Headphones not detected at startup

[Andrew Tribick]

The headphones are not detected if they are plugged in before the system starts up. To get sound out of my headphones, I need to unplug the headphones and plug them back in again. After this, sound is sent to the headphones.

Reproducible: always

Steps to reproduce:
1. Plug in headphones
2. Switch on computer, log into Kubuntu
3. Attempt to play sound in any application, no sound produced.
4. Unplug and replug headphones
5. Sound works

Expected behaviour:
At step 3, sound should be output through the headphones.

The problem seems to be in alsamixer: when starting Kubuntu the headphone volume is set to zero and the headphones are muted. Re-plugging the headphones will unmute the headphones in alsamixer and set to an audible volume.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: ubuntu-release-upgrader-core 1:15.10.14.1
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: KDE
Date: Sun Nov 1 19:43:09 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-10-31 (1 days ago)
InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)

[Andrew Tribick (ajtribick)]

Found the problem seems to be in alsamixer: updated description.

[Andrew Tribick (ajtribick)]

Further investigation - this seems to be because I am running with a separate /var partition and the alsa systemd services are being started before the /var partition is mounted.

I have tried altering my fstab to include the x-initrd.mount option as suggested at http://superuser.com/a/841748 on the /var partition (so the options end up being defaults,x-initrd.mount) but this appears to prevent the partition from being loaded altogether. Searching for this brought up a Red Hat bug: https://bugzilla.redhat.com/show_bug.cgi?id=1249513 - not sure if Kubuntu 15.10 would be affected by that?

[Andrew Tribick (ajtribick)]

Underlying issue appears to be fixed now. No regression on upgrade to Xenial.