Am 01.05.2015 um 08:36 schrieb Michael Biebl:
It's a workaround. So it might still be worth a bug report against the linux kernel.
I did that:Bug#783934: Acknowledgement (linux-image-3.16.0-4-amd64: systemd-udev-settle waiting 50 s during boot for snd-usb-audio)
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783934 Matthias