p...@whooppee.com (Paul Goyette) writes: >Don't forget to deregister the device if the xxx_attach() later exits...
I think the point was to not do this, so that a failed attach doesn't prevent the system from entering sleep mode. Here, calling pmf_register first on attachment is then required, but then you have to think on how to handle failures of pmf_register. You wouldn't want the device to fail attachment in that case, but rather accept that you cannot suspend in that situation. You also have to think about drivers that are left only partially configured after a failed attachment. That is already unsafe with drivers that only do a dummy pmf registration, but what about hardware that actually needs support routines ? Registering these for a partially configured driver may not work either. Unregister again and register dummy routines ? An easy solution would be to make attach actually fail, autoconf could then detached the driver immediately and it won't interfere with pmf. N.B. if autoconf API is changed, you could also integrate pmf into cfattach.
