pcm1:virtual:dsp1.vp0: play interrupt timeout, channel dead

FreeBSD BSD_12 12.0-CURRENT FreeBSD 12.0-CURRENT #12 r331138: Sun Mar 18 
15:09:37 EDT 2018 
root_at_BSD_12:/usr/obj/usr/src/amd64.amd64/sys/MYKERNEL  amd64

I recently started to see strange behavior on 2 different machines and was 
wondering if anyone else has run into it.  Within the last few days, I 
have been experiencing a reproduceable problem with sound.  It happens in 
VLC and also in Virtualbox watching video in a browser.

I get the following log entry:

Mar 18 18:10:26 BSD_12 kernel: pcm1: chn_write(): pcm1:virtual:dsp1.vp0: 
play interrupt timeout, channel dead

and then sound is dead in all applications.  Any ideas what to do?

I tried the following:

rebuilt world and kernel several times
rebuilt libvorbis
rebuilt ffmpeg
rebuilt vlc
rebuilt Vbox and kmod

The only thing I can think of as a possible issue is an update to 
libvorbis recently, cc'ing ports just in case.

Is there a way to restart the audio subsystem without rebooting the 
machine?  Is there anymore info I can provide to troubleshoot?

# dmesg | grep pcm
pcm0: <ATI R6xx (HDMI)> at nid 3 on hdaa0
pcm1: <Realtek ALC892 (Rear Analog 7.1/2.0)> at nid 20,22,21,23 and 24,26 
on hdaa1
pcm2: <Realtek ALC892 (Front Analog)> at nid 27 and 25 on hdaa1
pcm1: chn_write(): pcm1:virtual:dsp1.vp0: play interrupt timeout, channel 
dead


# pciconf -lv
hostb0_at_pci0:0:0:0:	class=0x060000 card=0x7a341462 chip=0x14501022 
rev=0x00 hdr=0x00
     vendor     = 'Advanced Micro Devices, Inc. [AMD]'
     device     = 'Family 17h (Models 00h-0fh) Root Complex'
     class      = bridge
     subclass   = HOST-PCI

hdac0_at_pci0:34:0:1:	class=0x040300 card=0xaa681545 chip=0xaa681002 
rev=0x00 hdr=0x00
     vendor     = 'Advanced Micro Devices, Inc. [AMD/ATI]'
     device     = 'Cedar HDMI Audio [Radeon HD 5400/6300/7300 Series]'
     class      = multimedia
     subclass   = HDA


hdac1_at_pci0:36:0:3:	class=0x040300 card=0xda341462 chip=0x14571022 
rev=0x00 hdr=0x00
     vendor     = 'Advanced Micro Devices, Inc. [AMD]'
     device     = 'Family 17h (Models 00h-0fh) HD Audio Controller'
     class      = multimedia
     subclass   = HDA


Thanks in advance for any advice.