>> You might also like to try the 4.17.2 kernel
>> on it's ways to testing "dnf --enablerepo=updates-testing upgrade
FYI, I tried the 4.17.2 kernel and still no USB devices are seen.
So I managed to find mine and have a try.
I'm still seeing the same issues I saw previously  but with a
couple of power cycles it eventually booted to a point I could login.
With a bit of poking around each time before it died I had a bit of a
play and a few reboots before the file system was no longer
recoverable I did mange to work out the following about usb. It
actually works if you have the device plugged in from the outset, I
tried an input device and a usb stick. So I suspect a GPIO or
regulator isn't wired up via the DT properly.
This was with F-28 GA release so I'm going to try the next nightly
rawhide with 4.18 and a newer u-boot when I get a moment.