usb/176417: [xhci][cam][umass] kernelpanic while removing plugged in disk

[Wouter Oosterveld]

>Number:         176417
>Category:       usb
>Synopsis:       [xhci][cam][umass] kernelpanic while removing plugged in disk
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-usb
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Feb 25 11:20:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Wouter Oosterveld
>Release:        FreeBSD backup01-trimm.trimm.net 9.0-RELEASE-p3 FreeBSD 9.0-RELEASE-p3 #0: Tue Jun 12 02:52:29 UTC 2012     root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64
>Organization:
TriMM Multimedia
>Environment:
FreeBSD backup01-trimm.trimm.net 9.0-RELEASE-p3 FreeBSD 9.0-RELEASE-p3 #0: Tue Jun 12 02:52:29 UTC 2012     root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64
>Description:
Symptoms:

Messages of USB disk getting removed and rediscovered while still plugged in. 

Kernelpanic while 'removing' device.

Hardware:

Sweex 2 Port USB 3.0 Card PCI Express (cheap)
Chip reads D720200F1 / 1119KU603 / Japan

Western Digital "My Book Essential" with large >1TB disk.

Screenshot: https://www.dropbox.com/s/bol6fxl37e7mu3g/IMAG0478.jpg

Note:

Machine is a ZFS fileserver with 16TB raidz2 array.
>How-To-Repeat:
Plug in disk and see it getting 'removed' and rediscovered while being plugged in.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: