UpdateAudioDriver

Update the audio driver

Introduction

Patch the Realtek audio module to correctly identify the AppleTV audio hardware and enable analog (rca) output. Audio over HDMI is not supported at the current time.

Details

This involves patching the existing linux-ubuntu-modules-2.6.22-2.6.22 install, so remember that if you allows this to be updated in the future, you will have to reapply this patch. Thanks to Jason (SredniV in the MythBuntu forums) for figuring out the deb part.

# get some build tools
sudo apt-get install fakeroot kernel-wedge

# move to the standard location for kernel source
cd /usr/src
# get the source code for the current ubuntu modules
sudo apt-get source linux-ubuntu-modules-2.6.22-14-generic
cd /usr/src/linux-ubuntu-modules-2.6.22-2.6.22/ubuntu/media/snd-hda-intel

# patch patch_realtek.c
# download the patch
sudo wget http://atv-bootloader.googlecode.com/files/atv-realtek-rca-audio-r2-2.6.22-14-generic.patch
# first, check the patch for errors
sudo patch --dry-run < atv-realtek-rca-audio-r2-2.6.22-14-generic.patch
# if no errors then apply the patch
sudo patch < atv-realtek-rca-audio-r2-2.6.22-14-generic.patch

# back to the level of the module deb source
cd ../../..

# rebuilt the modules
sudo fakeroot debian/rules binary-arch arch=i386 flavours="generic"

# the build will end with the following error, that's ok
dpkg-deb: --extract needs a target directory.
Perhaps you should be using dpkg --install ?
make: *** [binary-udebs] Error 2

# up one more level to where the deb is placed 
cd ..
sudo dpkg --install linux-ubuntu-modules-2.6.22-14-generic_2.6.22-14.37_i386.deb

# dpkg --install should rebuild the initramfs but some 
# users seem to require a manual rebuild of the initramfs
sudo update-initramfs -u

# the change takes effect on the next reboot and you should see
dmesg | grep hda_codec
hda_codec: Detected AppleTV RealTek Subsystem ID