Re: [PATCH v2 2/4] usb: xhci: Honor PORTSC.TM if valid

[Konrad Dybcio]

On 7/31/26 12:51 PM, Mathias Nyman wrote:
> On 7/15/26 15:29, Konrad Dybcio wrote:
>> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
>>
>> Currently, the only way for the USB core to determine whether the link
>> is native or tunneled is via an Intel vendor-specific Extended
>> Capability.

[...]

>>   -    /* Don't try and probe this capability for non-Intel hosts */
>> +    /* Prefer the XHCI v1.2 ext_cap if advertised */
>> +    offset = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_USB3_TUNNELING);
>> +    if (offset) {
>> +        if (!(readl(base + offset) & XHCI_USB3_TUNNELING_SUPPORTED))
>> +            return USB_LINK_NATIVE;
>> +
> 
> The extcap 18 value won't change.
> We can read it once in xhci_gen_setup()/xhci_setup_port_arrays() and cache it.
> 
> here we would just check:
> 
> if  (xhci->portsc_tunnel_reporting) {
>     ..read portsc and return, as you do below

Got it

Konrad