Comment 12 for bug 1315911

seem need to change pin default from 0x03a11040 to 0x03a114c

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda/patch_realtek.c?id=73bdd597823e2231dc882577dbbaf8df92fe1775

+ [ALC668_FIXUP_DELL_MIC_NO_PRESENCE] = {
+ .type = HDA_FIXUP_PINS,
+ .v.pins = (const struct hda_pintbl[]) {
+ { 0x19, 0x03a1913d }, /* use as headphone mic, without its own jack detect */
+ { 0x1b, 0x03a1113c }, /* use as headset mic, without its own jack detect */
+ { }
+ },
+ .chained = true,
+ .chain_id = ALC668_FIXUP_HEADSET_MODE
+ },

Node 0x1b [Pin Complex] wcaps 0x40048b: Stereo Amp-In
   Control: name="Mic Boost Volume", index=0, device=0
     ControlAmp: chs=3, dir=In, idx=0, ofs=0
   Control: name="Mic Jack", index=0, device=0
   Amp-In caps: ofs=0x00, nsteps=0x03, stepsize=0x27, mute=0
   Amp-In vals: [0x03 0x03]
   Pincap 0x00003724: IN Detect
     Vref caps: HIZ 50 GRD 80 100
   Pin Default 0x03a11040: [Jack] Mic at Ext Left
     Conn = 1/8, Color = Black
     DefAssociation = 0x4, Sequence = 0x0
   Pin-ctls: 0x24: IN VREF_80
   Unsolicited: tag=02, enabled=1
   Power states: D0 D1 D2 D3 EPSS
   Power: setting=D0, actual=D0