USB sound card causes system lockup

[Kevin Wortman]

Hi,

I am trying to get a Creative Sound Blaster MP3+ USB sound card to
work under 5.2.1. I added snd_uaudio_load="YES" to /boot/loader.conf,
and dmesg shows the device being found:

uaudio_add_selector: NOT IMPLEMENTED
uaudio0: audio rev 1.00
pcm0: <USB Audio> on uaudio0

There are /dev/dsp* and /dev/mixer entries, and usbdevs shows

addr 1: OHCI root hub, SiS
 addr 2: USB Audio, Creative
addr 1: OHCI root hub, SiS
addr 1: OHCI root hub, SiS
 addr 2: ORTEK USB Combo Keyboard, ORTEK

However any time I interact with the sound card, for example starting
esd or altering the volume with the GNOME volume slider, the system
locks up hard.  Will not respond to CTRL-ALT-Backspace or -Delete.

Any suggestions?

Thanks,
Kevin Wortman