45 second autoconfig delay

[Edgar Fuß]

With a -10 kernel, I experience a >45s delay during boot at
[   4.7185738] wsmouse0 at ums0 mux 0
[  51.1886454] ipmi0: version 32.0 interface KCS iobase 0xca8/0x8 spacing 4
How can I track down what causes this delay?