On 28/09/18 16:39, Andrew Lunn wrote: > I wonder how true that will be in 5 years time, about reading the > manual? SFP sockets are starting to appear in consumer devices. There > are some Marvell SoC reference boards with SFP and SFP+. Broadcom also > have some boards with SFP. With time, SFP will move out of the data > centre and comms rack and into more everyday systems. In such context, > reading the manual becomes less likely. It would be nice to avoid a > future inconsistent mess caused be this sentiment now. > > Andrew I see where you're coming from, but if people start needing to manually configure FEC on their consumer devices, possibly we have bigger problems. Ethtool FEC control is for those situations where autoneg, autodetect, autoconfigure etc. don't work (e.g. owing to out-of-spec switches, or just a user wanting to disable FEC to save a few hundred nanos). I would hope that FEC won't show up in consumer gear until these kinds of problems have settled down somewhat.
Perhaps we can add something to the man page saying that not only can the semantics vary from NIC to NIC, but that the semantics for a given NIC might change in the future? Then if in five years' time we know what the Right Thing™ is, we can move everyone over to that (with appropriately *loud* release-notes). I think the alternative, of finding a set of semantics that fits everyone's hardware and covers everyone's requirements, is likely to be difficult (and probably require changing the ethtool API). -Ed
