Disable xhci_hcd USB 3.0 module

[Gustavo Duarte]

Greg,

Thanks for confirm my thought.

 I tried with a kernel 3.16 builded by Ubuntu guys,
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16-utopic/linux-image-3.16.0-031600-generic_3.16.0-031600.201408031935_amd64.deb


And the same behaviour, the Roboot lego kit can't establishes the
communication with the PC.

Do you think that with 3.18 kernel I will have a chance to resolve
this ? or there aren't significantly changes related tu USB between
3.16 and 3.18 version.


I guess that the problem is on SDK library usb communication, (libusb)
i'm going to make a research to this side.

Although this issue isn't resolved your help was very helpful, it was
like lightning.

Regards.
Gustavo .

On Mon, Dec 15, 2014 at 7:01 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Mon, Dec 15, 2014 at 06:47:21PM -0200, Gustavo Duarte wrote:
>> 00:14.0 USB controller: Intel Corporation ValleyView USB xHCI Host
>> Controller (rev 0e)
>>
>> Subsystem: CLEVO/KAPOK Computer Device 5471
>>
>> Kernel driver in use: xhci_hcd
>
> One host controller.
>
>> Seems like here is happening you are saying, one host-controller
>> (xHCI) manage the three USB port, right ?
>
> Yes.
>
>> May be i have a confusion, and i sorry for that, may be what i am
>> asking it is impossible or may be is a blunder, any way  following is
>> my thought:
>> "
>> I know that there are several PC, Notebooks with BIOS with the
>> capability to  enable/disable xHCI USB mode, where you can choice,
>> xHCI or EHCI.
>> For this reason i thought that could be possible, instead  by BIOS,
>> through some kernel configuration or passing a switch parameter at
>> boot time achieve the same behaviour.
>> "
>>
>> Do you are saying that, as this notebook has only one usb
>> host-controller, these option isn't possible ?
>
> Looks like it.  But I don't know what your bios looks like, poke around
> in there and see if you can find a setting like that.  I've never heard
> of such a thing though.  The xhci controller is a physical chip, it
> can't work like a ehci controller.
>
>> So the only remainder way to resolve this, is trying with a new one kernel ?
>
> To see if the bug you are having with a USB 3 device is fixed, yes.  You
> will not be able to ever get the ehci driver to work with this device no
> matter what kernel you change to, sorry.
>
> greg k-h