunately, as I cannot find documentation
  about this, I cannot tell you how it works. If anyone out there wants
  to try ALSA sound support while deliberately not using the ISA-PnP-
  tools, please drop me a line.

  2.4.3.  Loadable modules

  The ALSA sound drivers are built as modules. You can find more
  information about modules in the Kernel-HOWTO.  There is also a
  module-HOWTO, but that is unmaintained at the moment; take a look at
  the umaintained section of the Howto-HOWTO. There is a Modules-mini-
  HOWTO though that may be useful.

  2.4.4.  Kerneld

  Another HOWTO that will be useful for some, is the Kerneld-mini-HOWTO.
  Kerneld is a daemon that installs and removes kernel modules as
  needed. (I have zero experience with it, so additional information on
  the topic is welcome. The ALSA driver documentation contains some
  information about configuration of the kerneld, this has been included
  in this mini-HOWTO.)



  3.  How to install ALSA sound drivers



  3.1.  What you need



  ·  a functional Linux system (e.g. the Slackware distribution), with
     the "Development" packages installed (i.e. gcc, make etc.)

  ·  a supported sound card

  ·  some knowledge about Linux (meaning you know how to use "ls", "cd",
     "tar" etc.)

  ·  a root-account

     If you have a PnP card, you will also need:

  ·  the isapnptools software package.

     The INSTALL text in the driver directory suggests that for some
     cards, PnP support is native. I also received a suggestion from
     Jaroslav about this.  When I get further information about this
     topic I will add it to this mini-HOWTO.

  Please note that you should not have any sound drivers active when you
  want to use the ALSA drivers. If you have a kernel with sound drivers
  compiled in, you'll need a kernel recompilation. If you have the old
  "sound.o" module active, you need to deactivate it. If you use
  kerneld, this probably means deleting sound.o from the
  /lib/modules/<kernel_version>/misc directory.  Newer RedHat systems
  have a different sound approach, with several sound modules active.
  You need to deactivate them all.

  The 2.2 series kernel has a new approach to sound. You should include
  sound support here ! Yep, that's right: you add sound support to the
  kernel, but do not include any sound card. Then compile and install
  the kernel and after that, compile the ALSA-drivers.



  3.2.  Getting the drivers

  The ALSA drivers are available from ftp://ftp.alsa-project.org/pub/
  and there is a mirror at ftp://linux.a2000.nl/alsa For a fully
  functional ALSA-installation, you will need the driver, the libs and
  the utilities; e.g if you chose the mirror you would get
  ftp://linux.a2000.nl/alsa/driver/alsa-driver-0.3.0-pre4.tar.gz,
  ftp://linux.a2000.nl/alsa/lib/alsa-lib-0.3.0pre4.tar.gz and
  ftp://linux.a2000.nl/alsa/utils/alsa-utils-0.3.0-pre4.tar.gz (and NO
  these are not full links, you'd better look at the original place if
  there are newer versions available, simply get the last one).

  3.3.  Extracting

  You extract the drivers by some reasonable command, like the all-time
  tar -zxf <file>. For newbies and for those with amnesia:


       cd /usr/src






       tar -zxf ~/alsa-driver-0.3.0-pre4.tar.gz




  (If this worked you are either logged in as root always, which is the
  wrong way, stop here and read the DOS/Win95-to-Linux-HOWTO, or you
  already thought this would be the administrative thing you needed
  superuser/rootprivs for. So: for this you need rootprivs, type a "su"
  and the password).


       tar -zxf ~/alsa-lib-0.3.0pre4.tar.gz






       tar -zxf ~/alsa-utils-0.3.0-pre4.tar.gz




  Also working and more fun: find ~ -name alsa* -exec tar -zxf {} \;
  (Don't try this at home kids, it's just an example). Note that when
  downloading the drivers with Netscape, you may accidentally get
  unpacked drivers with a ".tgz" extension. If tar complains about the
  file format, you may get better results by leaving off the "z" in the
  tar options.

  3.4.  Compiling

  You need the drivers before you can compile and use the libs. You need
  the libs before you can compile or use the utils. So let's begin:


       cd alsa-driver-0.3.0-pre4



  (and for those not so experienced: try typing a <tab> (the "tab"-key)
  after "alsa-d". That's called command line completion.)


       ./configure






       make




  Now you need to be 'root' to install the stuff (you probably were
  "root" already)


       make install




  If this tells you that something like ``version.h'' cannot be found,
  then you probably do not have a proper kernel source tree. You need a
  couple of files of your kernel source to be able to compile the ALSA-
  drivers. Unpack your favorite linux-2.x.y.tar.gz in /usr/src, and
  issue a make menuconfig. (Actually, make symlinks may be enough).  Now
  compile the libraries:


       cd ../alsa-lib-0.3.0-pre4






       ./configure






       make






       make install




  OK, you're getting it, the utilities:


       cd ../alsa-utils-0.3.0-pre4



       ./configure






       make






       make install




  Note: you can leave out the "make install" for the utilities at first.
  You could even leave out the whole library-making and utility-making,
  just to check if the driver works.

