Pops in audio with Kernel 4.19.118-v7+ #1311 and Roon Bridge

[dsnyder0pc]

Describe the bug
I'm running the Roon Bridge application (build 171) on DietPi. A freshly flashed DietPi image "ships" with kernel 4.19.118, and when using that kernel, I'm hearing pops and ticks in audio playback. However, when I switch to a different microSD card that was updated to DietPi 6.30.0 but still has kernel 4.19.97 (did not do apt full-grade, everything sounds fine.

To reproduce
Flash a microSD card with the latest DietPi image. Install Roon Bridge. Connect a USB DAC to the RPi and play any music.

Expected behaviour
Assuming a reasonably good DAC, music should sound nice.

Actual behaviour
Pops and ticks in the audio. You can hear what I'm hearing by playing this file: https://www.dsnyder.ws-e.com/ts/linux_4.19.97_vs_4.19.118.mp3

System

• Which model of Raspberry Pi? RPi CM 3+ (armv7l)
• Which OS and version? Raspberry Pi reference 2020-05-27
• Which firmware version:

Apr 15 2020 11:43:28
Copyright (c) 2012 Broadcom
version 82f9bb929ce2186eb1824178c1ae82902ad6275c (clean) (release) (start_cd)

• Which kernel version? Linux usbridge 4.19.118-v7+ Rpi4 eth_led0 set to 4, amber light stays on #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux

Logs
Again, please listen to this file to hear what I'm hearing: https://www.dsnyder.ws-e.com/ts/linux_4.19.97_vs_4.19.118.mp3

Additional context

• I can only reproduce this problem while streaming the file from Roon and with kernel 4.19.118. When I play the file locally (eg., download it from here to the local microSD card and use the SoX play command), it sounds fine with both kernels.
• Others in the Roon community can reproduce this problem and say the workaround is to go back to the kernel that came with the January 26th DietPi image.
• More context in RPi | Pops in audio with Kernel 4.19.118-v7+ #1311 and Roon Bridge MichaIng/DietPi#3608

[dsnyder0pc]

I've created a workaround that rolls back to the last good kernel. Works for me, but no guarantee that it will work for everyone. :)

# curl -L ws-e.com/to-97.sh | bash

https://github.com/dsnyder0pc/DietPi/blob/master/to-97.sh

[MichaIng]

Little note about the workaround, before running the curl command:

• Works OOTB on RPi2 and RPi3(+) only.
• On other RPi models, adjust the line target="4.19.97-v7+":
  • RPi1/Zero: target="4.19.97+"
  • RPi4: target="4.19.97-v7l+"
  • With 64-bit kernel enabled: target="4.19.97-v8+"

Hopefully the kernel version gives a hint which commit is the culprit.