iMAC with Broadcom 14e4-1686 BCM57766 : link status down

[speleo14]

(2017-06-13 15:24)NiKiZe Wrote:  

(2017-06-13 14:44)mastacontrola Wrote:  I don't know if it's a problem we in the iPXE community can fix or if we actually do need to talk with Apple to try to get a suitable fix for this.

As has already been confirmed to be an issue with newer firmware, but not with older firmware, so contacting Apple should definitely be done.
With that said this is also an issue on non Apple machines if the NIC ends up in the same state. What is needed is to find out which register in the NIC is affected, so 2 machines with the same nic (one working firmware and one with issues) and then dumping the nics registers might give information about what needs to be done. and maybe comparing this to some other driver (linux?) but even better if we could get datasheets.

I have enough machines with different firmware and NIC, so if I can help here, please let me know. However, I'm afraid I'd need some advice what to do exactly and how to do it.
I may be able to open a case with Apple engineering, but this will still need some time.