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I think it's a good direction. I couldn't find a way to fix it in devlink and the problem does seem specific to netdevsim. > AFAIU we only need the bus to remain loaded for nsim_bus_dev_release > to exist? That's my understanding as well. > What if we split netdevsim into two modules, put the bus stuff in a > new module called netdevsim_bus, and leave the rest (driver) in just > netdevsim. That way we can take a ref on netdevsim_bus until all > devices are gone, and still load / unload netdevsim. With unload > resulting in all devices getting auto-deleted. > > I haven't looked in detail so maybe you'll immediately tell me it won't > work, but I'm guessing this is how "real" buses work avoid the problem? At least with PCI (which I believe is the bus backing most devlink users), the release callback is builtin - not part of a module - so this problem can't happen there. Anyway, I will explore this direction. Thanks!