0226a0496e
already powered down. This change prevents PCI bus exceptions
(indicated by NMI) when, for example, I detach the whole device
tree on a Soekris net4521:
com1: detached
NMI ... going to debugger
Stopped in pid 0.1 (system) at netbsd:sipcom_stop+0x4d: pushl $0
db{0}> continue
NMI ... going to debugger
Stopped in pid 0.1 (system) at netbsd:sipcom_stop+0x149: addl $0x10,%e
sp
db{0}> continue
sip0: detached
(On the AMD Elan SC520, the NMI occurs at the instruction after
the write or, if the write was posted, at either that instruction
or some later one.)