Re: [REGRESSION] usb: acpi: add device link between tunneled USB3 device and USB4 Host Interface

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi Harry,

On Wed, Oct 02, 2024 at 01:42:29PM -0400, Harry Wentland wrote:
> I was checking out the 6.12 rc1 (through drm-next) kernel and found
> my system hung at boot. No meaningful message showed on the kernel
> boot screen.
> 
> A bisect revealed the culprit to be
> 
> commit f1bfb4a6fed64de1771b43a76631942279851744 (HEAD)
> Author: Mathias Nyman <mathias.nyman@linux.intel.com>
> Date:   Fri Aug 30 18:26:29 2024 +0300
> 
>     usb: acpi: add device link between tunneled USB3 device and USB4 Host Interface
> 
> A revert of this single patch "fixes" the issue and I can boot again.
>     
> The system in question is a Thinkpad T14 with a Ryzen 7 PRO 6850U CPU.
> It's running Arch Linux but I doubt that's of consequence.
> 
> lspci output:
>     https://gist.github.com/hwentland/59aef63d9b742b7b64d2604aae9792e0
> acpidump:
>     https://gist.github.com/hwentland/4824afc8d712c3d600be5c291f7f1089
> 
> Mario suggested I try modprobe.blacklist=xhci-hcd but that did nothing.
> Another suggestion to do usbcore.nousb lets me boot to the desktop
> on a kernel with the faulty patch, without USB functionality, obviously.
> 
> I'd be happy to try any patches, provide more data, or run experiments.

Do you boot with any device connected?

Second thing that I noticed, though I'm not familiar with AMD hardware,
but from your lspci dump, I do not see the PCIe ports that are being
used to tunnel PCIe. Does this system have PCIe tunneling disabled
somehow?

You don't see anything on the console? It's all blank or it just hangs
after some messages?

Can you also provide full dmesg with that commit reverted with
"thunderbolt.dyndbg=+p" in the kernel command line?