Hello,

I have been working with about twenty Scientific Linux machines for 
around five months, and in that time I have seen a complete USB failure 
on two different systems.  Some of our systems have USB mouses attached 
which generally work fine.  "Mouse not working" (the mouse 'freezes') is 
the fault reported by the users, but I think the problem is with all of 
the system USB capabilities.  Some of the details of the latest failure are:

In "/var/log/messages":
Feb 28 11:38:56 sysname kernel: drivers/usb/input/hid-core.c: not 
resubmitting, input0
Feb 28 11:38:57 sysname kernel: hub 1-0:1.0: connect-debounce failed, 
port 5 disabled
Feb 28 11:38:59 sysname kernel: hub 1-0:1.0: connect-debounce failed, 
port 6 disabled
Feb 28 11:38:59 sysname kernel: hub 2-0:1.0: port 2 disabled by hub 
(EMI?), re-enabling...
Feb 28 11:38:59 sysname kernel: usb 2-2: USB disconnect, address 2
Feb 28 11:39:01 sysname kernel: hub 1-0:1.0: connect-debounce failed, 
port 5 disabled
Feb 28 11:39:02 sysname kernel: hub 1-0:1.0: connect-debounce failed, 
port 6 disabled

(with the last two messages being repeated continuously.)

The last two messages also fill the system "dmesg" file.

The two systems that have experienced the failure have been running SL 
4.1 and SL 4.4 and have different hardware (a two year old Dell and a 5 
month old Viglen) so I think the chances of hardware incompatibility are 
minimal.  (Besides, there are plenty of similar systems here using USB 
without problems, and the two systems that have experienced failure are 
usually OK.)

I have used "system-config-mouse" to check that the system has 
recognised the mouse correctly.  It recognises a USB scroll mouse which 
is exactly what is in use.

A reboot fixes the problem, but without a mouse to close applications 
cleanly, data is lost.  Reboot to fix is not an ideal solution either!

I was wondering if anyone else had experienced similar, and more 
importantly if they found a cause and solution.  (I have seen in the 
list archive a similar problem reported, but the solution was to swap to 
a PS/2 mouse.  I do not have enough PS/2 mice to replace all of our USB 
mice, and this does not help a user wanting to use a USB stick drive etc.)

Any solution, or advice on where to look for more information that might 
point to a cause would be appreciated.

Thanks,
Jon

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Jon Clark
Scientific Officer
Dept. of Applied Mathematics
University of Sheffield
Sheffield, S3 7RH, UK
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