What's on the other end of gmac1?
Datasheet by-line for ethernet:
Ethernet HSGMII x 2; integrate 1G PHY for extender
Only support SGMII-1 or internal-GBE due to MAC sharing
ALso I got very confused until I checked the forum and found that this wasn't supported until I found this on the forum hahaha.
I don't see where it's got a phy on the DTS? It's HSGMII? What are you trying to link to on the other end? Openwrt one had a phy on mdio bus that was 2500-base-x? I'd need to do more looking at what various other 2.5gb enabled devices have on other targets....