> My pci ep card did the same after its conversion. I still have no
> answers.

Just FYI.

My second ep card did not work after cfattach/cfdriver conversion
(machine locks up when "ifconfig ep1"), but it was not caused by 
changes to the driver. It was caused by changes to the order of 
probing devices. i.e. ed driver probing routine makes ep card 
strange state. (before changes, probing is done in "ed" -> "ep"
order, after changes, probing is done in "ep" -> "ed" order.)
ed card is not exist in my system, but kernel config file included
ed device on same I/O address as my first ep card, though trouble 
was happened on second ep card.
It was fixed by removing ed device from my kernel config file.

But mine is ISA ep card, so that this may not concern with your trouble.
--
soda@sra.co.jp		Software Research Associates, Inc., Japan
(Noriyuki Soda)		   software tools and technology group