Category: kernel
Synopsis: Internal microphone not working on ThinkPad T490 (Realtek ALC257 /
Intel SST)
Description: Internal microphone produces no audio on ThinkPad T490 running
OpenBSD 7.9. kern.audio.record=1, all mixer settings correct, all record
channels unmuted. Recording produces files with Maximum amplitude 0.000000. The
internal mic is routed through Intel Smart Sound Technology (SST), not the
azalia HD audio codec. OpenBSD has no driver for Intel SST.
How-To-Repeat: sox -t sndio default test.wav trim 0 3 && sox test.wav -n stat
shows Maximum amplitude 0.000000
Fix: Driver needed for Intel Smart Sound Technology (SST) chip.
Hardware: Lenovo ThinkPad T490, azalia0 codecs: Realtek ALC257, OpenBSD 7.9
amd64
