[PATCH] for ng_ubt2 stalled transfers

[Maksim Yevmenkin]

Lars,

> Maksim has made a lot of changes to the Bluetooth driver. Maybe he can look
> into it?
>
> This looks like a NULL-pointer access to me.
>
> Maksim:
>
> In the ubt_detach routine, make sure that:
>
> 0) No further commands are accepted from the Netgraph stack.
> 1) You drain the task queue!
> 2) You drain all USB transfers: "usb2_transfer_drain()" called unlocked.
> 3) Set the "sc_node" to NULL.

please try attached patch for ng_ubt2 that hopefully addresses some of
the issues with stalled transfers. stalled transfers do not happen on
my machine, so i can not test it. i briefly kicked the tires and made
sure other things seems to work fine for me.

thanks,
max