  3.5.  Preparing the devices

  There is a script in the driver-directory that will install the ALSA-
  sound-devices in your /dev directory. Type


       ./snddevices




  from the driver-directory. There should be a /dev/snd subdirectory now
  (test if it is there. If you are not familiar with even the "ls" com­
  mand, please consider reading other HOWTO's first. You should have
  some basic Linux knowledge to install these drivers).

  Now you're ready to insert the driver, so please turn over to the next
  paragraph.

  4.  Loading the driver

  There are two ways to use the ALSA-sound-modules. I personally prefer
  using the manual method, meaning that I insert the driver at startup.
  The ALSA-drivers were designed as loadable/unloadable modules - for
  instance they do not reset the mixer after loading - so you can easily
  use the kerneld approach.

  Please do read the section ``Backwards Compatibility''.  You need it
  to have sound support ``the old way''.

  4.1.  Inserting with modprobe

  Note: If you have a PnP audio-card, you first need to set it to the
  right (or at least some known) IO/IRQ/DMA. See the Plug-and-Play-
  HOWTO. Did you configure your Plug-and-Play-soundcard ? Ok, then read
  on please.  The main part is: do a "modprobe snd-<soundcard>". This
  should do the trick. Please note that not all distributions do include
  /sbin in your path.  If you get a "bash: modprobe: command not found",
  this will most likely mean that modprobe is not in your path. Try
  "/sbin/modprobe snd-sb16", or try to find the modprobe utility
  elsewhere.


  The most important difficulty is with the Crystal chipsets, for these
  the ALSA-drivers are not auto probing. More recent information may be
  acquired from the INSTALL file in the driver-directory. Two examples,
  then a list: Gravis UltraSound (GUS) and compatibles:


       /sbin/modprobe snd-gusclassic




  For all 16-bit Soundblaster-cards (SoundBlaster 16 (PnP), SoundBlaster
  AWE 32 (PnP), SoundBlaster AWE 64 (PnP):


       /sbin/modprobe snd-sb16





  4.2.  Which module for which card?


  4.2.1.  Gravis UltraSound Extreme


  modprobe snd-gusextreme

  4.2.2.  Gravis UltraSound MAX


  modprobe snd-gusmax




  4.2.3.  ESS AudioDrive

  ESS AudioDrive ES-1688 and ES-688 soundcards

  modprobe snd-audiodrive1688


  4.2.4.  Gravis UltraSound PnP

  Gravis UltraSound PnP, Dynasonic 3-D/Pro, STB Sound Rage 32 and other
  soundcards based on AMD InterWave (tm) chip.

  modprobe snd-interwave

  4.2.5.  UltraSound 32-Pro

  UltraSound 32-Pro (soundcard from STB used by Compaq) and other
  soundcards based on AMD InterWave (tm) chip with TEA6330T circuit for
  extended control of bass, treble and master volume

  modprobe snd-interwave-stb

  4.2.6.  Soundblaster

  8-bit Soundblaster cards (SoundBlaster 1.0, SoundBlaster 2.0,
  SoundBlaster Pro)

  modprobe snd-sb8

  4.2.7.  Soundblaster 16

  16-bit SoundBlaster cards (SoundBlaster 16 (PnP), SoundBlaster AWE 32
  (PnP), SoundBlaster AWE 64 (PnP). Please note: this module does not
  support the SoundBlaster VibraX16 soundcard.

  modprobe snd-sb16

  4.2.8.  Yamaha OPL3-SA2/SA3 soundcards

  Just "modprobe snd-opl3sa" will not work, this driver does not do
  autoprobing.  See below.

  4.2.9.  S3 SonicVibes

  S3 SonicVibes PCI soundcards. (PINE Schubert 32 PCI)

  modprobe snd-sonicvibes


  4.2.10.  Ensoniq/Soundblaster PCI64

  Ensoniq AudioPCI ES1370/1371 PCI soundcards. (SoundBlaster PCI 64)

  modprobe snd-audiopci


  4.2.11.  CS4232/4232A

  All soundcards based on CS4232/CS4232A chips.  Just "modprobe snd-
  card-cs4232" will not work, no auto-probing. See below.


  4.2.12.  4235 and higher

  All soundcards based on CS4235/CS4236/CS4236B/CS4237B/CS4238B/CS4239
  chips.  Just "modprobe snd-card-cs4236" will not work, no auto-
  probing. See below.


  4.3.  modprobe for drivers without auto-probing

  If you have a non-autoprobing driver, you need to supply additional
  info at startup to have the driver work. More information can be found
  in the file INSTALL in the driver directory.

