panic: resource_list_add: resource entry is busy

Hi,

I see the following panic:

panic: resource_list_add: resource entry is busy

When trying to kldload an older pccard driver. The call comes from the 
driver_added bus method somewhere down the tree. Loading the module 
before the kernel boots fixes the problem temporarily.

Any bells ringing or patch suggestions?

Seeing this on 9-stable, also believed that the same issue exists with 
10-current.

--HPS