[HP Spectre x360 Convertible 15-df0xxx, Realtek ALC285, Black Mic, Left] Recording problem

[Carwyn Collinsworth]

Running Ubuntu 18.04.2 LTS. The built in microphone is not displayed and not available to select. The webcam, touchscreen, and speakers all work fine. Plugging in a headset with a microphone does allow audio to be heard through the external microphone.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.18.0-25.26~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-25-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: carwyn 2521 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Wed Jul 24 20:57:51 2019
InstallationDate: Installed on 2019-07-22 (3 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaRecordingTest: ALSA recording test through plughw:PCH failed
Symptom_Card: Built-in Audio - HDA Intel PCH
Symptom_Jack: Black Mic, Left
Symptom_Type: None of the above
Title: [HP Spectre x360 Convertible 15-df0xxx, Realtek ALC285, Black Mic, Left] Recording problem
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/22/2019
dmi.bios.vendor: AMI
dmi.bios.version: F.29
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 8518
dmi.board.vendor: HP
dmi.board.version: 10.47
dmi.chassis.type: 31
dmi.chassis.vendor: HP
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAMI:bvrF.29:bd04/22/2019:svnHP:pnHPSpectrex360Convertible15-df0xxx:pvr:rvnHP:rn8518:rvr10.47:cvnHP:ct31:cvrChassisVersion:
dmi.product.family: 103C_5335KV HP Spectre
dmi.product.name: HP Spectre x360 Convertible 15-df0xxx
dmi.product.sku: 6JY95UA#ABA
dmi.sys.vendor: HP

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jim (jimthree)]

Looks like the same issue I'm having on Thinkpad X1 Carbon 7th Gen running Ubuntu 19.04.

Debug output here:
http://alsa-project.org/db/?f=5c09dfb7b0fc0ff5ad32c0576893316f5613d3a1

As well as the Mic not being detected, and therefore not available for use in any applications, there is an issue with the master audio volume being either full-on or muted. individual mixer controls still work, but the main volume control does nothing other than mute the audio.