I was pleased to fine that the ixgbe driver had good support for the 10GBit interfaces on the Atom C3708 device I was using. However, the same is not true of the 2.5GBit interfaces on the Atom C3508. The PCI IDs on these interfaces are very similar -- 8086:15cf on the C3508 vs 8086:15ce on the C3708. Modifying the ixgbe driver to simply treat 8086:15cf almost works -- the 4 Ethernet interfaces are discovered and *something* happens when I plug in a Gigiabit ethernet cable into the SFP port:
[ 269.233242] ixgbe 0000:0c:00.0 eth1: NIC Link is Up 1 Gbps, Flow Control: RX/ TX [ 269.240733] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready [ 269.337230] ixgbe 0000:0c:00.0 eth1: NIC Link is Down [ 289.682588] ixgbe 0000:0c:00.1 eth2: detected SFP+: 6 [ 392.859888] ixgbe 0000:0c:00.0: removed PHC on eth1 [ 393.497099] ixgbe 0000:0c:00.1: removed PHC on eth2 [ 394./MA257214] ixgbe 0000:0d:00.0: removed PHC on eth3 [ 394.867122] ixgbe 0000:0d:00.1 eth4: NIC Link is Up 1 Gbps, Flow Control: RX/TX [ 394.889384] ixgbe 0000:0d:00.1: removed PHC on eth4 Clearly not all is well, as could be expected -- I'm sure there's a real reason why these are separate PCI IDs. Is there someone out there that can point me at docs I can use to support the device myself, or does anyone know if support is coming? Should this device be considered an X550 or is this a different device fundamentally (should I not use the Intel X550 docs as a reference, if I were to hunt down some documentation about the difference between these parts?)
