[PATCH 2/2] dt-bindings: usb: snps,dwc3: Fix downstream port numbering

[Konrad Dybcio]

On 10/14/26 11:44 AM, Neil Armstrong wrote:
> On 10/14/26 11:29, Chen-Yu Tsai wrote:
>> On Wed, Oct 14, 2026 at 5:28 PM Neil Armstrong
>> <neil.armstrong at linaro.org> wrote:
>>>
>>> On 10/14/26 10:20, Chen-Yu Tsai wrote:
>>>> The DWC3 controller can operate in host mode. It does so with a XHCI
>>>> compliant host controller. The XHCI has two downstream ports, one for
>>>> HS and one for SS. USB downstream ports start from 1, not 0.

[...]


>> IMHO having consistent numbering across controller types would be
>> better. This avoids making the USB core and hub code deal with more
>> exceptions, and also easier to understand and write device trees.
> 
> I was in the impression the port number not necessarily reflects
> an actual physical numbering, and can be a logical number we would
> then map in the kernel.
> 
> I don't see any issue here having base 0 for the bindings and then
> converting it to base 1 for the XHCI port numbering.

I thought base1 comes from the USB spec and not just XHCI?

Konrad