Comment 17 for bug 871582

Ok, so there is indeed some improvement. That's good. Now for the automute - which I understand is the remaining problem? - here's what *should* be happening:

Look at /proc/asound/SB/codec#0

Node 0x14 is the front line out. Whenever you plug headphones in, the "OUT" status should turn off, and then it should be turned on again when you unplug. That should then mute/unmute the line out. Like this:

Node 0x14 [Pin Complex] wcaps 0x40058d: Stereo Amp-Out
  Control: name="Front Playback Switch", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-Out caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
  Amp-Out vals: [0x00 0x00]
  Pincap 0x0001003e: IN OUT HP EAPD Detect Trigger
  EAPD 0x2: EAPD
  Pin Default 0x01014010: [Jack] Line Out at Ext Rear
    Conn = 1/8, Color = Green
    DefAssociation = 0x1, Sequence = 0x0
  Pin-ctls: 0x40: OUT <----------------------------------------- Headphones not plugged in, OUT present
  Unsolicited: tag=00, enabled=0
  Power states: D0 D1 D2 D3
  Power: setting=D0, actual=D0
  Connection: 1
     0x0c

Node 0x14 [Pin Complex] wcaps 0x40058d: Stereo Amp-Out
  Control: name="Front Playback Switch", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-Out caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
  Amp-Out vals: [0x00 0x00]
  Pincap 0x0001003e: IN OUT HP EAPD Detect Trigger
  EAPD 0x2: EAPD
  Pin Default 0x01014010: [Jack] Line Out at Ext Rear
    Conn = 1/8, Color = Green
    DefAssociation = 0x1, Sequence = 0x0
  Pin-ctls: 0x00: <------------------------------------------------------- Headphones plugged in, "OUT" is now disabled from line out
  Unsolicited: tag=00, enabled=0
  Power states: D0 D1 D2 D3
  Power: setting=D0, actual=D0
  Connection: 1
     0x0c

Also ensure "Automute mode" is set to "Enabled" in alsamixer.