On Fri, 19 Aug 2022, Emmanuel Dreyfus wrote:
Hello
When a devices fails initialization, the xxx_attach() function may exit
early, before calling pmf_device_register().
The consequence is that any attempt to put the system to sleep fail with
a "Devices without power management support: ..." message.
Weird things happens, and I experienced situation where some devices
randomly or always fail initialization. This breaks sleeping mode.
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()?
Don't forget to deregister the device if the xxx_attach() later exits...
Of course the lack of a registered suspend handler may miss the expectation
of a system sleeping with reduced power, but on the other hand, being
unable to sleep at all means even less power reduction.
--
Emmanuel Dreyfus
m...@netbsd.org
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