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control.14 { iface CARD name 'Mic Jack' value false comment { access read type BOOLEAN count 1 } }

What is the usage of this jack detect control if conventional mic is not supported ?

"jack detect" reads like "detect if something is present", and that is overly general, which could also mean it is used to detect when to turn off the built-in speaker.

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc...

Seem those dock stations also have combo jack but the patch did not create dock headset mic jack / dock headset mic phantom jack

ThinkPad® Ultra Dock(40A20090XX), ThinkPad® Pro Dock (40A10065XX), ThinkPad® Dock (40A00065)

http://support.lenovo.com/en/documents/pd028010

http://support.lenovo.com/en/documents/pd028011

1x Stereo/Mic Combo Audio Port

Refer to the maunal of those dock station, the icon near the combo jack is also a headset