Arch Linux

Description:

Recent update of nvidia and linux breaks the sound output on DisplayPort.

Steps to reproduce:
1. Make sure that DisplayPort v1.2 is disabled in the output device.
2. Check the sound - should work correctly.
3. Upgrade to nvidia 384.59 & linux 4.12.3
4. Reboot

Actual result:
No sound on DP output (however the video output is visible).

- In pavucontrol all profiles in the "GK106 HDMI Audio controller" are unplugged and unavailable. `pacmd list cards` shows correct amount of ports on graphic card, however all of them are unavailable. There is no way to turn them on.
- `aplay` with the correct device does not show any errors, but still there is no sound.
- snd_hda_codec_hdmi is present in the `lsmod` output
- journal and dmesg does not contain any error messages
- VT switching [1] does not help.

Expected result:
DP sound output works (at least one port in `pacmd list cards` is available and enabled).

Workaround:
Downgrade to nvidia 381.22-4 and linux 4.11.9-1 and reboot.

lspci:

01:00.0 VGA compatible controller: NVIDIA Corporation GK106GLM [Quadro K2100M] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GK106 HDMI Audio Controller (rev a1)


1. https://wiki.archlinux.org/index.php/PulseAudio/Troubleshooting#No_HDMI_sound_output_after_some_time_with_the_monitor_turned_off