Comment # 20 on bug 1190411 from Roger Whittaker

Both boots:

# uname -r ; cat /proc/cmdline 
5.16.0-rc2-1.g696d453-default
BOOT_IMAGE=/boot/vmlinuz-5.16.0-rc2-1.g696d453-default
root=UUID=a81717ee-f292-40fc-8701-12e6e4591665 linux
resume=/dev/disk/by-uuid/957eb50f-8f08-47e1-b805-aba1235a78fc plymouth.enable=0
pci=nomsi iommu=off

# rmmod xhci_pci ; rmmod xhci_hcd ; rmmod xhci_pci_renesas

# modprobe xhci_pci ; modprobe xhci_hcd ; modprobe xhci_pci_renesas

(unplug and replug mouse, keyboard and two disks)

# dmesg

dmesg from each will now be attached.

Would you like me to also do the debugging stuff as in comment#12?