udev + usb2 kernel race?

Sitsofe Wheeler sitsofe at yahoo.com
Thu Feb 17 23:47:44 UTC 2005


We have a computer acting as a server that locks hard (PS2 keyboard
stops responding, prompt never returns, boot gets no further) when USB2
is enabled on FC3 (there were no lockups with FC1). I finally traced
this down to being some sort of interaction between udev and USB2. The
following steps reproduce the problem:

Boot the kernel with init=/bin/sh
mount -n -t proc /proc /proc
mount -n -t sysfs /sys /sys
/sbin/modprobe uhci-hcd

The machine will hang and not get any further nor will it respond to a
ctrl-alt-del or sysrq commands.

modprobing uhci-hcd before starting udev causes the problem to disappear
as does disabling USB2 (but leaving USB1 on) in the BIOS. Kernels tested
are kernel-2.6.9-1.667 and kernel-2.6.10-1.766_FC3. lspci prints the
following USB controller:
00:07.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1
Controller (rev 16)

Does this sound like a known issue?

Sitsofe | http://sucs.org/~sits/

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