We have a custom board and a Variscite DART-MX6, both equipped with the Micrel KSZ9031 Gigabit Ethernet Tranceiver. On both I have the same issue.
When hitting suspend, the LEDs do not turn off, but light up constantly at a dimmed down level. If the ethernet cable is not connected and the lights are off when I invoke suspend, it still decides to light up again.
I've looked at the Micrel datasheet, as well as the linux drivers for fec/micrel, but find nothing to "defend" this kind of behaviour, so I just wanted to say it out loud here in case someone has a clue.