As reported, I couldn't mount a Cavalry external usb2 hard drive and following this got tons of dmesg lines of form:
hub 2-1:1.0: hub_port_status failed (err = -110)

From /var/log/messages, so every 5 seconds.
Apr 15 03:29:03 mu2 kernel: hub 2-1:1.0: hub_port_status failed (err = -110)
Apr 15 03:29:08 mu2 kernel: hub 2-1:1.0: hub_port_status failed (err = -110)
Apr 15 03:29:13 mu2 kernel: hub 2-1:1.0: hub_port_status failed (err = -110)

I got this to stop by unbinding and binding ehci_hcd device files as in this link
http://www.geekdevs.com/2010/04/solved-unable-to-enumerate-usb-device-disabling-ehci_hcd/


So, I did
cd /sys/bus/pci/drivers/ehci_hcd/
find ./ -name "0000:00:*" -print
./0000:00:1a.0
./0000:00:1d.0

sudo sh -c 'echo -n "0000:00:1a.0" > unbind'
and still got the dmesg messages, so did

sudo sh -c 'echo -n "0000:00:1d.0" > unbind'
which knocked out my usb2 mouse and keyboard #!@#

so, I had to remote log in and then rebind them
sudo sh -c 'echo -n "0000:00:1d.0" > bind'
which returned my mouse and keyboard, so feeling lucky I did
sudo sh -c 'echo -n "0000:00:1a.0" > bind'

and no more scummy messages of form
hub 2-1:1.0: hub_port_status failed (err = -110)


From what I read, usb2 don't always work supposedly with old stuff.   Didn't think my ext usb2 hd was THAT old.
Knocking out 1d.0 probably throws me to usb1 speeds.

 I'll see if this issue comes back.  If so, I'll try upgrading to SL6.2

Bill Lutter