Red Hat Bugzilla – Bug 29712
USB disconnect causes kernel hang
Last modified: 2007-04-18 12:31:47 EDT
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User-Agent: Mozilla/4.76 [en] (X11; U; Linux 2.2.16-3-usb i686)
I have a combination Video/USB switch attached to my machine. With the new
(2.2.17-14) kernel, a USB disconnect from the 4 port hub/switch hangs the
kernel. I ran, 'tail -f /var/log/messages' before I performed the
disconnect last time and no messages about the disconnect appeared, so I am
assuming that the hang happened on disconnect and not reconnect. (I
wouldn't know the difference otherwise as the disconnect also disconnects
Steps to Reproduce:
1. Boot 2.2.17-14 with a USB device attached.
2. Disconnect it.
Actual Results: Kernel hung. Even the second hand on the clock stopped.
Expected Results: Kernel should have kept running and on reconnect of the
USB hub should have noticed and reenabled the USB devices.
Have a 4 port USB hub/KVM switch attached with three devices - a keyboard,
a mouse, and a QuickCam.
I'm guessing the USB controller is OHCI since the bios can be set to make a
USB keyboard look like a PS/2 keyboard and the keyboard is usable from lilo
with or without this feature enabled.
Eek. Can you upgrade to 7.3?
That's my server machine, so I don't upgrade it quite as often as my laptop, but
it's been running 7.2 for some months and I haven't seen any more problems.
It's hardly scientific, as I haven't been using it from the console as much
recently, but it used to crash fairly often and the uptime's currently 40 days.
OK, 7.2 is good enough. It's only important to move off the 2.2
kernel, because it did not have right USB at all. We kinda sorta
made it working for most cases, but it was a kludge. For instance,
SMP was guaranteed to deadlock.
If the 7.2 keels over for you, open a new bug, I'll look.