Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH V2 3/5] cpuidle: idle: menu: Don't reflect when a state selection failed | Date | Wed, 29 Oct 2014 22:11 +0100 |
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On Wednesday, October 29, 2014 09:54:43 AM Kevin Hilman wrote: > Daniel Lezcano <daniel.lezcano@linaro.org> writes: > > > On 10/28/2014 08:01 AM, Preeti Murthy wrote: > >> On Thu, Oct 23, 2014 at 2:31 PM, Daniel Lezcano > >> <daniel.lezcano@linaro.org> wrote: > >>> In the current code, the check to reflect or not the outcoming state is done > >>> against the idle state which has been chosen and its value. > >>> > >>> Instead of doing a check in each of the reflect functions, just don't call reflect > >>> if something went wrong in the idle path. > >>> > >>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> > >>> Acked-by: Nicolas Pitre <nico@linaro.org> > >>> --- > >>> drivers/cpuidle/governors/ladder.c | 3 +-- > >>> drivers/cpuidle/governors/menu.c | 4 +--- > >>> kernel/sched/idle.c | 3 ++- > >>> 3 files changed, 4 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c > >>> index fb396d6..c0b36a8 100644 > >>> --- a/drivers/cpuidle/governors/ladder.c > >>> +++ b/drivers/cpuidle/governors/ladder.c > >>> @@ -165,8 +165,7 @@ static int ladder_enable_device(struct cpuidle_driver *drv, > >>> static void ladder_reflect(struct cpuidle_device *dev, int index) > >>> { > >>> struct ladder_device *ldev = &__get_cpu_var(ladder_devices); > >>> - if (index > 0) > >>> - ldev->last_state_idx = index; > >>> + ldev->last_state_idx = index; > >>> } > >>> > >>> static struct cpuidle_governor ladder_governor = { > >>> diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c > >>> index a17515f..3907301 100644 > >>> --- a/drivers/cpuidle/governors/menu.c > >>> +++ b/drivers/cpuidle/governors/menu.c > >>> @@ -365,9 +365,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, > >>> static void menu_reflect(struct cpuidle_device *dev, int index) > >>> { > >>> struct menu_device *data = &__get_cpu_var(menu_devices); > >>> - data->last_state_idx = index; > >>> - if (index >= 0) > >>> - data->needs_update = 1; > >>> + data->needs_update = 1; > >> > >> Why is the last_state_idx not getting updated ? > > > > Oups, right. This is missing. > > > > Thanks for pointing this out. > > > > By the way, I don't think a back end driver is changing the selected > > state currently and I am not sure this is desirable since we want to > > trust the state we are going (as a best effort). > > FYI, the OMAP3 backend driver can does not always obey the selected > state, and will return a different state than the one requested.
The ACPI driver can do that as well.
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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