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

["Michał Pecio" <michal.pecio@gmail.com>]

> No 'quiet' option and with loglevel at 4 I still don't seem to see
> any prints.
What's the loglevel of your printks? If they are INFO, NOTICE or DEBUG
they will not appear on loglevel 4. In particular, the patch you are
testing added a dev_info, which is INFO and will not show on level 4.
I would simply change it to dev_err, then it should show.

> Interestingly if I set loglevel to 6 my boot gets much farther but
> then gets stuck at "A start job is running for Load Kernel Modules
> with ever increasing timeout values".
So the kernel isn't crashing, but probably some module gets stuck on
initialization and 'modprobe' never completes.

Not sure if it really gets much further or simply prints more noise?

If Magic SysRq doesn't work, maybe systemd simply disabled it? It does
so by default, unless overriden by custom config files. It looks like
your root FS gets mounted, so those configs may work.

You could also try blacklisting xhci_pci. I don't know what sort of
kernel config you are using, but on Arch Linux xhci_hcd is built-in so
your blacklisting attempt failed, but xhci_pci is a loadable module.

If this helps, then the next logical step is to 'modprobe xhci_pci'
while running 'dmesg -w' and see what happens.

Regards,
Michal