Re: [PATCH v6 02/20] liveupdate: luo_core: integrate with KHO

You can avoid that complexity if you register the device with a different
fops, but that's technicality.

Your point about treating the incoming FDT as an underlying resource that
failed to initialize makes sense, but nevertheless userspace needs a
reliable way to detect it and parsing dmesg is not something we should rely
on.

I see two solutions:

1. LUO fails to retrieve the preserved data, the user gets informed by
not finding /dev/liveupdate, and studying the dmesg for what has
happened (in reality in fleets version mismatches should not be
happening, those should be detected in quals).
2. Create a zombie device to return some errno on open, and still
study dmesg to understand what really happened.

I think that 1 is better

Pasha