kern/54187: dev/audio/t_pad:pad_output test now fails

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         54187
>Category:       kern
>Synopsis:       dev/audio/t_pad:pad_output test now fails
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 10 07:05:00 +0000 2019
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:

>Environment:
System: NetBSD
Architecture: i386
Machine: i386
>Description:

The pad_output test case of the dev/audio/t_pad test program is now
failing on the i386 testbed, and also on real amd64 hardware:

  http://releng.netbsd.org/b5reports/i386/2019/2019.05.09.07.38.44/test.html#dev_audio_t_pad_pad_output
  http://www.gson.org/netbsd/bugs/build/amd64-baremetal/2019/2019.05.09.13.07.35/test.html#dev_audio_t_pad_pad_output

This did not result in an automated report by the i386 testbed because
the test case had not been consistently passing before it started
consistently failing:

  2019.05.07.22.00.10/test.log.gz:    pad_output: [9.498967s] Passed.
  2019.05.08.01.08.18/test.log.gz:    pad_output: [6.051286s] Passed.
  2019.05.08.04.34.33/test.log.gz:    pad_output: [5.887895s] Passed.
  2019.05.08.06.57.18/test.log.gz:    pad_output: [3.892165s] Failed: atf-check failed; see the output of the test for details
  2019.05.08.07.44.28/test.log.gz:    pad_output: [5.342946s] Passed.
  2019.05.08.09.53.43/test.log.gz:    pad_output: [5.826627s] Passed.
  2019.05.08.14.25.39/test.log.gz:    pad_output: [4.001009s] Failed: atf-check failed; see the output of the test for details
  2019.05.08.18.00.16/test.log.gz:    pad_output: [4.115639s] Failed: atf-check failed; see the output of the test for details
  2019.05.08.19.34.09/test.log.gz:    pad_output: [4.522798s] Failed: atf-check failed; see the output of the test for details
  2019.05.08.22.01.47/test.log.gz:    pad_output: [6.781709s] Failed: atf-check failed; see the output of the test for details
  2019.05.09.02.43.35/test.log.gz:    pad_output: [4.429132s] Failed: atf-check failed; see the output of the test for details

>How-To-Repeat:

Run the ATF tests.

>Fix: