USB Transfers Hang Part-Way Through

[ghalfacree]

Describe the bug
Tried to upgrade my FunKey S to 2.3.0. Did the usual: hooked it up to my desktop (64-bit Ubuntu 20.04), mounted USB, downloaded the .fwu file, dragged and dropped. Only this time... it stalled at the end of the transfer. sync didn't work, ejecting on the desktop side didn't work, and ejecting on the FunKey didn't work.

I checked with iotop that there was no data still being written, left it in the hope it'd recover, but nothing. Eventually I had to pull the USB cable... which triggered an update using an apparently partial update file.

Naturally, that didn't go well. Rebooted into the recovery screen, but I couldn't select any options from the text menu. Neither did the network spring into life - Ubuntu kept giving me errors about being unable to bring up the network interface.

So, downloaded the .img file, took the FunKey S apart, removed the microSD, copied all my ROM files and the like off, flashed the image to the microSD, reinserted the microSD, reassembled the FunKey, let it boot, mounted USB, and copied all the files back.

Except it didn't work, and hung after copying 245 of 359 files. Same symptoms as before: won't eject on either side. Not sure what's going on, to be honest, but it's annoying - if USB transfer doesn't work, that means I'm going to have to take the thing apart every time I want to update the firmware or load a new game...

To Reproduce
Steps to reproduce the behaviour:

1. Mount USB.
2. Transfer a decent number of files or a decently-large file.
3. Wait.
4. Try to eject.

Expected behaviour
Files write fine, device ejects fine.

Desktop (please complete the following information):

• Ubuntu 20.04 64-bit

[ghalfacree]

funkeydmesg.txt