Driver not unset properly after kldunload

[Iasen Kostoff]

  Hi,
It seems that after I load and then unload a driver its name stays
linked to the device e.g:

nfe0 at pci0:10:0: class=0x068000 card=0x81411043 chip=0x005710de rev=0xa3
hdr=0x00

but of course if_nfe is neither compiled in kernel nor is loaded as
module anymore.
  I digged around in kernel and saw this in device_detach():

	if (!(dev->flags & DF_FIXEDCLASS))
		devclass_delete_device(dev->devclass, dev);

	dev->state = DS_NOTPRESENT;
	device_set_driver(dev, NULL);
	device_set_desc(dev, NULL);
	device_sysctl_fini(dev);

I've put some device_printf()s around and then looked at
devclass_delete_device(). It destroys (frees) a lot of the info about
the device and so the device_printf() prints device name as
"unknown" (NULL). That seems to be a problem for at least
device_set_driver(dev, NULL) - it doesn't unset the driver. I'm not so
sure about the other 2 but I guess it's same there. So when I changed the
order of this funcs everything worked fine (at least it looks like it
worked fine :) I'm not absolutely sure that this won't broke something
else). I've attached a patch for review.

(I've filled a PR http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/104777)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: subr_bus.c.diff
Type: text/x-patch
Size: 486 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-hackers/attachments/20061129/9b7a348e/subr_bus.c.bin