Jack functions numbered as seen in Asus PDF, copied from Realtek HDA: Jack 1: Headphone Front Speaker Out
Jack 2: Mic In Center/Subwoofer Speaker Out
Jack 3: Headphone Rear Speaker Out
On Windows I don't need any reboot. hdajackretask was giving a warning and it didn't work only after rebooting.
Have you tested whether your dual headphone jacks work as expected ?
When auto parser find two headphone jacks and no line out jacks, it use sequence number to check those headphone and dock headphone and put one headphone jack in spec->line_out_pins
But your dual headphone jacks need sequence number to determine whether it is use as headphone for front and headphone for surround
http://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/src/modules/alsa/mixe...
AFAIK, no alsa driver create Headphone2 playback volume nor Headphone2 playback switch controls