THank you for your help.   This is the result:

mount -t usbdevfs none /proc/bus/usb
mount: mount point /proc/bus/usb does not exist

mkdir /proc/bus/usb
mkdir: cannot create directory `/proc/bus/usb': No such file or directory

And supposed I tried a directory that exist:

mount -t usbdevfs none /proc/bus
mount: unknown filesystem type 'usbdevfs'

The exact mirror (before the problem start I mirrored the system) is still
working today, and I have not find any difference between the two version
so far.

On Mon, Oct 1, 2012 at 12:51 PM, [off-list ref] wrote:

This steps helped me when I had same problem in SUSE9.

The Reason is "/proc/bus/usb/ doesn't has any entry where actually lsusb
searches to show USB BUS devices.To make that happen you have to manually .
Mount the Bus devices using below command.

mount -t usbdevfs none /proc/bus/usb/

And you are done.
Now lsusb should show all USB BUS devies.

Thanks
Ashish Bunkar

-----Original Message-----
From: kernelnewbies-bounces at kernelnewbies.org [mailto:
kernelnewbies-bounces at kernelnewbies.org] On Behalf Of Peter Teoh
Sent: Saturday, September 29, 2012 7:12 AM
To: kernelnewbies at kernelnewbies.org
Subject: Why "lsusb" return nothing?

I entered "lsusb" at the command line (as root) and nothing is return, not
even any error message.

Doing a strace the last few lines are:

open("/dev/bus/usb", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1
ENOENT (No such file or directory) open("/proc/bus/usb",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or
directory)

What happened?

This is Ubuntu 10.04 (it used NOT to be like that, not sure I what did
wrong last time).   But running a VirtualBox INSIDE this same OS, I
was able to get result from "lsusb" (after enabling the USB devices in
VirtualBox interface) and strace gives result:

open("/dev/bus/usb/001/002", O_RDWR)    = 3
ioctl(3, USBDEVFS_IOCTL, 0xbff6f75c)    = -1 ENOTTY (Inappropriate
ioctl for device)
close(3)                                = 0
open("/dev/bus/usb/001/001", O_RDWR)    = 3

Why the difference?

--
Regards,
Peter Teoh

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-- 
Regards,
Peter Teoh
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