kern/44362: USB port n reset failed

[rnestor%mac.com@localhost]

>Number:         44362
>Category:       kern
>Synopsis:       USB port n reset failed
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 09 17:35:00 +0000 2011
>Originator:     Bob Nestor
>Release:        NetBSD 5.1 (GENERIC) amd64
>Organization:
>Environment:
NetBSD bandit.home.net 5.1 NetBSD 5.1 (GENERIC) #0: Sat Nov  6 13:19:33 UTC 
2010  
builds%b6.netbsd.org@localhost:/home/builds/ab/netbsd-5-1-RELEASE/amd64/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/amd64/compile/GENERIC
 amd64
>Description:
My monitor, keyboard and mouse are connected thru an IOgear GCS634U KVM switch. 
 The keyboard and mouse are USB devices.  When the KVM switch is commanded to 
switch devices to a different computer, NetBSD detects the USB disconnects and 
logs the events.  When switched back to the NetBSD system the USB sub-system 
usually detects the connects, logs the events and reconnects the devices.  
Occasionally during a reconnect sequence the USB sub-system reports "port ? 
reset failed" where "?" is the port for the mouse.  At this point the mouse is 
unusable.  The only way to recover the NetBSD system at this point is to reboot.

The problem doesn't happen all the time, only about once in about 50 
disconnect/reconnect cycles.  Moving the USB connections to a different port on 
the IOgear box doesn't help.  The ports on the IOgear box are known to be 
operational as they work with other non-NetBSD systems.
>How-To-Repeat:
See descripion.
>Fix:
Unknown