bin/58328: service mixerctl {stop,start} causes volume creep

[andrew.cagney%gmail.com@localhost]

>Number:         58328
>Category:       bin
>Synopsis:       service mixerctl {stop,start} causes volume creep
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 09 20:45:00 +0000 2024
>Originator:     cagney
>Release:        NetBSD thomasina 10.0_RC5 NetBSD 10.0_RC5
>Organization:
>Environment:
NetBSD thomasina 10.0_RC5 NetBSD 10.0_RC5 (GENERIC64) #0: Thu Mar  7 21:45:53 EST 2024  cagney@fedora:/home/cagney/netbsd-build/10/evbarm64/sys/arch/evbarm/compile/GENERIC64 evbarm

>Description:
audio 1 is a USB sound blaster:

[     6.187055] uaudio0 at uhub1 port 5 configuration 1 interface 0
[     6.187055] uaudio0: Creative Technology Ltd (0x041e) Sound BlasterX G1 (0x3249), rev 2.00/10.13, addr 5
[     6.217055] uaudio0: audio rev 1.00
[     6.217055] audio1 at uaudio0: playback, capture, full duplex, independent
[     6.227492] audio1: slinear_le:16 2ch 44100Hz, blk 10584 bytes (60ms) for playback
[     6.237622] audio1: slinear_le:16 2ch 44100Hz, blk 10800 bytes (61.2ms) for recording

 trying to get it to pre-set the audio. Notice how output.speaker is slowly increasing as the audio is saved/restored using service mixerctl.

first I save it, and change the value:

thomasina$ sudo service mixerctl stop
Saving mixer settings: mixer1.
thomasina$ mixerctl -d /dev/mixer1 -a
outputs.speaker.mute=off
outputs.speaker=232,232
record.mic.mute=off
record.mic=204,204
inputs.mic.mute=on
inputs.mic=214,214
thomasina$ mixerctl -d /dev/mixer1 -w outputs.speaker=200,200
outputs.speaker: 232,232 -> 203,203

but when it is restored it actually increases:

thomasina$ sudo service mixerctl start
Restoring mixer settings: mixer1.
thomasina$ mixerctl -d /dev/mixer1 -a
outputs.speaker.mute=off
outputs.speaker=238,238
record.mic.mute=off
record.mic=204,204
inputs.mic.mute=on
inputs.mic=214,214

same thing again, and it goes up another 10:

thomasina$ sudo service mixerctl stop
Saving mixer settings: mixer1.
thomasina$ sudo service mixerctl start
Restoring mixer settings: mixer1.
thomasina$ mixerctl -d /dev/mixer1 -a
outputs.speaker.mute=off
outputs.speaker=243,243
record.mic.mute=off
record.mic=204,204
inputs.mic.mute=on
inputs.mic=214,214

looking in the saved file the saved value is correct, but the restored value increases:

thomasina$ cat /var/db/mixer1.conf
outputs.speaker.mute=off
outputs.speaker=238,238
record.mic.mute=off
record.mic=204,204
inputs.mic.mute=on
inputs.mic=214,214


>How-To-Repeat:

>Fix: