kern/56060: speaker(4) does not produce silence with 'P'

[rvp%SDF.ORG@localhost]

>Number:         56060
>Category:       kern
>Synopsis:       speaker(4) does not produce silence with 'P'
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 16 12:45:01 +0000 2021
>Originator:     RVP
>Release:        NetBSD-HEAD/amd64 9.99.81 (GENERIC) (build 202103152150Z)
>Organization:
>Environment:
NetBSD-HEAD/amd64 9.99.81 (GENERIC) (build 202103152150Z)
>Description:
The 'P' command to produce a pause/silence does not work because pitch is set to 20 Hz (for any pitch < 20 Hz).

# echo l32 cdef p1.... cdef > /dev/speaker

Here, the 'P' pause command produces a tone instead of a pause.
>How-To-Repeat:
See commands above.
>Fix:
audiobell() in dev/audio/audiobell.c should sleep for `period' ms (and
return) instead of setting pitch to 20 Hz if `pitch' is 0.