no console, so manually typing out trace output
ehci_sync_hc: tsleep() = 35
ehci_sync_hc: tsleep() = 35
ehci_sync_hc: tsleep() = 35
ehci_sync_hc: tsleep() = 35
kernel: protection fault trap, code=0
Stopped at usb_allocmem+0x175: cmpq %rbx,0(%rax)
ddb{0}> trace
usb_allocmem() at usb_allocmem+0x175
usbd_transfer() at usbd_transfer+0x67
usbd_do_request_flags() at usbd_do_request_flags+0xe4
usdb_get_desc() at usbd_new_desc+0x3b
usbd_new_device() at usbd_new_device+0x18d
uhub_port_connect() at uhub_port_connect+0x14e
uhub_explore() at uhub_explore+0x229
usb_explore() at usb_explore+0x153
usb_task_thread() at usb_task_thread+0xb6
end trace frame: 0x0, count: -9
thanks
