Hi Sergey, > > The only thing I'd be worried about is that different implementations > > use it for different meanings, but I guess that's not that big a deal? > > The spectrum of sane use of the IFLA_PARENT_DEV_NAME attribute by > various subsystems and (or) drivers will be quite narrow. It should do > exactly what its name says - identify a parent device. Sure, I was more worried there could be multiple interpretations as to what "a parent device" is, since userspace does nothing but pass a string in. But we can say it should be a 'struct device' in the kernel. > We can not handle the attribute in the common rtnetlink code since > rtnetlink does not know the HW configuration details. That is why > IFLA_PARENT_DEV_NAME should be handled by the RTNL ->newlink() > callback. But after all the processing, the device that is identified > by the IFLA_PARENT_DEV_NAME attribute should appear in the > netdev->dev.parent field with help of SET_NETDEV_DEV(). Eventually > RTNL will be able to fill IFLA_PARENT_DEV_NAME during the netdevs dump > on its own, taking data from netdev->dev.parent. I didn't do that second part, but I guess that makes sense. Want to send a follow-up patch to my other patch? I guess you should've gotten it, but if not the new series is here: https://lore.kernel.org/netdev/20210602082840.85828-1-johannes@xxxxxxxxxxxxxxxx/T/#t > I assume that IFLA_PARENT_DEV_NAME could replace the IFLA_LINK > attribute usage in such drivers as MBIM and RMNET. But the best way to > evolve these drivers is to make them WWAN-subsystem-aware using the > WWAN interface configuration API from your proposal, IMHO. Right. johannes
