With the correct tweak:
options snd-hda-intel model=,dell-headset-multi
added into /etc/modprobe.d/alsa-base.conf
Input source will change form "Analog input" to "Internal Microphone"
And with external headset plugged, two more options "Headset Microphone" and "Microphone" will be available, and the external microphone works with "Headset Microphone" selected
With the correct tweak: dell-headset- multi d/alsa- base.conf
options snd-hda-intel model=,
added into /etc/modprobe.
Input source will change form "Analog input" to "Internal Microphone"
And with external headset plugged, two more options "Headset Microphone" and "Microphone" will be available, and the external microphone works with "Headset Microphone" selected