There are two reasons for this change:
1. If it is a Dell desktop machine with the realtek codec, and there is no internal microphone on it, there is one physical audio jack which can support headphone, headset and microphone, but this audio jack does not have hardware capability to distinguish what is plugged in, after users plug in a headphone and select headphone from UI program, the headphone can't output any sound. There are many reasons for this issue, one of them is the active_port of pa_source is set to headphone-mic, that means the kernel audio driver will configure this audio jack to be a microphone jack instead of headphone jack. If we make the priority of headset-mic a bit higher than headphone-mic, the headset-mic will be the active_port of pa_source unless users select the headphone-mic on purpose, then this issue will be fixed.
2. Nowadays, the headset is more popular than traditional microphone, It is highly possible that users plug in a headset instead of microphone, it makes sense to make the headset-mic's priority higher than headphone-mic's.
e3b64d8 alsa: make priority of the port headset-mic higher than headphone-mic
src/modules/alsa/mixer/paths/analog-input-headset-mic.conf | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)