Ethernet reinit on phyCORE hangs the device

[Andrej Picej]

Hi all,

when testing barebox ethernet on i.MX6 (phyCORE) we encountered a bug:
the ethernet re-init on barebox doesn't work! If we do:
$ ifup eth0
$ ifdown eth0
and then:
$ ifup eth0
$ ping HOST_IP
the device hangs and can only be saved by resetting the board manually.

We narrowed the problem down to the "fec_tx_task_enable". It seems that 
enabling tx task with writing to TDAR reg hangs the device shortly after.

Did you guys maybe encounter something similar on i.MX6 boards or on any 
other boards?

I guess this is a really specific problem as people don't normally do 
ifup/ifdown with ethernet in bootloader :D.

Do you have any idea what could be the reason or how could this be solved?
Any useful information would be greatly appreciated.

Using barebox v2022.02.

Best Regards,
Andrej