Do you mean
LOUT1 playback volume control at node 0x8 affect the volume of your headphone and LOUT2 playback volume control at node 0x9 affect the volume of your speakers ?
If you look at 4.1 Block Diagram of alc260 datasheet ,
LOUT1 is connected to 0xf Line Out and LOUT2 is connected to 0x10 HP
Having looked at the datasheet I agree with you, this seems surprising. However, if I run speaker-test and then toggle the mutes of LOUT1 and LOUT2 one by one, they toggle the headphones and speakers respectively.
Additionally, to hear output on each device I have to set the following pin modes:
Headphones: LINE1 pin mode at node 0x14 must be set to line out (quieter)/headphones (louder) Speakers: HP-OUT pin mode at node 0x10 must be set to line out/headphones (same volume)
This bears little relationship to the datasheet.
_From the datasheet it looks like:
Node 0x1b [Volume Knob Widget] wcaps 0x600080: Mono Volume-Knob: delta=0, steps=64, direct=0, val=48 Unsolicited: tag=00, enabled=0 Connection: 0
should be responsible for the jack detection. I have noticed in my testing that the "val" is sometimes 48 and sometimes 49, but I haven't been able to correlate this with presence of headphones or otherwise.