Disable xhci_hcd USB 3.0 module

[Greg KH]

On Mon, Dec 15, 2014 at 02:50:32PM -0200, Gustavo Duarte wrote:
> Hi Greg,
> 
> The Notebook has physically 2 port USB 2.0 and one port USB 3.0. The
> manufacturer specs says that and the output of the command lsusb says
> the same:
> 
> $ lsusb
> 
> Bus 001 Device 002: ID 058f:6254 Alcor Micro Corp. USB Hub
> Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
> Bus 001 Device 003: ID 5986:024b Acer, Inc

Note that USB 3 controllers control USB 2 hubs, odds are there is just
one controller chip in your laptop.

What does 'lspci' show?

> >What type of application isn't compatible with xhci-hcd?  Shouldn't we
> >fix something like this in the kernel as this isn't a good thing to
> >have.
> 
> The app, is a SDK of Robootic kits programming for kids.
> http://www.lejos.org/nxt/nxj/tutorial/Preliminaries/GettingStartedLinux.htm
> The bug is on the firmware-library of the SDK, so there isn't to fix
> on kernel/driver side.

I don't understand, what exact bug is there?

> I'm using the kernel compilde by ubuntu 12.04,
> 
> $ uname -r
> 3.8.0-33-generic

Wow that's old and obsolete, sorry, no one can help you with something
like that here :(

Also, _lots_ of USB 3 bugs have been fixed in the 2 years since that
kernel was released, please try updating and your issues should be
resolve.

> And i would like still using that, without recompile it, for this
> reason is my question, how can i disable xhci_hcd driver without
> recompile it. ?

You can unbind the driver from the device, but as I say above, I really
think this driver also controls the USB 2 hubs as well.  The output of
'lspci -k' will show this, can you provide the output of that?

thanks,

greg k-h