These patches implement UAC2 jack detection.
This allows USB-to-3.5mm adapters and similar USB devices to report jack state via alsa control, using the reporting provided by the UAC2 connector control.
The second patch updates the clock validity control so it doesn't show up in mixer UIs.
I declined to mark the controls as VOLATILE since clients should always be notified of changes, since UAC devices are expected to generate interrupt messages when a control value changes.
v2 changes: - use SNDRV_CTL_ELEM_IFACE_CARD instead of _MIXER - correct channel count to 1, cmask to 0. - add validity patch.
Andrew Chant (2): ALSA: usb-audio: UAC2 jack detection ALSA: usb-audio: update clock valid control
sound/usb/mixer.c | 117 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 109 insertions(+), 8 deletions(-)