Detect USB disconnect

[Sec42]

I would like to detect it on the protocol level (MSC unmount, CDC close), but found no way.

As a workaround the hardware USB disconnect would be possible, but I haven't even found a way to do this yet.

Any hints welcome

[schneider42]

Maybe a timeout on the SOF indicator?

[Sec42]

we worked around it for now by a last-sector-write detection.