Forcing devices into idle

Oliver Neukum oneukum at suse.com
Thu Jul 3 03:33:33 PDT 2025


On 03.07.25 12:08, Thierry Reding wrote:

> Any thoughts on how to solve this? Is the pm_runtime_{put,get}_sync()
> method acceptable? If not, are there other alternatives to achieve the
> same thing that I'm not aware of? Would it be useful to add a new set of
> APIs to force devices into an idle state (which could be semantically
> different from runtime suspend)? Or is this all too specific for any
> kind of generic API?

Basically what you need is what happens when the system prepares to
do a snapshot for S4. However, if you just perform FREEZE and then THAW,
devices will assume that user space has been frozen. You need a way
to substitute for that assumption.

Runtime power management is unlikely to be a fruitful approach to your
needs.

	HTH
		Oliver




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