[2.5.15-rc2] khubd eating all CPU upon trying to remove pwc driver

[Shawn Starr <shawn.starr@rogers.com>]

Hi Greg, 

It appears while debugging camserv to add some features, if I kill camserv 
prematurely, and try to unload the pwc driver I am unable to. 

I get the following:

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
1068 root      20  -5     0    0    0 R 95.8  0.0   3:26.84 khubd

The kernel USB hub daemon goes nuts. 

If I disconnect the cam from the USB

[4294920.159000] pwc pwc_isoc_handler() called with status -84 [CRC/Timeout 
(could be anything)].
[4294920.166000] hub 2-0:1.0: state 5 ports 2 chg 0000 evt 0004
[4294920.166000] uhci_hcd 0000:00:1d.1: port 2 portsc 008a,00
[4294920.166000] hub 2-0:1.0: port 2, status 0100, change 0003, 12 Mb/s
[4294920.166000] usb 2-2: USB disconnect, address 4
[4294920.166000] usb 2-2: usb_disable_device nuking all URBs
[4294920.166000] uhci_hcd 0000:00:1d.1: shutdown urb f56a10fc pipe 00028480 
ep5in-iso
[4294920.166000] uhci_hcd 0000:00:1d.1: shutdown urb f5680d04 pipe 00028480 
ep5in-iso
[4294920.167000] pwc pwc_isoc_handler() called with status -108 [Unknown].
[4294920.167000] pwc Error (-19) re-submitting urb in pwc_isoc_handler.
[4294920.167000] pwc pwc_isoc_handler() called with status -108 [Unknown].
[4294920.167000] pwc Error (-19) re-submitting urb in pwc_isoc_handler.
[4294920.167000] usb 2-2: unregistering interface 2-2:1.0
[4294920.167000] pwc Disconnected while webcam is in use!
[4294921.416000] uhci_hcd 0000:00:1d.1: suspend_rh (auto-stop)

What information do you need? Yes I know it's bad to yank out USB devices that 
aren't properly shut down.

Thanks, 

Shawn.