kern/54700: beeps through audio device stop happening

[dholland%netbsd.org@localhost]

>Number:         54700
>Category:       kern
>Synopsis:       beeps through audio device stop happening
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 16 11:55:00 +0000 2019
>Originator:     David A. Holland
>Release:        NetBSD 8.99.41 (20190528)
>Organization:
>Environment:
System: NetBSD macaran 8.99.41 NetBSD 8.99.41 (MACARAN) #54: Tue May 28 18:10:5\
6 EDT 2019 dholland@macaran:/usr/src/sys/arch/amd64/compile/MACARAN amd64
Architecture: x86_64
Machine: amd64
>Description:

As noted in passing in 54243, after sufficient (considerable) uptime,
beeps through the audio system stop sounding. Beeps through the PC
speaker continue to work. Other uses of the audio system (mpg123, mpv,
etc) continue to work.

There is no obvious trigger and it's not clear that it always happens
or happens at any given uptime, though I've observed it on more than
one machine now, all with kernels from earlyish in 2018. Might be
fixed at this point; we'll see eventually if it continues to happen.

It is also not absolutely certain if these beeps cut out permanently
until reboot or come back after a while -- it is not clear that I'd
notice if they came back on their own while I'd been away from the
computer.

>How-To-Repeat:

Beep. Wait. Maybe.

>Fix:

No idea.