fixes for kernel module

[thillux]

I tested the kernel module and saw, that it did not recover from health errors, when repeatedly hot-plugging the USB RNG. After some testing and consulting Claude Code, the following seems to work for me now.

Flashing the vendor and product IDs did not succeed without setting the old IDs to match on. I updated the README.md accordingly.

[thillux]

Unrelated: Thanks for providing this nice piece of hardware and software!

[thillux]

The EEPROM programming config listed in the kernel module also currently does not reprogram the serial number.
I changed that locally by setting use_serial=true and setting the previous serial number of the stick again.

[thillux]

Still WIP, unmarking draft again, when ready.

[thillux]

I'm currently debugging hangs of reading from /dev/hwrng backed by infnoise when unplugging the device mid read. IMHO the read should fail after some time.

[thillux]

I'm no longer able to put my system in a deadlock with the kernel module. You may have a look now 👍

[thillux]

Hi @manuel-domke,

this PR fixes the following issues I experienced:

• unplugging the TRNG while reading bytes from it (e.g. via /dev/hwrng) lead to deadlocks
• the device sometimes blocked forever when recovering temporary health issues (e.g. on startup after reboot or unplug)
• the device needed some recovery cycles on reboot

Therefore I tested many unplugs and reboots until I was satisfied by no errors in dmesg and no blocking behavior indicating a deadlock.

BR
Markus

[thillux]

Feel free to anything you want with this PR (apply partially, squash together, ...).