How to get a patched alsa kernel module installed on your Linux system
----------------------------------------------------------------------

This document describes how you can build and install a patched Linux alsa
kernel module on a Debian GNU/Linux (or Ubuntu) system.  You need this if
stock alsa does not support your sound card or microphone.

Suppose your hacked alsa-driver sources are in alsa-driver-1.0.23-5.15rc21-1.tar.bz2.
Unpack this tarball:

 $ tar jxf alsa-driver-1.0.23-5.15rc21-1.tar.bz2

Next to these patched sources, get the sources as used by Debian:

 $ apt-get source alsa-source

Now, Debian's sources are in alsa-driver-1.0.23+dfsg, our hacked sources are in
alsa-driver-1.0.23.  We "steal" the Debian packaging:

 $ mv alsa-driver-1.0.23+dfsg/debian alsa-driver-1.0.23/
 $ cd alsa-driver-1.0.23

(NB: This is a very crude way to Debianize our initial tarball.  It only works
as long as Debian's own patches for the alsa-driver code do not conflict with
our.  We're lucky this time: the patches in alsa-driver_1.0.23+dfsg-2's
debian/patches are ok for us.  Furthermore, extracting a nice patch from our
tarball and adding that to debian/patches/ and debian/PATCHES.Debian would be
The Right Way to do it.  Since this is a local package, we choose the quick and
dirty approach.)

Update the version, to reflect our changes:

 $ dch -l local "Added patch which does foo."

Build our Debianized patched sources:

 $ debuild -us -uc

This yields in directory .. :

 alsa-base_1.0.23-5.15rc21-1-0local1_all.deb           alsa-driver_1.0.23-5.15rc21-1-0local1_i386.changes
 alsa-driver_1.0.23-5.15rc21-1-0local1.debian.tar.bz2  alsa-source_1.0.23-5.15rc21-1-0local1_all.deb
 alsa-driver_1.0.23-5.15rc21-1-0local1.dsc             linux-sound-base_1.0.23-5.15rc21-1-0local1_all.deb
 alsa-driver_1.0.23-5.15rc21-1-0local1_i386.build

NB: The kernel modules have not been build yet.  Only the part which is
independent of the specific kernel version has been build.

Install these packages:

 # dpkg -i *.deb

NB: Among others, we installed alsa-source_1.0.23-5.15rc21-1-0local1_all.deb.
This "binary" package contains the C source code; it installs these sources in
/usr/src/alsa-driver.tar.bz2 .

 # m-a update

Check wether module-assistant knows about our new package:

 # m-a list alsa

Our version should show up.

 # m-a build alsa

This yields
alsa-modules-2.6.32-5-686_1.0.23-5.15rc21-1-0local1+2.6.32-44_i386.deb.  It
contains kernel modules like:

 /lib/modules/2.6.32-5-686/updates/alsa/acore/snd.ko
 /lib/modules/2.6.32-5-686/updates/alsa/pci/hda/snd-hda-codec-realtek.ko
 /lib/modules/2.6.32-5-686/updates/alsa/pci/hda/snd-hda-intel.ko

Install it:

 # dpkg -i /usr/src/alsa-modules-2.6.32-5-686_1.0.23-5.15rc21-1-0local1+2.6.32-44_i386.deb

Now run alsamixer to adjust your settings.  Press F5 so that both soundcards
_and_ microphones are shown.

Does it work?
-------------

Test the soundcard by running

 $ aplay /usr/share/sounds/alsa/*.wav

Test the microphone by running

 $ arecord -v -v /tmp/sound.wav

Make some sound.  Press ^C.  Listen to the recording:

 $ aplay /tmp/sound.wav


Author, copyright
=================

Copyright (C) 2012 Joost van Baal-Ilić <joostvb-debian-m-a-2191@mdcc.cx>

Redistribution and use, with or without modification, are permitted provided
that the above copyright notice, this condition and the following disclaimer
are retained.

This work 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.

# http://git.mdcc.cx/ad1810-doc.git