Bug#1014299: linux-image-5.10.0-15-amd64: No audio on Thinkpad Helix 2 (broadwell-rt286); "firmware ready timeout"

[Benjamin Moody <benjamin.moody@gmail.com>]

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.