HD audio problem on FreeBSD 12.1 bhyve VM

[Ali Abdallah]

Hello,

I'm running FreeBSD 12.1 release host with the HD bhyve audio patch
from 13-current.

On a OpenSUSE 15.2 bhyve guest, audio works perfectly fine. However, on
FreeBSD 12.1 only noise comes out. Using /dev/dsp4 (which is a USB sound
device), audio works fine, but not on /dev/dsp0, the default sound device
on my system.

I see the following relevant errors:

pcm0: chn_write(): pcm0:virtual:dsp0.vp0: play interrupt timeout,
channel dead
pcm0: chn_write(): pcm0:virtual:dsp0.vp0: play interrupt timeout,
channel dead

pin dump from FreeBSD 12.1 VM.
------------------------------
hdaa0: Dumping AFG pins:
hdaa0: nid   0x    as seq device       conn  jack    loc        color
misc
hdaa0:  3 00001010 1  0  Line-out      Jack  Unknown 0x00       Black
0
hdaa0:     Caps:    OUT              Sense: 0x80000000 (connected)
hdaa0:  5 00805020 2  0  Line-in       Jack  Unknown 0x00       Red
0
hdaa0:     Caps: IN                  Sense: 0x80000000 (connected)
hdaa0: NumGPIO=0 NumGPO=0 NumGPI=0 GPIWake=0 GPIUnsol=0

I tried sysctl dev.hdac.0.polling=1 with no success.

Note that: The above problem is also reproducible on 13-Current
20200917.

Any help is appreciated.

Kind regards,
Ali