On Friday, May 09, 2014 04:13:56 PM Pavel Machek wrote:
> On Fri 2014-05-09 13:26:47, Rafael J. Wysocki wrote:
> > On Friday, May 09, 2014 09:38:35 AM Pavel Machek wrote:
> > > On Mon 2014-05-05 00:51:54, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> > > >
> > > > If freeze_enter() is called, we want to bypass the current cpuidle
> > > > governor and always use the deepest available (that is, not disabled)
> > > > C-state, because we want to save as much energy as reasonably possible
> > > > then and runtime latency constraints don't matter at that point, since
> > > > the system is in a sleep state anyway.
> > >
> > > Would there be way to pass the parameter "go to deepest" instead of adding
> > > global state for this?
> >
> > I'm not sure what you mean? A parameter of what in particular? And where
> > to pass it?
>
> Currently the code is:
>
> static void freeze_enter(void)
> {
> + cpuidle_use_deepest_state(true);
> cpuidle_resume();
> wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
> cpuidle_pause();
> + cpuidle_use_deepest_state(false);
> }
>
> . I believe it would be better if you did
>
> cpuidle_resume(GOTO_DEEPEST_C_STATE)
>
> instead of having global state.
That's a good idea actually. I'll do that on top of the $subject patch.
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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