  4.3.1.  OPL3-SA2 and OPL3-SA3

  According to the INSTALL file you need to supply all the information
  for this driver. If you initialized the card with the isapnp-tools,
  you can probably get info from the /etc/isapnp.conf file for the
  following values:


       snd_port - control port # for OPL3-SA chip
       snd_wss_port - WSS port # for OPL3-SA chip (0x530,0xe80,0xf40,0x604)
       snd_midi_port - port # for MPU-401 UART (0x300,0x330), -1 = disable
       snd_fm_port - FM port # for OPL3-SA chip (0x388), -1 = disable
       snd_irq - IRQ # for OPL3-SA chip (5,7,9,10)
       snd_dma1 - first DMA # for Yamaha OPL3-SA chip (0,1,3)
       snd_dma1_size - max first DMA size in kB (4-64kB)
       snd_dma2 - second DMA # for Yamaha OPL3-SA chip (0,1,3), -1 = disable
       snd_dma2_size - max second DMA size in kB (4-64kB)



  You would do a "modprobe snd-opl3sa snd_port=0xNNN snd_wss_port=0x530
  snd_midi_port=-1 snd_fm_port=0x388 snd_irq=5 snd_dma1=0
  snd_dma1_size=NN snd_dma2=1 snd_dma2_size=NN" to load this driver
  (without midi-support. I am still convinced that midi-support is the
  thing you need when you have synthesizers and stuff and want to con­
  nect them to your Linux box. Never needed Midi-support even to play
  midi-files.)

  Note that the "NN" values need to be supplied, only I do not know what
  would be reasonable values. I do not know if the dma size option is
  really required.

  4.3.2.  CS4232/CS4232A chips

  According to the INSTALL file you need to supply the main port for
  this card. Note that with the driver for 3235/6/7/8/9 cards, the one
  below, I ended up supplying all information (except DMA-size),
  otherwise the driver did not work.  So you may as well use the whole
  command line to insert the driver. If you initialized the card with
  the isapnp-tools, you can probably get info from the /etc/isapnp.conf
  file for the following values:


       snd_port - port # for CS4232 chip (PnP setup - 0x534)
       snd_cport - control port # for CS4232 chip (PnP setup - 0x120)
       snd_mpu_port - port # for MPU-401 UART (PnP setup - 0x300), -1 = disable
       snd_fm_port - FM port # for CS4232 chip (PnP setup - 0x388), -1 = disable
       snd_jport - joystick port for CS4232 chip (PnP setup - 0x200), -1 =
       disable
       snd_irq - IRQ # for CS4232 chip (5,7,9,11,12,15)
       snd_mpu_irq - IRQ # for MPU-401 UART (9,11,12,15)
       snd_dma1 - first DMA # for CS4232 chip (0,1,3)
       snd_dma1_size - max first DMA size in kB (4-64kB)
       snd_dma2 - second DMA # for Yamaha CS4232 chip (0,1,3), -1 = disable
       snd_dma2_size - max second DMA size in kB (4-64kB)




  You would do a "modprobe snd-card-cs4232 snd_port=0x534
  snd_cport=0x120 snd_mpu_port=-1 snd_fm_port=0x388 snd_jport=-1
  snd_irq=5 snd_dma1=0 snd_dma1_size=NN snd_dma2=1 snd_dma2_size=NN" to
  load the driver for a "standard configured" soundcard. (Without midi-
  support, see the note at Yamaha OPL-3, and no joystick support). If
  you used different values in /etc/isapnp.conf, then you would use the
  values here also (Note: it can be wise to use your brains anyway ;)

  Note that the "NN" values need to be supplied, only I do not know what
  would be reasonable values. I do not know if the dma size option is
  really required.

  4.3.3.  CS4235/CS4236/CS4236B/CS4237B/CS4238B/CS4239 chips

  According to the INSTALL file you need to supply the main port and
  control ports for this card. Note that with a CS4237B card, I ended up
  supplying all information (except DMA-size), otherwise the driver did
  not work. So you may as well use the whole command line to insert the
  driver, and not only supply snd_port and snd_cport. If you initialized
  the card with the isapnp-tools, you can probably get info from the
  /etc/isapnp.conf file for the following values:






  snd_port - port # for CS4232 chip (PnP setup - 0x534)
  snd_cport - control port # for CS4232 chip (PnP setup - 0x120)
  snd_mpu_port - port # for MPU-401 UART (PnP setup - 0x300), -1 = disable
  snd_fm_port - FM port # for CS4232 chip (PnP setup - 0x388), -1 = disable
  snd_jport - joystick port for CS4232 chip (PnP setup - 0x200), -1 = disable
  snd_irq - IRQ # for CS4232 chip (5,7,9,11,12,15)
  snd_mpu_irq - IRQ # for MPU-401 UART (9,11,12,15)
  snd_dma1 - first DMA # for CS4232 chip (0,1,3)
  snd_dma1_size - max first DMA size in kB (4-64kB)
  snd_dma2 - second DMA # for Yamaha CS4232 chip (0,1,3), -1 = disable
  snd_dma2_size - max second DMA size in kB (4-64kB)




  You would do a "modprobe snd-card-cs4232 snd_port=0x534
  snd_cport=0x120 snd_mpu_port=-1 snd_fm_port=0x388 snd_jport=-1
  snd_irq=5 snd_dma1=0 snd_dma1_size=NN snd_dma2=1 snd_dma2_size=NN" to
  load the driver. (Without midi-support, see the note at Yamaha OPL-3,
  and no joystick support).  Notes:

  ·  the "NN" values need to be supplied, only I do not know what would
     be reasonable values.

