Re: kern/55130: audio sometimes plays a buzz sound for a few seconds when changing volume

[Tetsuya Isaki <isaki%pastel-flower.jp@localhost>]

At Sat,  4 Apr 2020 18:15:02 +0000 (UTC),
coypu%sdf.org@localhost wrote:
>  I have bindings that do this:
>  
>  #!/bin/sh
>  mixerctl -w outputs.master-=3
>  mixerctl -w outputs.master2-=3
>  
>  I often run this script, and a similar one for raising volume.

I was not able to reproduce it on my environment.
I played mp3 forever by

 # sysctl -w hw.audio0.blk_ms=1
 % mpv -loop 0 some.mp3

and executed this script, for over 12 hours total.
 -----
 #!/bin/sh
 while true; do
 mixerctl -w outputs.master+=3
 mixerctl -w outputs.master2+=3
 sleep 1
 mixerctl -w outputs.master-=3
 mixerctl -w outputs.master2-=3
 sleep 1
 done
 -----
 (Here my volume delta=3)

The machine I tried is:
cpu0 at mainbus0 apid 0
cpu0: Intel(R) Core(TM) i7 CPU       L 620  @ 2.00GHz, id 0x20652
cpu0: node 0, package 0, core 0, smt 0
cpu1 at mainbus0 apid 1
cpu1: Intel(R) Core(TM) i7 CPU       L 620  @ 2.00GHz, id 0x20652
cpu1: node 0, package 0, core 0, smt 1
cpu2 at mainbus0 apid 4
cpu2: Intel(R) Core(TM) i7 CPU       L 620  @ 2.00GHz, id 0x20652
cpu2: node 0, package 0, core 2, smt 0
cpu3 at mainbus0 apid 5
cpu3: Intel(R) Core(TM) i7 CPU       L 620  @ 2.00GHz, id 0x20652
cpu3: node 0, package 0, core 2, smt 1
:
hdaudio0 at pci0 dev 27 function 0: HD Audio Controller
hdaudio0: interrupting at msi1 vec 0
hdaudio0: HDA ver. 1.0, OSS 4, ISS 4, BSS 0, SDO 1, 64-bit
hdafg0 at hdaudio0: vendor 14f1 product 5069
hdafg0: DAC00 2ch: HP Out [Jack]
hdafg0: ADC01 2ch: Mic In [Jack]
hdafg0: DAC02 2ch: Speaker [Built-In]
hdafg0: ADC03 2ch: Mic In [Built-In]
hdafg0: 2ch/2ch 44100Hz 48000Hz 96000Hz PCM16 PCM20 PCM24 AC3
audio0 at hdafg0: playback, capture, full duplex, independent
audio0: slinear_le:16 2ch 48000Hz, blk 10ms for playback
audio0: slinear_le:16 2ch 48000Hz, blk 10ms for recording

# uname -srm
NetBSD 9.99.46 amd64

>  It seems to happen more after the audio latency was changed blk_ms -> 4

Is there any difference in the rate that problem occurs
between blk_ms=1 and blk_ms=40 ?


I'm not sure but anyway, I guess it's almost problem on some
particular models of hdafg(4) because:
- It's unlikely that audio layer causes such problem.
  Changing volume mixer variable is almost passed to MD driver
  as is.  Audio layer almost does nothing for it.
- I've never had such problem with either my hdafg(4) or other
  drivers.
- I've heard about noise problem on another hdafg(4) model in
  the same vendor id with yours, via private email.

I hope hdafg person take look this.
Thanks,
---
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>