The problem seems to be related to the IOMMU. With kernel 5.10.0-16-amd64:
intel_iommu=off: sound and video both working intel_iommu=on,intgpu_off (Debian default): video working, sound broken intel_iommu=on: sound and video both broken With kernel 4.19.0-21-amd64: intel_iommu=off (Debian default): sound and video both working intel_iommu=on,igfx_off: video working, sound broken intel_iommu=on: sound working, video broken So a workaround is to set 'intel_iommu=off' on the kernel command line. However, given that the old driver (snd-soc-sst-haswell-pcm) works with 'intel_iommu=on', perhaps this can be fixed for the new driver (snd-soc-catpt) as well.