  ·  my CS4237B works fine without explicit dma size option.

  4.4.  The kerneld approach

  kerneld is a daemon that inserts modules on request, and unloads them
  once they are not in use anymore. Since I have no experience with
  kerneld, I do not know if the information below is accurate. The info
  comes from the INSTALL file in the ALSA-drivers package. Excellent
  information about kerneld can be found in the kerneld-mini-HOWTO.

  Follow these steps:

  ·  Edit your /etc/conf.modules (see below for examples)

  ·  Run 'modprobe snd-card' where card is name of your card [Which I
     find rather strange, since kerneld is supposed to load them? VS]

     Example for /etc/conf.modules for Gravis UltraSound PnP soundcard:


       alias char-major-14 snd
       alias snd-minor-oss-0 snd-interwave
       alias snd-minor-oss-3 snd-pcm1-oss
       alias snd-minor-oss-4 snd-pcm1-oss
       alias snd-minor-oss-5 snd-pcm1-oss
       alias snd-minor-oss-12 snd-pcm1-oss
       alias snd-card-0 snd-interwave
       options snd snd_major=14 snd_cards_limit=1
       options snd-interwave snd_index=1 snd_id="guspnp" snd_port=0x220 snd_irq=5
       snd_dma1=5 snd_dma2=6




  Example if you want use more soundcards in one machine (configuration
  below is for Sound Blaster 16 and Gravis UltraSound Classic):






  alias char-major-14 snd
  alias snd-minor-oss-0 snd-mixer
  alias snd-minor-oss-3 snd-pcm1-oss
  alias snd-minor-oss-4 snd-pcm1-oss
  alias snd-minor-oss-5 snd-pcm1-oss
  alias snd-minor-oss-12 snd-pcm1-oss
  alias snd-card-0 snd-sb16
  alias snd-card-1 snd-gusclassic
  options snd snd_major=14 snd_cards_limit=2
  options snd-sb16 snd_index=1 snd_port=0x220 snd_irq=5 snd_dma8=1 snd_dma16=5
  options snd-gusclassic snd_index=2 snd_irq=11 snd_dma1=6 snd_dma2=7




  Example if two Gravis UltraSound Classic soundcards are present in
  system:


       alias char-major-14 snd
       alias snd-minor-oss-0 snd-mixer
       alias snd-minor-oss-3 snd-pcm1-oss
       alias snd-minor-oss-4 snd-pcm1-oss
       alias snd-minor-oss-5 snd-pcm1-oss
       alias snd-minor-oss-12 snd-pcm1-oss
       alias snd-card-0 snd-gusclassic
       alias snd-card-1 snd-gusclassic
       options snd snd_major=14 snd_cards_limit=2
       options snd-gusclassic snd_index=1,2 snd_port=0x220,0x260 snd_irq=5,11
       snd_dma1=5,6 snd_dma2=7,3





  4.5.  Backwards compatibility

  If you want to preserve OSS/Free or OSS/Linux compatibility, you need
  to insert one more driver: the snd-pcm1-oss driver for OSS-
  compatibility.  Issue a


       modprobe snd-pcm1-oss




  This will give you /dev/audio and /dev/dsp-support, just as the
  OSS/Free (kernel) drivers and OSS/Linux (the $25 ones) do. Note that
  this is only an emulation.


  5.  Testing and using

  Now you should test if the sound driver really is available, then try
  to use it.

  5.1.  The /proc filesystem

  You can find a lot of useful information about your system in the
  /proc subdirectory. /proc is a "virtual" filesystem, meaning that it
  does not exist in real life, but merely is a mapping to various
  processes and tasks in your computer. In order for /proc to work, you
  need to have support for it compiled into your kernel. Most linux
  distributions have this as a default, but if you compiled a kernel and
  left /proc out obviously there won't be anything in /proc.
  /proc/modules gives information about loaded modules. Once the ALSA
  sound drivers are loaded, if you type cat /proc/modules you should see
  something like:


       snd-pcm1-oss      4            0
       snd-sb16          1            1
       snd-sb-dsp        4    [snd-sb16]      0
       snd-pcm1          4    [snd-pcm1-oss snd-sb-dsp]      0
       snd-pcm           3    [snd-pcm1-oss snd-sb16 snd-sb-dsp snd-pcm1]    0
       snd-mixer         3    [snd-pcm1-oss snd-sb16 snd-sb-dsp]      1
       snd-mpu401-uart   1    [snd-sb16]      0
       snd-midi          4    [snd-sb16 snd-sb-dsp snd-mpu401-uart]   0
       snd-opl3          1    [snd-sb16]      0
       snd-synth         1    [snd-sb16 snd-opl3]     0
       snd-timer         1    [snd-opl3]      0
       snd               8    [snd-pcm1-oss snd-sb16 snd-sb-dsp snd-pcm1 snd-pcm snd-mixer snd-mpu401-uart snd-midi snd-opl3 snd-synth snd-timer]    0




  If something went wrong during the installation of the driver, you
  will still see a couple of "snd" devices, but there won't be sound
  support.

