Comment 14 for bug 1228689

in patch_realtek.c

there is a snd_pci_quirk_vendor for all sony vaio to use ALC269_FIXUP_SONY_VAIO

static const struct hda_fixup alc269_fixups[] = {
 [ALC269_FIXUP_SONY_VAIO] = {
  .type = HDA_FIXUP_PINCTLS,
  .v.pins = (const struct hda_pintbl[]) {
   {0x19, PIN_VREFGRD},
   {}
  }
 },

 SND_PCI_QUIRK(0x104d, 0x9073, "Sony VAIO", ALC275_FIXUP_SONY_VAIO_GPIO2),
 SND_PCI_QUIRK(0x104d, 0x907b, "Sony VAIO", ALC275_FIXUP_SONY_HWEQ),
 SND_PCI_QUIRK(0x104d, 0x9084, "Sony VAIO", ALC275_FIXUP_SONY_HWEQ),
 SND_PCI_QUIRK_VENDOR(0x104d, "Sony VAIO", ALC269_FIXUP_SONY_VAIO),

>> AFAIK the SONY has two microphones onboard.

do you mean the left and right channels are in inverted phase ?

if yes, try mute the right channel of Capture Switch

Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 127
  Front Left: Capture 127 [100%] [30.00dB] [on]
  Front Right: Capture 127 [100%] [30.00dB] [off]

usually the laptop use either pin sense of headphone jack or mic jack to detect the headset instead of both

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/log/sound/pci/hda?qt=grep&q=headset+mic