[pulseaudio-discuss] Why does Jack section uses "state.plugged = unknown" and "state.unplugged = unknown"?

[Chengyi Zhao]

Hi guys,

I don't know why Jack section uses "state.plugged = unknown" and 
"state.unplugged = unknown" in the path file 
"analog-output-lineout.conf" below.

I think PulseAudio should set Jack to be available when it recognizes 
the "Jack Line Out CLFE" is plugged, and vice versa.

Would you please help explain the true meaning of ”unknown“ here.

[Jack Line Out CLFE]
state.plugged = unknown
state.unplugged = unknown
required-any = any

Best Regards,
Chengyi