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

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

The following reply was made to PR kern/55130; it has been noted by GNATS.

From: Tetsuya Isaki <isaki%pastel-flower.jp@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost,
	gnats-admin%netbsd.org@localhost,
	netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/55130: audio sometimes plays a buzz sound for a few seconds when changing volume
Date: Sun, 12 Apr 2020 11:22:21 +0900

 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>