[ltp] usb 2.0 operating as usb 1.1

Christian Hauser linux-thinkpad@linux-thinkpad.org
Sun, 19 Jun 2005 18:51:57 +0200

Matthias Himber wrote:
> Short answer: your southbridge is about to die, get your system board 
> replaced. Hopefully its still under warranty.
> Long answer: a number of Intel chipsets for Pentium IV and Pentium M 
> processors have a design flaw that makes the southbridge (which contains the 
> USB host controllers) especially sensitive to static electricity. As a result 
> there is a (small) risk that when plugging in or removing a USB device causes 
> damage to the chip. Usually, the first symptom is broken USB 2.0, behaving in 
> exactly the way you described (ie, works under Windows, but only after some 
> waiting and as if it was connected to a USB 1.1 controller, not a USB 2.0 
> one, and not at all under Linux unless you unload the USB 2.0 driver). This 
> tends to lead to a completely dead chipset a short time later, so better get 
> it serviced NOW.
> Incidentially, exactly this happened to me around last Christmas. Same 
> Thinkpad model, too.

Thanks a lot Matthias, I have the same problem, but ignored it so far, 
because I hardly ever use USB devices. But not that I know I'll get this 
fixed before my warranty ends.