Re: [PATCH V2 5/6] PM / domain: Save/restore performance state at runtime suspend/resume

From: Kevin Hilman
Date: Fri Feb 17 2017 - 18:58:24 EST

Viresh Kumar <viresh.kumar@xxxxxxxxxx> writes:

> With runtime PM, the devices get suspended while the system is up and
> running in order to save power. At such times, it is important to
> re-evaluate the required performance state of the domain, in order to
> choose a lower state if possible.
> This patch updates the genpd suspend/resume callbacks to do that.
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

Doesn't this assume that a device in the domain would need to change
performance state while runtime suspended. How would that happen?

Rather than adding this here, I would think that drivers would instead
remove any QoS requests before going into runtime suspend, which would
trigger an update before runtime suspending.