Mic mute hotkey support

Registered by David Henningsson

Several new computers have a hotkey for muting / unmuting the Microphone. We don't have proper support for this in Ubuntu - it needs support in the kernel, in gnome-settings-daemon, and possibly other places.
It would be nice to do this the right way in Oneiric as we're currently hacking around it with custom scripts.

Blueprint information

Status:
Not started
Approver:
Chris Van Hoof
Priority:
Medium
Drafter:
David Henningsson
Direction:
Needs approval
Assignee:
None
Definition:
New
Series goal:
Proposed for precise
Implementation:
Deferred
Milestone target:
None

Related branches

Sprints

Whiteboard

== Current Status ==
* This blueprint is being deferred to the P Series as there is still work to be done in the way of a standardized LED definition, and the userspace plumbing to support this hotkey.

== Notes ==
* KEY_MICMUTE added to the 3.0 kernel: http://www.spinics.net/lists/ibm-acpi-devel/msg02614.html
* Mic mute LED definition proposed, but no recent updates: http://comments.gmane.org/gmane.linux.drivers.platform.x86.devel/1962
  * Tested the above two patches on top of 2.6.38-10: http://kernel.ubuntu.com/~sarvatt/thinkpad/
    * /sys/devices/platform/thinkpad_acpi/leds/tpacpi::micmute/brightness is now exposed and functions on a x220
    * NOTE: The mic mute LED does not work on X220 Tablet even with the patch mentioned above.
    * Pressing the mic mute hotkey is no longer an undefined event
* Will still require work to identify how to to make use of one of X's 248 keycodes
* Will still require userspace plumbing support in g-s-d to show a notification, and also interact with PulseAudio

Work items:
[diwic] Outine required userspace plumbing required to handle this key press reliably: DONE
[vanhoof] Test KEY_MICMUTE and initial LED support patch on x220 to verify functionality: DONE
Investigate how the mic mute LED definition will be handled in the long-term upstream: POSTPONED
Sort out how to implement via one of X's 248 keycodes (to include upstream): POSTPONED
Implement support in gnome-settings-daemon to to show a OSD notification: POSTPONED
Implement support in gnome-settings-daemon to allow it to talk to PulseAudio when events are received: POSTPONED

Status (2011-09-06): Due to lack of time (and that both I and vanhoof forgot about it) this won't reach Oneiric. Postponing.

(?)

Work Items

Dependency tree

* Blueprints in grey have been implemented.

This blueprint contains Public information 
Everyone can see this information.