Alsa Sound mini-HOWTO

Alsa Sound mini-HOWTO
Valentijn Sessink
v0.0, 8 February 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 Troubleshooting: activation of the driver
6.1.1 Linux kernel sourcetree
6.1.2 OSS/Linux compatibility
6.1.3 Sound card compatibility
6.1.4 OSS/Lite or kernel-driver
6.1.5 Check the PnP setup
6.1.6 Are your parameters right?
6.1.7 Try using ``insmod''
6.1.8 Read the INSTALL file.
6.1.9 Debug messages
6.1.10 If all else fails...
6.2 Bug reports
6.3 Tip: playing CD's
6.4 Tip: new kernel? New modules!
6.5 Tip: KDE and Alsa drivers
6.6 Tip: use the Alsa devices
6.7 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.

1.2. Revision History

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

Version 0.2 alpha - mid januari 1999, first .sgml-version.

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

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

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.

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://huizen.dds.nl/~valentyn

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

Miod Vallat will work on a French translation - I'll include the URL
here as soon as I know it.

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
([email protected]), 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 coordinator, Tim Bynum [email protected], 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 proved to work. I have only x86 PC's here,
so any additional info is 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. It has evolved
to 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://alsa.jcu.cz/intro.html

The main page of the Alsa project is http://alsa.jcu.cz/

2.3. Supported hardware

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

� 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/AWE, PCI64

� ESS AudioDrive ESx688

� ESS ES18xx (chipsets)

� 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 (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 accross while trying to install the Alsa drivers. HOWTO's can,
generally, be found at mirrors of sunsite. So take a look at
http://sunsite.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 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 can make this HOWTO
up to date with the 2.2 series.

2.4.1. Sound cards

Perhaps you bought a sound card already, or maybe it's stuck down
there 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, and 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 reasonably
recent Linux distribution includes these. 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 info 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://alsa.jcu.cz/pub/, and there
is a mirror at ftp://linux.a2000.nl/alsa For a fully functional Alsa-
installation, you need the driver, the libs and the utilities; for
example, if you chose the mirror you would get
ftp://linux.a2000.nl/alsa/driver/alsa-driver-0.2.0-pre10p3.tar.gz,
ftp://linux.a2000.nl/alsa/lib/alsa-lib-0.3.0pre2.tar.gz and
ftp://linux.a2000.nl/alsa/utils/alsa-utils-0.0.8.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-0.2.0-pre10p3.tar.gz

(If this worked you either are 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
rootprivs for. So: for this, you need rootprivs, type a "su" and the
password).
tar -zxf ~/alsa-lib-0.3.0pre2.tar.gz

tar -zxf ~/alsa-utils-0.0.8.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-0.2.0-pre10p3

(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

./configure

make

make install

OK, you're getting it, the utilities:

cd ../alsa-utils-0.0.8

./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 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 about backward compatibility (the last
section of this paragraph. I did not find out how to use links inside
a .sgml document yet). 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. 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, 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 any�
thing 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 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

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/#/mixer0, where <file> was obtained from
/proc/asound/#/mixer0. I have not been able to reproduce this, 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/pcm00 - the raw audio device for the card
/dev/snd/mixer0 - the mixer for card 0
/dev/snd/control0 - 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 pcm00 and pcm01 device.

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/pcm00, like this: cat <filename> > /dev/snd/pcm00. 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 telling 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/pcm00 -> /dev/audio0 (/dev/audio) -> minor 4
/dev/snd/pcm00 -> /dev/dsp0 (/dev/dsp) -> minor 3
/dev/snd/pcm01 -> /dev/adsp0 (/dev/adsp) -> minor 12
/dev/snd/pcm10 -> /dev/audio1 -> minor 4+16 = 20
/dev/snd/pcm10 -> /dev/dsp1 -> minor 3+16 = 19
/dev/snd/pcm11 -> /dev/adsp1 -> minor 12+16 = 28
/dev/snd/pcm20 -> /dev/audio2 -> minor 4+32 = 36
/dev/snd/pcm20 -> /dev/dsp2 -> minor 3+32 = 39
/dev/snd/pcm21 -> /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
depends on the application you use to play sound. Regular sound
playing application, 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. Troubleshooting: activation of the driver

Please check the following items.

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.

6.1.2. OSS/Linux compatibility

If you want to use sound exactly as you did before (i.e. use the
/dev/pcmX devices), then you need the ``OSS compatibility driver''. 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.

6.1.3. 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
waisting 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.

6.1.4. OSS/Lite or kernel-driver

You might have a 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).

I will say this again, since it is the cause of many troubles: you
should NOT have sound support compiled into the kernel, and you should
NOT have a ``sound.o'' module active. (The Alsa ``snd.o'' is OK,
though).

6.1.5. 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.

6.1.6. Are your parameters right?

Check, doublecheck your sound card parameters. And 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).

6.1.7. Try using ``insmod''

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

6.1.8. 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.

6.1.9. 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.

6.1.10. If all else fails...

If these messages doesn't help you, send a message to the Alsa
developers mailing list, [email protected]. Include the following
information:

� soundcard name + chip names present on your soundcard

� 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

6.2. 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

6.3. 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.

6.4. 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.

6.5. 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)

6.6. 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/.

6.7. 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 {}

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).