Created attachment 299749 attachment-3712-0.html Without the patches, I'm missing: /sys/devices/pci0000:00/0000:00:15.2/i2c_designware.2/i2c-3/i2c-CLSA0101:00 With the patches, I'm missing: /sys/kernel/btf/snd_hda_codec_cs35l41_i2c /sys/kernel/btf/snd_soc_cs35l41_i2c /sys/kernel/btf/snd_soc_cs35l41_spi /sys/module/snd_pcm/holders/snd_soc_cs35l41_i2c /sys/module/snd_pcm/holders/snd_soc_cs35l41_spi snd_pcm is compiled directly in though, and the btf stuff appears related to debugging options I don't have enabled. Seems that for where it matters, our related kernel options are identical. I don't have any NULL pointer dereferences. Also, it seems there's been a new BIOS release since early September. I doubt it, but I wonder if would make any difference. I'm hesitant to try it in case if makes a permanent upgrade related to the amp chips that would completely break my sound. Here's the BIOS info I have (from lshw): version: H1CN33WW          date: 07/18/2021 On 11/27/21 07:42,