Sorry, i’ve been troubleshooting the hat driver using infineon’s git build instructions on pi zero, pi 3B+ and p i4. Which all fail with the same issue. The HAT was on a pi 3B+ . I decided to try another image - yours - and got precisely the same dmesg errors reported on your build. I will move the HAT to a zero and expect volumio will work there. Again, sorry - I didn’t read the fine print for volumio hardware. Basically the problem I am chasing is a probe failure on the codec which prevents instantiation of the merus driver.