  For example (Note: you should never issue this command as follows, the
  cs4236 driver needs options):


       win3:~# modprobe snd-card-cs4236
       /lib/modules/2.0.35/misc/snd-card-cs4236.o: init_module: Device or resource busy
       snd-mixer: Device or resource busy
       win3:~# cat /proc/modules
       snd-cs4236        2           0
       snd-cs4231        3    [snd-cs4236]    0
       snd-timer         1    [snd-cs4231]    0
       snd-pcm1          4    [snd-cs4236 snd-cs4231] 0
       snd-mixer         3    [snd-cs4236 snd-cs4231] 0
       snd-pcm           3    [snd-cs4236 snd-cs4231 snd-pcm1]       0
       snd-mpu401-uart   1           0
       snd-midi          4    [snd-mpu401-uart]       0
       snd-opl3          1           0
       snd-synth         1    [snd-opl3]      0
       snd-timer         1    [snd-cs4231 snd-opl3]   0
       snd               8    [snd-cs4231 snd-timer snd-pcm1 snd-mixer snd-pcm]     0




  You can check the existence of a soundcard by looking in
  /proc/asound/cards.  For example:


       bash$ cat /proc/asound/cards
       0 [card1          : SB16 - Sound Blaster 16
                           Sound Blaster 16 at 0x220, irq 5, dma 1&5




  In the previous example (where I forgot the options) the output would
  have been:




  win3:~# cat /proc/asound/cards
  --- no soundcards ---




  A working CS4236 card would produce


       0 [card1         ]: CS4236 - CS4237B
                           CS4237B at 0x534, irq 7, dma 1&0




  If you checked and doublechecked your settings and still see no sound
  card, take a look at the troubleshooting section.

  The /proc/asound/ virtual directory shows lots of other information
  about the driver. Please note that /proc/asound/ will only exist after
  you inserted the first ALSA module. If there is no /proc/asound, it
  simply means that the "snd" module was not loaded properly. You can
  find installed cards in /proc/asound/cards, then find information
  about card0 in /proc/asound/0, /proc/asound/1 for card1 etcetera.

  If cat /proc/asound/ shows something like


             ES1370 DAC2/ADC
             Playback isn't active.
             Record isn't active.



  this means that your driver is ready to go, but is not doing anything
  right now. (So everything went well).

  There is a third method to find information about the sound devices,
  namely if you inserted the OSS compatible driver there is a
  /dev/sndstat device. The ALSA drivers kindly request that you not to
  rely on this information as it is only there for compatibility with
  the OSS drivers and better information can easily be obtained from
  /proc/asound/.

  5.2.  The mixer

  Once the drivers for your sound card have been installed and your
  /proc filesystem tells you so, you can try to make a real sound. First
  of all, install the utility package, or at least put the "amixer"
  command in some reasonable place (like /usr/local/bin). First look at
  the mixer settings by typing "amixer". The output from amixer can
  greatly differ from card to card. My Soundblaster 16 shows:


       Master         0  % (-14.00dB) : 0  % (-14.00dB)
       Bass           0  % (-14.00dB) : 0  % (-14.00dB)
       Treble         0  % (-14.00dB) : 0  % (-14.00dB)
       Synth          0  % (-62.00dB) : 0  % (-62.00dB)
       PCM            0  % (-62.00dB) : 0  % (-62.00dB)
       Line-In        0  % (-62.00dB) : 0  % (-62.00dB) Mute
       MIC            0  % (-62.00dB) : 0  % (-62.00dB) Mute
       CD             0  % (-62.00dB) : 0  % (-62.00dB) Mute
       In-Gain        0  % (-18.00dB) : 0  % (-18.00dB)
       Out-Gain       0  % (-18.00dB) : 0  % (-18.00dB)
       PC Speaker     0  % (-18.00dB) : 0  % (-18.00dB)

  My Crystal 4237B based soundcard has a lot of other options:


       Master D       0  % (-22.00dB) : 0  % (-22.00dB) Mute
       3D Center      0  % (-22.50dB) : 0  % (-22.50dB)
       3D Space       0  % (-22.50dB) : 0  % (-22.50dB) Mute
       Synth          0  % (-94.50dB) : 0  % (-94.50dB) Mute
       FM             0  % (-94.50dB) : 0  % (-94.50dB) Mute
       DSP            0  % (-94.50dB) : 0  % (-94.50dB) Mute
       PCM            0  % (-94.50dB) : 0  % (-94.50dB) Mute
       Line-In        0  % (-34.50dB) : 0  % (-34.50dB) Mute
       MIC            0  % (-22.50dB) : 0  % (-22.50dB) Mute
       CD             0  % (-34.50dB) : 0  % (-34.50dB) Mute
       Record-Gain    0  % (  0.00dB) : 0  % (  0.00dB)
       In-Gain        0  % (-18.00dB) : 0  % (-18.00dB)
       Loopback       0  % (-94.50dB) : 0  % (-94.50dB) Mute
       Mono           0  % (-45.00dB) : 0  % (-45.00dB) Mute
       Aux A          0  % (-34.50dB) : 0  % (-34.50dB) Mute




