On 6/23/24 18:02, Andrew Lunn wrote: >>> If there is no netdev, what is the point of putting it into loopback? >>> How do you send packets which are to be looped back? How do you >>> receive them to see if they were actually looped back? >>> >>> Andrew >> >> To run RDMA test in loopback. > > What is special about your RDMA? Why do you need something which other > vendors don't? Please solve this problem for all RDMA devices, not > yours. > > This all part of the same thing with respect to module > parameters. Vendors would add module parameters for something. Other > vendors would have the same concept, but give it a different name, > different values. It was all poorly documented. You had to read the > kernel sources to figure out what kernel module parameters do. Same > goes for debugfs, driver values in /proc, /sysfs or /debugfs. So for > years we have been pushing back on things like this. > > If you have something which is unique to your hardware, no other > vendor is ever going to have the same, then you can make an argument > for something driver specific in /debugfs. But RDMA loopback tests is > clearly not specific to your driver. Extend the KAPI and tools to > cover this, document the KAPI, write the man page, and let other > vendors implement the little bit they need in their driver, so users > have a uniform way of doing things over a rather of devices. > > You will get a lot of pushback on everything in /debugfs, so please > review them all with this in mind. > > Andrew I see your point and I'll keep that in mind. For these kinds of configurations we can use devlink instead of debugfs.