> Devicetree to the rescue! Yes, exactly. We have good, standardised descriptions for most of this in device tree. And phylink can handle SFP and SFP+. Nobody has worked on QSFP yet, since phylink has mostly been pushed by the embedded world and 40G is not yet popular in the embedded world. > Entertaining the use of ACPI without any firmware abstraction for this > hardware really feels like a square peg / round hole situation, so I'm > assuming somebody's telling you that you need it "FOAR ENTAPRYZE". Who > is it and can you tell them to bog off? The issues here is that SFPs are appearing in more and more server systems, replacing plain old copper Ethernet. If the boxes use off the shelf Mellanox or Intel PCIe cards, it is not an issue. But silicon vendors are integrating this into the SoC in the ARM way of doing things, memory mapped, spread over a number of controllers, not a single PCIe device. Maybe we need hybrid systems. Plain, old, simple, boring things like CPUs, serial ports, SATA, PCIe busses are described in ACPI. Complex interesting things are in DT. The hard thing is the interface between the two. DT having a phandle to an ACPI object, e.g a GPIO, interrupt or an i2c bus. Andrew
