> So, my conclusion is that there is something specific to the debian kernels that is breaking this USB ethernet card. The IOMMU error is most likely caused by a bug in the VL805 firmware. It happens with the Debian kernel (and not mainline) as Debian patches the kernel to enable IOMMU by default. The updated VL805 firmware apparently fixes the bug, it can be installed using the VIA Windows tool (this did not work for me), or you can just turn off IOMMU.