On 2026/10/05 15:52, Stefano L wrote: > Internal microphone on ThinkPad T490 (azalia0, Realtek ALC257) records > silence. Playback works. > > How to repeat: run aucat -o /tmp/mic.wav, speak, stop with Ctrl-C, play back > with aucat -i /tmp > /mic.wav. The recording is silent. Same result with the headphone jack > unplugged. > > State: kern.audio.record=1, input.mute=0, input.level=1.000, > inputs.mic=255,255, > record.adc-0:1_source=mic, record.adc-2:3_source=mic2,mic, > record.adc-4:5_source=mic2, > outputs.mic2_sense=unplugged. > > Same laptop records correctly on Debian. FreeBSD shows the same silence, > reported as FreeBSD > bug 296398, which describes the internal microphone as digital. I have not > verified that on > OpenBSD. > > >
I think that this may require DSP firmware, and if so Debian is likely to be using soundopenfirmware (https://sofproject.org/) for it. OpenBSD doesn't support this.
