I have a Skylake system (ASRock Z170 Gaming-ITX/ac) with (x)Ubuntu 16.04.
My speakers are connected via the SPDIF port, but there is a problem.
When I inspect the audio profile (in pavucontrol), I see that Analog Stereo Output (unplugged) is selected.
The speakers play regularly, even if this profile is wrong, but the volume doesn't work correctly - anything above mute will cause the speakers to play at maximum volume.
If I choose the Digital Stereo (IEC958), the speakers won't receive any signal at all.
How can I fix this?
Debug info:
~$ grep "Codec:" /proc/asound/card*/codec*
/proc/asound/card0/codec#0:Codec: Realtek ALC1150
/proc/asound/card0/codec#2:Codec: Intel Skylake HDMI
~$ lspci -vv # extract
00:1f.3 Audio device: Intel Corporation Sunrise Point-H HD Audio (rev 31)
Subsystem: ASRock Incorporation Sunrise Point-H HD Audio
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: 32
Interrupt: pin A routed to IRQ 140
Region 0: Memory at df140000 (64-bit, non-prefetchable) [size=16K]
Region 4: Memory at df120000 (64-bit, non-prefetchable) [size=64K]
Capabilities: <access denied>
Kernel driver in use: snd_hda_intel
Kernel modules: snd_hda_intel
~$ dmesg | grep 00:1f.3
[ 0.181004] pci 0000:00:1f.3: [8086:a170] type 00 class 0x040300
[ 0.181034] pci 0000:00:1f.3: reg 0x10: [mem 0xdf140000-0xdf143fff 64bit]
[ 0.181062] pci 0000:00:1f.3: reg 0x20: [mem 0xdf120000-0xdf12ffff 64bit]
[ 0.181091] pci 0000:00:1f.3: PME# supported from D3hot D3cold
[ 0.181176] pci 0000:00:1f.3: System wakeup disabled by ACPI
[ 0.579846] iommu: Adding device 0000:00:1f.3 to group 8
[ 3.126041] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915_bpo])
[ 4.185983] input: HDA Intel PCH Front Mic as /devices/pci0000:00/0000:00:1f.3/sound/card0/input11
[ 4.186034] input: HDA Intel PCH Rear Mic as /devices/pci0000:00/0000:00:1f.3/sound/card0/input12
[ 4.186081] input: HDA Intel PCH Line as /devices/pci0000:00/0000:00:1f.3/sound/card0/input13
[ 4.186135] input: HDA Intel PCH Line Out as /devices/pci0000:00/0000:00:1f.3/sound/card0/input14
[ 4.186188] input: HDA Intel PCH Front Headphone as /devices/pci0000:00/0000:00:1f.3/sound/card0/input15
[ 4.186228] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1f.3/sound/card0/input16
[ 4.186267] input: HDA Intel PCH HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:1f.3/sound/card0/input17
[ 4.186304] input: HDA Intel PCH HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:1f.3/sound/card0/input18
