The Xillybus Forum

Hi, I'm using Xillinux on a Zedboard and have the problem that any input on line in is looped out to line out and headphone. I need to process the line in signal and output again, so how do i disable the loopback?

thanks and best regards,
viktor

Hello,

Loopbacks can occur at two levels, in principle: Directly by the audio chip or in software.

It's easy to check on the latter: Turn off pulseaudio (with "pulseaudio --kill" and verify that the /dev/xillybus_audio file can be written to directly, so it's not taken by Pulseaudio). If loopback still exists, it's by the audio chip.

In this case, you need to set up its registers to disable the loopback. I suggest taking a look on /usr/local/bin/zedboard sound setup.pl, which is where the default values are set.

Regards,
Eli