  You have noticed the "Mute" entry, the CS4237B even mutes the master
  channel.  For the CS4237B, I would have to type amixer "master d"
  unmute to even be able to produce any sound at all. The Soundblaster
  does not have muted output, but amixer master 100 unmute would set the
  volume to 100% and unmute the master. You can use a number, a word
  like "mute" or "unmute", or both. Type amixer "master d" 100; amixer
  pcm 100 unmute to set the CS4237B card to maximum master volume and
  unmute PCM volume and set it to maximum. For separate L/R settings you
  use a colon, for example amixer CD 25:50. (No, I don't know which one
  is the left or right channel, but let me emphasize that this also
  depends heavily on the position of your speakers)

  You would set the CD channel to record by typing amixer cd rec and
  stop the recording setting again by typing amixer cd norec.  If you
  would like to record something from the microphone, you would probably
  use amixer record-gain 100; amixer mic 100 rec mute. (Using the
  microphone input unmuted will produce loud high-pitched sound if your
  mic picks up its own signal from the speakers again).  Unfortunately I
  have not been able to change the volume of the "3d center" and "3d
  space" settings with amixer. If anyone succeeds please let me know.
  You can use alsamixer for this job.

  The ALSA FAQ says that it is possible to restore mixer settings with
  cat <file> > /proc/asound/#/mixerC0D0, where <file> was obtained from
  /proc/asound/#/mixerC0D0. I have not been able to reproduce this as my
  system complains about non-existing devices.

  5.3.  The /dev/snd/ devices

  The alsa drivers have native sound-devices in the /dev/snd/ directory.
  If you have  one card you might see the following devices:


       /dev/snd/pcmC0D0 - the raw audio device for the card
       /dev/snd/mixerC0D0 - the mixer for card 0
       /dev/snd/controlC0D0 - the control device for card 0




  The first number means the number of the soundcard, the second number
  (if any) is the number of the device. A sound card with two PCM
  devices would have a pcmC0D0 and pcmC0D1 device.  Please note: the
  ALSA devices have changed between the previous version. Older ALSA
  drivers use /dev/snd/pcm00 (first number is the card, second number is
  the device).  If this HOWTO uses the older notation, please drop me a
  line so I can correct it.

  Now you are ready to put any soundfile you want into the PCM device of
  the first card. So try to cat any textfile (any file) to
  /dev/snd/pcmC0D0, like this: cat <filename> > /dev/snd/pcmC0D0. The
  filename can be any file, as long as it has some length. If you have a
  soundfile lying around somewhere, you could try that. You could also
  get the file at http://www.ldp.org/sounds/english.au this is Linus
  Torvalds saying how to pronounce Linux.

  The default setting of your sound device is 8000 Hz, 8 bit. That means
  that the "english.au" file mentioned above will produce speech, other
  test files will probably just produce noise. If you do not hear
  anything, check your speakers, try to run "amixer" again or consult a
  doctor.  (Later on you can easily use the full 48 KHz, 16 bit features
  of your sound card, by using your favourite sound player like sox or
  mpg123).

  If you loaded the "snd-pcm1-oss" module, you can also use the OSS-
  compatibility to access your sound card. The following mappings are
  made:


       /dev/snd/pcmC0D0 -> /dev/audio0 (/dev/audio) -> minor 4
       /dev/snd/pcmC0D0 -> /dev/dsp0 (/dev/dsp) -> minor 3
       /dev/snd/pcmC0D1 -> /dev/adsp0 (/dev/adsp) -> minor 12
       /dev/snd/pcmC1D0 -> /dev/audio1 -> minor 4+16 = 20
       /dev/snd/pcmC1D0 -> /dev/dsp1 -> minor 3+16 = 19
       /dev/snd/pcmC1D1 -> /dev/adsp1 -> minor 12+16 = 28
       /dev/snd/pcmC2D0 -> /dev/audio2 -> minor 4+32 = 36
       /dev/snd/pcmC2D0 -> /dev/dsp2 -> minor 3+32 = 39
       /dev/snd/pcmC2D1 -> /dev/adsp2 -> minor 12+32 = 44





  5.4.  Additional information

  The INSTALL file in the ALSA driver directory mentions some tricks to
  tell the driver which settings to use. If you need these commands it
  will depend on the application you use to play sound. Regular sound
  playing applications, like mpg123, sox (mostly called with the
  ``play'' command), or X11 applications like RealPlayer will probably
  do fine without these. I never used these anyway.

