XHCI Debug Capability

As explain in a previous post [1] I need a way to debug at kernel/driver level.

So one of the option is to use XHCI DbC Capability on target and A-to-A cable to the host. I found the soon-to-be-released driver for Linux and patch the kernel [2]. But it failed to detected the cable insertion.

So I took the XHCI specification to understand how this is working, but it didn't help much. And the author of the patch wasn't able to help me.

One last option is to try with Windows [3], but I don't have access to the debug version.

Does anyone of you already tried such a thing ?

Thanks a lot

[1] https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Unable-to-use-AMT-Serial-on-LAN/td-p/5862455

[2] https://patchwork.kernel.org/patch/9429009/

[3] https://msdn.microsoft.com/en-us/library/windows/hardware/hh439372(v=vs.85).aspx