how to activate usb port

[abdelkader belahcene <abelahcene@gmail.com>]

Hi,
Sometimes (Not Always)  , the usb port are not activate, lsusb gives
$lsusb
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

while usb pen (flash disk) and webcam are both connected !!!

I tryed other usb  port, plug in and out, nothing is changed !!!?

the light of usb pen  is off, no lights, while normally it is on.

How to activate the ports?  is it necessary to reload modules , if so which one?

thanks for help