  5.4.1.  /proc/asound/#/pcm#0




       "Playback erase" - erase all additional informations about OSS applications
       "Playback <app_name> <fragments> <fragment_size> [<options>]"
       "Record erase" - erase all additional informations about OSS applications
       "Record <app_name> <fragments> <fragment_size> [<options>]"




  <app_name> - name of application with (highter priority) or without
  path

  <fragments> - number of fragments or zero if auto

  <fragment_size> - size of fragment in bytes or zero if auto

  <options> - optional parameters

  WR_ONLY - if application tries open pcm device with O_RDWR driver
  rewrites this to O_WRONLY (playback) - good for Quake etc...

  Examples:


       echo "Playback x11amp 128 16384" > /proc/asound/0/pcm0o
       echo "Playback squake 0 0 WR_ONLY" > /proc/asound/0/pcm0o




  5.4.2.  /proc/asound/#card#/sb16




       "Playback 8" -> driver will use always 8-bit DMA channel for playback.
       "Playback 16" -> driver will use always 16-bit DMA channel for playback.
       "Playback auto" (default) -> driver will use auto mode (first opened direction will use 16-bit DMA channel).
       "Record 8" -> driver will use always 8-bit DMA channel for record.
       "Record 16" -> driver will use always 16-bit DMA channel for record.
       "Record auto" (default) -> driver will use auto mode (first opened direction will use 16-bit DMA channel).




  Example: echo "Record 16" > /proc/asound/0/sb16

  For further reference, please consult the INSTALL file.

  6.  Tips and Troubleshooting

  Please take a look at the FAQ file in the sound driver directory. This
  section is still under construction.

  6.1.  Compiling the driver


  6.1.1.  Linux kernel sourcetree

  If your ALSA drivers do not compile correctly and tell you things
  about ``version.h'' or other header-files that cannot be found, this
  can mean that you do not have the kernel header files.  Take a look at
  the kernel-HOWTO, unpack a recent kernel in /usr/src and issue a make
  config.


  6.2.  Loading the driver

  Please check the following items.


  6.2.1.  Sound card compatibility

  Are you 100% sure that your sound card IS supported ? Do check it
  again.  Sometimes an X123 is not exactly an X123b and you might be
  wasting time.  On the other hand, even a supported card can give you
  troubles - it took me two hours to figure out the installation of a
  CS4237B which was, after all, just a fine example of RTFM.


  6.2.2.  ``Device busy'' or ``unresolved symbols''

  You might have a 2.0.x kernel with sound support compiled in, or the
  OSS/Lite (kernel) sound driver could be loaded (check with cat
  /proc/modules). Remove the driver or recompile the kernel (have a look
  at the Kernel-HOWTO).

  The sound module in the 2.0 series kernel is called ``sound.o'' and
  should not be active.  (The ALSA driver ``snd.o'' is OK, though).

  If you have a 2.2.x series kernel without sound driver compiled in,
  the ALSA drivers will not work, too.

  I know it this is confusing, so let me try to explain it one more
  time. If you have a 2.0.x series kernel (the command ``uname -a''
  tells you something like ``Linux penguin 2.0.35 #6 Wed Sep 23 10:19:16
  CEST 1998 i686 unknown'') then you need to leave out sound drivers in
  the kernel.

  If you have a 2.2.x series kernel you do need the sound drivers. A 2.2
  series kernel should be compiled with sound support, but without any
  sound card driver. So you select sound support but make sure that no
  specific sound card driver will be compiled.


  6.2.3.  Unresolved symbols revisited

  Another source of ``unresolved symbols'' messages could be a new
  kernel with older drivers. Please recompile the ALSA drivers after you
  recompile a new kernel. This will make sure that the drivers match
  your new kernel.


  6.2.4.  Check the PnP setup

  Are you sure that your card is active? Take another look at the PnP-
  HOWTO and check if you activated your sound card correctly.


  6.2.5.  Are your parameters right ?

  Check, doublecheck your sound card parameters. Please note: 534 is not
  543, nor is 0x534 the same as 534.

  Also, some sound cards must be loaded by a different name than might
  be expected. Take a break, a beer or whatever, and look again at your
  ``modprobe'' command. For example the Crystal 4232 driver should be
  inserted by modprobe snd-card-cs4232, not ``snd-cs4231'', and the
  SoundBlaster PCI 64 should be loaded with ``snd-audiopci'', not snd-
  es1370. (It's all in the docs, and even though I wrote the HOWTO, I
  once spent an evening trying to persuade snd-cs4231 to make sound).


  6.3.  Driver loaded... but no sound



  6.3.1.  Unmuting

  The ALSA drivers can use the ``muting'' facilities that most
  soundcards have. If you loaded the sound drivers and everything is
  fine but you get nothing but silence, then you probably forgot to
  unmute your card. You need ``amixer'' or ``alsamixer'' for this, both
  from the ALSA-util package.  Just typing


  amixer -c 1 master 70:70 unmute
  amixer -c 1 pcm 70:70 unmute
  amixer -c 1 cd 70:70 unmute




  should do for most applications.


