[Dell Latitude 3340] Microphone mute key does not work

[Po-Hsu Lin]

CID: 201312-14381 Dell Latitude 3340

The Microphone mute on this system is not working

Steps:
1. Install 14.04 + update (3.13.0-27 #50)
2. Speak to the mic and record it, test the mic mute key to see if it works (fn+f4)

Expected results:
* Mic mute key should work, and the "Mute" option for input device should be ticked after you press the mic mute key

Actual result:
* Nothing happened

Debugging information:
From sudo showkey -k, keycode 248 press and release would be detected, when you press the mic mute combination key.
From xev, this event cannot be detected.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-27-generic 3.13.0-27.50
ProcVersionSignature: Ubuntu 3.13.0-27.50-generic 3.13.11
Uname: Linux 3.13.0-27-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: ubuntu 1552 F.... pulseaudio
 /dev/snd/pcmC1D0c: ubuntu 1552 F...m pulseaudio
 /dev/snd/controlC0: ubuntu 1552 F.... pulseaudio
CurrentDesktop: Unity
Date: Thu Jun 5 03:52:08 2014
HibernationDevice: RESUME=UUID=3a9169b0-e941-485e-9aac-c369d2a231a3
InstallationDate: Installed on 2014-06-05 (0 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: Dell Inc. Latitude 3340
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-27-generic.efi.signed root=UUID=cbf67c96-d451-43fe-9d3b-27a3d278397e ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-27-generic N/A
 linux-backports-modules-3.13.0-27-generic N/A
 linux-firmware 1.127.2
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/24/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A00
dmi.board.name: 4OA010
dmi.board.vendor: Dell Inc.
dmi.board.version: D01
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA00:bd12/24/2013:svnDellInc.:pnLatitude3340:pvr01:rvnDellInc.:rn4OA010:rvrD01:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude 3340
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

[Po-Hsu Lin (cypressyew)]

verified with the daily mainline kernel
3.15.0-999-generic_3.15.0-999.201406050226_amd64.deb
this issue still exist.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Po-Hsu Lin (cypressyew)]

Also affects 201312-14380 Dell Latitude 3340

[Hui Wang (hui.wang)]

To solve this problem, we need to add a udev keyboard rule.

We already have a package, please access it at: lp:~oem-solutions-group/kittyhawk/dell-mic-mute-keycode-workaround-1301855.fix