if your ao722 really support headset mic
for example if the value of node 0x1b change to yes when you plug the external mic, change the sequence of node 0x1a to 0x0d
http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=cb420b1186e0090f24137855e14e6f3bf7cb769d
if your ao722 really support headset mic
for example if the value of node 0x1b change to yes when you plug the external mic, change the sequence of node 0x1a to 0x0d
http:// git.kernel. org/cgit/ linux/kernel/ git/tiwai/ sound.git/ commit/ ?id=cb420b1186e 0090f24137855e1 4e6f3bf7cb769d