  6.3.2.  OSS/Linux compatibility

  If this is the first time you use the ALSA drivers and you used the
  built-in sound drivers before, you probably want to have backwards
  compatible sound (i.e. use the /dev/pcmX devices). You need to load
  the ``OSS compatibility driver'' for this. Do a modprobe snd-pcm1-oss.
  (See the end of the section about loading the driver). Please note:
  snd-pcm1-oss is not equal to snd-pcm1, you need snd-pcm1-oss for old-
  fashioned sound support.


  6.4.  General suggestions



  6.4.1.  Try using ``insmod''

  It can always be useful to start with "insmod" instead of kerneld.
  Maybe you actually see the error on screen.


  6.4.2.  Read the INSTALL file.

  A lot of information can be found in the INSTALL file in the drivers
  directory. If your driver won't work check if there is additional
  information available.


  6.4.3.  Debug messages

  As a last resort, you can rebuild the driver and tell it to send debug
  information to /var/log/messages. Go to the driver-directory with cd
  /usr/src/alsa-driver-....  and type:



       ./configure --with-debug=detect; make clean; make




  Remove the driver (as far as it is active, see below for a general
  remove statement).  Then use the "modprobe" statement you used before
  to insert the newly compiled driver.  Look in /var/log/messages if
  there are any messages.


  6.4.4.  If all else fails...

  If these messages doesn't help you, send a message to the ALSA users
  mailing list, alsa-user@alsa-project.org.

  Include the following information:

  ·  soundcard name + chip names present on your soundcard

  ·  relevant sections in your isapnp.conf if you have ISA PnP soundcard

  ·  your conf.modules or line which you activate ALSA driver

  ·  all messages from /var/log/messages which should be relevant to the
     ALSA driver


  6.5.  Bug reports

  If you found a bug, the ALSA developers would like to know the
  following things (at minimum)

  1. driver + kernel version: 'cat /proc/asound/version'

  2. soundcard info

  ·  soundcard name provided by manufacture

  ·  list of chips which soundcard have onboard

  ·  contents of 'cat /proc/asound/cards'

  3. all messages from /var/log/messages which should be relevant to
     ALSA driver

  4. problem description


  6.6.  Tip: playing CD's

  If you use kmod/kerneld and the ALSA drivers to play CD's, then
  kmod/kerneld probably do not load the drivers as expected. This is due
  to the fact that a command line CD player only tells the CD player to
  start playing without using any of the devices that tell kmod/kerneld
  that there is sound to occur. Using modprobe may be your only solution
  to this problem.


  6.7.  Tip: installing the MIDI serial driver

  Normally, the IO port of the serial device is owned by the standard
  serial device driver. So before you can do ``modprobe snd-serial'' we
  have to tell the driver to release the serial device.

  Here is the procedure.



       setserial /dev/ttyS0 uart none
       modprobe snd-serial




  (Replace /dev/ttyS0 with the appropriate /dev/ttySx device if your
  MIDI device uses a different serial device).


  6.8.  Tip: new kernel? New modules!

  After you upgrade your kernel, you probably need to recompile the ALSA
  drivers. If they are still in the original /usr/src directory, then
  please do not forget to issue a make clean before you do the
  ./configure, make, make install thing.

  Oh, and then there is this anomaly in kernel numbering: a ``2.2.0ac1''
  kernel that is ``not a number'' - says the configure script. I think
  this was resolved in newer scripts, otherwise you should maybe change
  the kernel version in the source.


  6.9.  Tip: KDE and ALSA drivers

  Suppose you have KDE up and running but you cannot get system sounds
  to work, like for opening windows, changing desktops, etc. Sound works
  in general.  If your cd player and mp3 player and mixer all do work,
  then it's probably just "kwmsound" that's lacking.

  So: make sure "kwmsound" is in your startscript ($KDEDIR/bin/startkde)


  6.10.  Tip: use the ALSA devices

  If you had sound support in your Linux before, then your applications
  will probably all point to /dev/pcm0, /dev/audio and /dev/mixer. This
  is fine, if you use OSS compatibility with the snd-pcm1-oss module. It
  might be better, however, to use the real ALSA devices, those found in
  /dev/snd/.


  6.11.  Tip: removing all modules

  Removing 10+ modules one by one is not the way to go. Luckily, all
  modules start with the "snd-" prefix, so a little command line
  programming will do.  You can easily remove ALSA sound by issuing a
  command like:



       cat /proc/modules|gawk '/^snd-/{print $1}|xargs -i rmmod {}




  Juergen Kahrs wrote: ``I have a script that also removes soundcore and
  soundlow and sound if present and if they are not in use. This script
  processes /proc/modules three times so there should not be too many
  modules left after processing''. His solution is



       awk '/^snd/||/^sound/&&($3==0){system("rmmod " $1)}' /proc/modules /proc/modules /proc/modules




  Please note: if some module is dependent on another module you cannot
  just remove the "higher" one.  This means that you might need to issue
  a second removal statement. (I never encountered this situation
  though, it seems that you can remove the ALSA modules in the order
  they appear in /proc/modules).










