Comment 55 for bug 1840725

A thing noticeable about the diff of the working and broken internal microphone is that the one that's not working shows the processes that are accessing the sound card (pacmd list-clients) includes libcanberra.

> application.name = "libcanberra"
> native-protocol.peer = "UNIX socket client"
> native-protocol.version = "32"
> application.version = "0.30"
> application.id = "org.freedesktop.libcanberra"
> application.process.id = "1550"
> application.process.user = "linda"
> application.process.host = "gazelle"
> application.process.binary = "gsd-media-keys"
> application.language = "en_US.UTF-8"
> window.x11.display = ":0"
> application.process.machine_id = "df4e0d95e2e6bc9d6b63c5a35372e1c3"
> application.process.session_id = "1"
> index: 2
> driver: <protocol-native.c>
> owner module: 12
> properties:

The other thing I wondered about is that in the broken one, the IRQ pin numbers reported by "cat /proc/asound/cards" and "lspci -vvv | grep -A9 Audio" are different.

cat /proc/asound/cards

 0 [HDMI ]: HDA-Intel - HDA Intel HDMI
                      HDA Intel HDMI at 0xf7e14000 irq 34
 1 [PCH ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xf7e10000 irq 33

lspci -vvv | grep -A9 Audio

00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06)
 Subsystem: CLEVO/KAPOK Computer Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 64 bytes
 Interrupt: pin A routed to IRQ 30
 Region 0: Memory at f7e14000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: <access denied>
 Kernel driver in use: snd_hda_intel
 Kernel modules: snd_hda_intel

--
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
 Subsystem: CLEVO/KAPOK Computer 8 Series/C220 Series Chipset High Definition Audio Controller
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 64 bytes
 Interrupt: pin A routed to IRQ 34
 Region 0: Memory at f7e10000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: <access denied>
 Kernel driver in use: snd_hda_intel
 Kernel modules: snd_hda_intel

I don't know if this has anything to do with why this internal mic stops working. I wonder what is calling libcanberra.