Re: Devices without power management support

[Taylor R Campbell <campbell+netbsd-tech-kern%mumble.net@localhost>]

> Date: Fri, 19 Aug 2022 01:22:39 +0000
> From: Emmanuel Dreyfus <manu%netbsd.org@localhost>
> 
> I have patches to move the pmf_device_register() earlier in xxx_attach()
> to workaround the problem in iwm(4) and ihidev(4) where I encounter the
> problem, but perhaps the problem could be worked around globaly, by not
> failing sleep mode if a driver did not call pmf_device_register()?

I think we should just make the device suspend/resume functions be
autoconf routines like match, attach, detach, and dispense with
pmf_device_register altogether.

FYI, moving pmf_device_register earlier can turn a working driver into
a broken driver, because right now there's nothing that prevents
suspend from happening before attach completes, and the suspend
routine may assume that attach has completed.

All that said: What is the failure mode you're seeing for ihidev that
blocks suspend?

(iwm(4) attach is flaky and needs to be rototilled, but I'd rather not
touch that on HEAD while martin's wifi branch is in progress.)