Re: [RFC] cpuidle - remove the power_specified field in the driver

From: Rafael J. Wysocki
Date: Mon Dec 10 2012 - 17:36:45 EST


On Monday, December 10, 2012 11:09:58 AM Julius Werner wrote:
> Hi,
>
> What is the current status of this? Daniel, do you think you have got
> enough feedback to submit a definitive patch for this? Rafael, would
> you approve of such a change?

I need to talk to Len about that before I give you a reliable answer.

Thanks,
Rafael


> The bug with dynamically added C-states that is tied to this still
> hurts the battery life for some users across all distros every day, so
> I think it would be valuable to get a consistent solution into the
> mainline soon before everyone has to roll their own.
>
> On 11/12/2012 09:26 PM, Daniel Lezcano wrote:
> > This patch follows the discussion about reinitializing the power usage
> > when a C-state is added/removed.
> >
> > https://lkml.org/lkml/2012/10/16/518
> >
> > We realized the power usage field is never filled and when it is
> > filled for tegra, the power_specified flag is not set making all these
> > values to be resetted when the driver is initialized with the set_power_state
> > function.
> >
> > Julius and I feel this is over-engineered and the power_specified
> > flag could be simply removed and continue assuming the states are
> > backward sorted.
> >
> > The menu governor select function is simplified as the power is ordered.
> > Actually the condition is always true with the current code.
> >
> > The cpuidle_play_dead function is also simplified by doing a reverse lookup
> > on the array.
> >
> > The set_power_states function is removed as it does no make sense anymore.
> >
> > Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> > ---
> > drivers/cpuidle/cpuidle.c | 17 ++++-------------
> > drivers/cpuidle/driver.c | 25 -------------------------
> > drivers/cpuidle/governors/menu.c | 8 ++------
> > include/linux/cpuidle.h | 2 +-
> > 4 files changed, 7 insertions(+), 45 deletions(-)
> >
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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