[Tfug] USB bugaboo on Thinkpads

[Claude Rubinson]

On Tue, Jun 17, 2008 at 02:39:20PM -0700, John Karns wrote:
> On Fri, Jun 13, 2008 at 5:25 PM, Claude Rubinson <rubinson at u.arizona.edu> wrote:
> > On Fri, Jun 13, 2008 at 05:17:28PM -0700, John Karns wrote:
> >> What model?
> >
> > T40.
> >
> >> > ThinkPads also suffer.  It's not actually the USB ports but, rather,
> >> > something in the motherboard.  USB1 works but USB2 doesn't.  I tried
> >> > (and failed) to get IBM to replace the motherboard so my eventual
> >> > solution was to simply disable USB2, falling back to USB1.  Not a big
> >> > deal for me as I don't use USB peripherals much but maybe a deal
> >> > breaker for others.
> >>
> >> I haven't noticed a BIOS option on my machine to disable one or the other.
> >
> > Not in the bios but, rather, after boot via a `modprobe -r ehci_hcd`
> > in my /etc/rc.local.
> 
> But how does unloading the driver disable just one port, rather than both?

The problem isn't with the ports but, rather, the USB2 interface on
the motherboard.  Both ports work just fine.  But the motherboard
problem is such that nothing gets recognized when the USB2 module is
loaded.  (At least, that's my understanding).

Claude