Comment 2 for bug 1458136

post pulseaudio verbose log

https://wiki.ubuntu.com/PulseAudio/Log

are there any error message in pulseaudio verbose log

when the stream tag of analog convertor and digital convertor are same vlaue 8

this imply driver output signal to both analog and digital

the driver should return EBUSY error when pulseaudio open digital device

you have to turn off "IEC958 Default PCM"

Simple mixer control 'IEC958 Default PCM',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]

Node 0x02 [Audio Output] wcaps 0x41d: Stereo Amp-Out
  Control: name="Front Playback Volume", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Device: name="ALC892 Analog", type="Audio", device=0
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x3f 0x3f]
  Converter: stream=8, channel=0
  PCM:
    rates [0x560]: 44100 48000 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0
Node 0x03 [Audio Output] wcaps 0x41d: Stereo Amp-Out
  Control: name="Surround Playback Volume", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x3f 0x3f]
  Converter: stream=8, channel=0
  PCM:
    rates [0x560]: 44100 48000 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0
Node 0x04 [Audio Output] wcaps 0x41d: Stereo Amp-Out
  Control: name="Center Playback Volume", index=0, device=0
    ControlAmp: chs=1, dir=Out, idx=0, ofs=0
  Control: name="LFE Playback Volume", index=0, device=0
    ControlAmp: chs=2, dir=Out, idx=0, ofs=0
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x3f 0x3f]
  Converter: stream=8, channel=0
  PCM:
    rates [0x560]: 44100 48000 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0
Node 0x05 [Audio Output] wcaps 0x41d: Stereo Amp-Out
  Control: name="Side Playback Volume", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x3f 0x3f]
  Converter: stream=8, channel=0
  PCM:
    rates [0x560]: 44100 48000 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0
Node 0x06 [Audio Output] wcaps 0x611: Stereo Digital
  Control: name="IEC958 Playback Con Mask", index=0, device=0
  Control: name="IEC958 Playback Pro Mask", index=0, device=0
  Control: name="IEC958 Playback Default", index=0, device=0
  Control: name="IEC958 Playback Switch", index=0, device=0
  Control: name="IEC958 Default PCM Playback Switch", index=0, device=0
  Device: name="ALC892 Digital", type="SPDIF", device=1
  Converter: stream=8, channel=0
  Digital: Enabled
  Digital category: 0x0
  IEC Coding Type: 0x0
  PCM:
    rates [0x5f0]: 32000 44100 48000 88200 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0