Chuck Ebbert wrote:
> In 2.6.21.1 when dock driver initialization fails it does a kfree()
> of dock_station. (Below, this is due to some error installing a
> notify handler.) Later when a bay is discovered it calls 
> is_dock_device() which attempts to lock the (nonexistent)
> dock_station. Reason is this test in is_dock_device():
> 
>         if (!dock_station)
>                 return 0;
> 
> dock_station is 0x6b6b6b6b after being freed. Either it needs
> to be zeroed or some other flag should be used to decide
> whether a dock station is present...
> 

Untested patch attached.