DisplayPort/HDMI audio getting stuck

polmolompa commented 1 year ago

Qubes OS release

Qubes 4.1 It was working fine in Qubes 4.0, so something in 4.1 introduced this.

Brief summary

Sound output via DisplayPort gets stuck after a few hundred ms.

Steps to reproduce

In dom0:

Open pavucontrol and turn off all sound cards under configuration.
Play sound directly using aplay on the different sound cards and outputs.

(The issue also exists when playing audio in other ways, such as PulseAudio, this is just the lowest level way I found for reproducing the issue.)

Expected behavior

Sound plays correctly on all outputs without stopping.

Actual behavior

When trying to play sound through the DisplayPort/HDMI output, the output stops after a few hundred milliseconds and aplay hangs indefinitely. No related error messages appear in dmesg or journalctl. Other outputs, such as internal speakers, work fine.

Additional information

This happens on a ThinkPad T440p. with an i5-4330M CPU.
The issue persists with different DisplayPort cables and monitors.
Issue already persists since installing Qubes 4.1 in early 2022.
Reinstalling Qubes did not help.

polmolompa commented 1 year ago

# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 0: ALC3232 Analog [ALC3232 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

# aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
hdmi:CARD=HDMI,DEV=0
    HDA Intel HDMI, HDMI 0
    HDMI Audio Output
hdmi:CARD=HDMI,DEV=1
    HDA Intel HDMI, HDMI 1
    HDMI Audio Output
hdmi:CARD=HDMI,DEV=2
    HDA Intel HDMI, HDMI 2
    HDMI Audio Output
default:CARD=PCH
    HDA Intel PCH, ALC3232 Analog
    Default Audio Device
sysdefault:CARD=PCH
    HDA Intel PCH, ALC3232 Analog
    Default Audio Device
front:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    Front output / input
surround21:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
    HDA Intel PCH, ALC3232 Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

aplay -D hw:0,8 -c2 piano2.wav
Playing WAVE 'piano2.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[Hangs indefinitely]

(The wav file works on another computer. Also tested several other wav files, as well as hw:0,3 and hw:0,7, all produce the same result.)

polmolompa commented 8 months ago

The issue persists on a fresh install of Qubes 4.2. Although there are some minor differences:

play -l now labels the output (0,3) with the monitor model.
When trying to play audio via pulse audio the part of the GUI that shows the current volume of what's playing no longer gets stuck after a short time, but instead continuously shows the, presumably correct, volume.

QubesOS / qubes-issues