Re: [PATCH v2 0/4] DWC3 link tunneling state reporting

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Jul 15, 2026, Konrad Dybcio wrote:
> On 7/15/26 2:29 PM, 'Konrad Dybcio' via USB4 - Upstream wrote:
> > Currently, retrieving the tunneled/native state of a running port is
> > only possible on Intel XHCI hosts. This series extends that to CIO-
> > capable DWC31 controllers (see [1]).
> > 
> > Note that this patchset only results in the correct udev->tunnel_mode
> > value being assigned. Creating the device links (which requires this
> > information) between the USB4 router and the USB3 controller does not
> > currently take place on DT-based platforms, but that will be amended
> > in a follow-up patchset.
> > 
> > Tested on a Qualcomm X1E80100 CRD board, with a (currently) out-of-tree
> > set of drivers.
> > 
> > [1] I'm not entirely sure about the DWC version range (particularly
> >     wrt DWC32 and newer), so I limited it to a reasonable subset. I'll
> >     happily amend that.
> > 
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> > ---
> > Changes in v2:
> > - Add handling for XHCI v1.2's USB3 tunneling and PORTSC.TM for
> >   platforms that advertise it (!!! UNTESTED !!!, I have no access to
> >   HW that exposes this)
> > - Prefer the aforementioned cap over custom implementations
> > - Bail out of the DWC3-specific check if `usb4-host-interface` device
> >   property is absent - hence this now depends on:
> >   https://urldefense.com/v3/__https://github.com/devicetree-org/dt-schema/pull/196__;!!A4F2R9G_pg!Yp4eQxr_V48OU-fhHIAT1pJrvhKI2VbT19cN4M-3EHIA5K9G57Npd31Hs5MLCPneAJ3pxM3JzzaQ7Mc_8sTGV7KEa_bieEilDA$ 
> > 
> > - Link to v1: https://urldefense.com/v3/__https://patch.msgid.link/20260505-topic-dwc3_tunneling_state-v1-0-4aaa6c3c14cb@oss.qualcomm.com__;!!A4F2R9G_pg!Yp4eQxr_V48OU-fhHIAT1pJrvhKI2VbT19cN4M-3EHIA5K9G57Npd31Hs5MLCPneAJ3pxM3JzzaQ7Mc_8sTGV7KEa_bYNq9e3w$ 
> 
> +Cc Sven sorry, I forgot to include you..
> 
> Konrad

Thank you for the patch series!

Don't worry about the DWC32 version range. Newer controllers should
follow the xhci v1.2 spec. We can always apply fixes later as needed.

Thanks,
Thinh

ps. I'll be out of office tomorrow until 7/31. My response may be
delayed.