When sound breaks (bug #1950533), sound input device breaks worse.

[Benjamin Button]

What I expect to happen: I can use my USB webcam mic when an important remote meeting takes place.

What happens instead: After triggering bug #1950533, microphone is present in Gnome sound settings and pavucontrol, but registers no sound, until I reboot and plug the webcam into a different USB port. For a few months (and before I knew how to address the issue), the only way I knew this had occurred was by entering a Zoom meeting and being unable to communicate.

I was not able to replicate the issue on the installation with which I reported
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1950533
so I filed this part of the bug using ubuntu-bug separately.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: firefox 94.0+build3-0ubuntu0.20.04.1
ProcVersionSignature: Ubuntu 5.11.0-40.44~20.04.2-generic 5.11.22
Uname: Linux 5.11.0-40-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: username 4638 F.... pulseaudio
 /dev/snd/controlC2: username 4638 F.... pulseaudio
 /dev/snd/controlC0: username 4638 F.... pulseaudio
BuildID: 20211028161635
CasperMD5CheckResult: skip
Channel: Unavailable
CurrentDesktop: ubuntu:GNOME
Date: Wed Nov 10 21:23:26 2021
DefaultProfileExtensions: extensions.sqlite corrupt or missing
DefaultProfileIncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
DefaultProfileLocales: extensions.sqlite corrupt or missing
DefaultProfilePrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:363
DefaultProfileThemes: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
InstallationDate: Installed on 2021-10-10 (31 days ago)
InstallationMedia: Ubuntu 20.04.3 LTS "Focal Fossa" - Release amd64 (20210819)
IpRoute:
 default via 192.168.1.1 dev enp3s0 proto dhcp metric 100
 169.254.0.0/16 dev enp3s0 scope link metric 1000
 192.168.1.0/24 dev enp3s0 proto kernel scope link src 192.168.1.152 metric 100
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Profile0Extensions: extensions.sqlite corrupt or missing
Profile0IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
Profile0Locales: extensions.sqlite corrupt or missing
Profile0PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:363
Profile0PrefSources: prefs.js
Profile0Themes: extensions.sqlite corrupt or missing
Profiles:
 Profile1 (Default) - LastVersion=None/None (Out of date)
 Profile0 - LastVersion=94.0/20211028161635 (In use)
RunningIncompatibleAddons: False
SourcePackage: firefox
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/22/2021
dmi.bios.release: 5.17
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: P1.80
dmi.board.name: B550M/ac
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvrP1.80:bd04/22/2021:br5.17:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:skuToBeFilledByO.E.M.:rvnASRock:rnB550M/ac:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: To Be Filled By O.E.M.
dmi.product.sku: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.

[Olivier Tilloy (osomon)]

Thanks for the report Benjamin. Just so that I understand correctly, even after killing and restarting pulseaudio, the microphone won't register sound until the machine is rebooted?

[Benjamin Button (afeod)]

Hi Olivier,

Once the problem is triggered, it survives a reboot, and even switching operating systems (to Manjaro). I have to physically plug the microphone into a different USB port to fix it.