RPi 4 prints errors from pa_devs for Behringer UMC404 HD

[philburk]

Describe the bug

When running bin/pa_devs on a Raspberry Pi 4 with a 32-bit OS
connected to a Behringer UMC404HD USB audio interface,
I get errors when printing sample rates.

To Reproduce
Steps to reproduce the behavior. Include code if applicable.

1. Install a 32-bit Debian OS using the Pi Imager.
2. Download PortAudio from GitHub.
3. sudo apt-get install libasound2-dev
4. cd portaudio
5. ./configure && make
6. Connect a UMC404HD
7. bin/pa_devs

Expected behavior
Print available devices with no errors.

Actual behavior

For the HDMI device I get:

Supported standard sample rates
for half-duplex 16 bit 2 channel output =
Expression 'hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, parameters->sampleFormat )' failed in 'src/
hostapi/alsa/pa_linux_alsa.c', line: 1834

For the Behringer UMC404HD I get:

Expression 'ret' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1873
Expression 'ret' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1873

Full dump: pa_devs_output.txt

Desktop OS:

Linux rpi4-32-01 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux

[philburk]

I think this is NOT a regression.

I downloaded the pa_stable_v190700_20210406.tgz from https://files.portaudio.com/download.html
and built the code using configure.

I get the same error but with a different line number, L1818.

[philburk]

The error messages is from this line:
https://github.com/PortAudio/portaudio/blame/5d01510dc907c1791a4945c9bc4dd6d403c9a410/src/hostapi/alsa/pa_linux_alsa.c#L1873

I printed ret and it was -6.

Gemini says "In the ALSA library, a return value of -6 corresponds to the standard Linux error code -ENXIO (No such device or address)".

aplay -l says:

**** List of PLAYBACK Hardware Devices ****
card 0: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 3: U192k [UMC404HD 192k], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

[philburk]

I tried:

systemctl --user stop pulseaudio.socket pulseaudio.service
systemctl --user stop pipewire.socket pipewire.service

That did not help.