For some time now, u-boot forces this board into master mode, based on an assumption that the PHY chip simply cannot work in slave mode.
Later, some drivers and boards has had success in tuning RX/TX internal delays either in MAC or in PHY. If someone wants to try test if perhaps the Lime2 Rev C board _can_ work in slave mode, if differently calibrated, then here's how to get started: * Build u-boot _without_ option RTL8211X_PHY_FORCE_MASTER=y * Install ethtool 5.8 or newer to probe or set master/slave mode To try calibrate delays at MAC: * Build u-boot with option CONFIG_GMAC_TX_DELAY=N at various values To try calibrate delays at PHY: * compile device-tree file with option phy-mode = "rgmii-id" * try set RX/TX values using ethtool 5.8 or newer * alternatively set RX/TX values in device-tree More information about this at https://linux-sunxi.org/Olimex_A20-OLinuXino-Lime2#GMAC_quirks - Jonas -- * Jonas Smedegaard - idealist & Internet-arkitekt * Tlf.: +45 40843136 Website: http://dr.jones.dk/ [x] quote me freely [ ] ask before reusing [ ] keep private
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