Alsa Sound support for HDMI audio passthrough using an Nvidia EN210

This is probably a common problem among all the people trying to get audio over HDMI under Linux using an EN210 graphics card (or similar).

Even though the HDMI may appear in your available cards listed in proc (/proc/asound/cards) you will probably see that you cannot find it using the aplay utility. Just check it running the command “aplay -l”. The HDMI device isn’t listed here isn’t it?

The reason for this issue is related to the ALSA driver version 1.0.21 (or older) which is quite buggy for these graphics cards.

You can check which version you are using by executing the following command:

cat /proc/asound/version

If you get a version older than 1.0.21 then you need to upgrade it. You can check your favourite distribution’s repository for an update or you can try to compile it from source code.

If you can’t find an update, check this page: http://ubuntuforums.org/showthread.php?t=1681577

It might help you ;-)

Problems using nvidia drivers under Ubuntu

After upgrading my HTPC to Ubuntu 10.04, nvidia drivers stopped working without any reason. After googling a bit, all the answers pointed to a problem related with Ubuntu upgrade system not updating restricted drivers. I have tried manually to update and use all the available versions, but without any success…until I found the cause and solution.

It happens that Ubuntu does not remove old drivers correctly, leaving you with multiple versions which were confusing the operating system. The solution was to purge the system from all nvidia drivers and reinstall just one of them.

You can run the following commands to clean the system:

sudo dpkg --get-selections | grep nvidia | grep -v deinstall | awk '{print $1}' | xargs sudo apt-get remove -y
sudo apt-get install nvidia-current
sudo nvidia-xconfig

sudo reboot

The system will then reboot and if everything is OK, Ubuntu will be as good as new.