buffer underruns with focusrite scarlett 2i2, even with tsched=0
Summary
I am getting buffer underflows when trying to output audio through my generation 2 scarlett 2i2 to my headphones.
environment
I'm running linux mint 19. The problem is however, not new, it was present even on a fresh install back in linuxmint 18.
Steps to reproduce
running aplay --file-type=raw --format=dat --duration=90 --verbose --dump-hw-params --device=default /dev/urandom
will consistently produce an underrun, as can be shown in output here:
What is the current bug behavior?
playing back audio through the scarlett 2i2 produces audible pauses in audio at a rate of approximately once a minute. The exact timing is not consistent. In addition, rtkit-daemon is spamming my syslog with thousands of messages about creating and dropping new threads for pulse audio's process. This is a small excerpt from my syslog so you can see what I mean.
This behavior occurs regardless of whether tsched=0 is set or not in default.pa
This buffer underflow notably does NOT occur if pulse audio is bypassed with pasuspender -- aplay --file-type=raw --channels=2 --format=S32_LE --rate=48000 --duration=90 --verbose --dump-hw-params --device=hw:USB,0 /dev/urandom
. This is an example.
What is the expected correct behavior?
buffer underflows should not occur on at least one scheduling setting, and pulse audio should ask rtkit for new processes at a reasonable rate.