Comment 23 for bug 159189

The usbfs mount point /proc/bus/usb is deprecated.
The -t option of lsusb (from sys-apps/usbutils package) relies on /proc/bus/usb/devices.

Ubuntu guys have developed a patch to make -t work even without usbfs.
The patch is pretty new, and has been just released:
https://bugs.launchpad.net/ubuntu/+source/usbutils/+bug/159189

Maybe Gentoo people could benefit from such patch, so I'm opening this bug here (and also because if more people revise/test such patch, better for everyone). Of course, the best thing is to have such patch approved and applied upstream.