Re: [PATCH v3 1/1] USB: core: let USB device know device node

Peter Chen
2016-01-25T09:31:15Z

On Mon, Jan 25, 2016 at 09:50:53AM +0100, Arnd Bergmann wrote:
> On Monday 25 January 2016 11:57:37 Peter Chen wrote:
> > >> >
> > >> > hub@3 { /* same external hub, highspeed mode */
> > >> > compatible = "usb2109,0812.591",
> > >> > "usb2109,0812",
> > >> > "usb2109,class9.0.1",
> > >> > "usb2109,class9.0",
> > >> > "usb2109,class9";
> > >> >
> > >> > #address-cells = <1>;
> > >> > #size-cells = <0>;
> > >> > reg = >;
> > >> >
> > >>
> > >> Why "reg" is 3 here?
> > >
> > > My mistake. It should be hub@1 and reg=<1>;
> > >
> > > I accidentally confused the port number and the device number.
> >
> > I think it should be hub@2 and reg=<0x2>.
> > According to Alan, we should use xHCI numbering scheme when
> > describing the ports of an xHCI root hub.
>
> For a single-port root hub, that would be right. My PC has
> two ports, so the first port has reg=<0x1> for SS and
> reg=<0x3> for HS.
>

Yes, you are right.

Alan, do you know which physical number is larger for
the same port, HS or SS port? Is it spec defined or vendor defined?
I haven't found related information at xHCI spec.

--

Best Regards,
Peter Chen