root@OpenWrt:~# opkg install kmod-usb2
Installing kmod-usb2 (2.6.39.4-1) to root...
Downloading http://downloads.openwrt.org/snapshots/trunk/ramips/packages/kmod-usb2_2.6.39.4-1_ramips.ipk.
Multiple packages (kernel and kernel) providing same name marked HOLD or PREFER. Using latest.
Multiple packages (kernel and kernel) providing same name marked HOLD or PREFER. Using latest.
Not downgrading package kernel on root from 2.6.39.4-1-45d42be19c31ef550376f28186aaab97 to 2.6.39.4-1-8ed5f069113be63865a072d80bbf746f.
Collected errors:
 * opkg_install_cmd: Cannot install package kmod-usb2.
root@OpenWrt:~#