On Friday, November 21, 2014 10:29:51 AM Daniel Lezcano wrote:
> The commit 8e92b6605d introduced the TIME_VALID flag for the C1 state
> if this one is a mwait state assuming the interrupt will be enabled
> before reading the end time of the idle state.
>
> The changelog of this commit mention a potential problem with the menu
> governor but not a real observation and I assume it described an old
> code as the commit is from 2008.
>
> I have been digging through the code and I didn't find any place where the
> interrupts are enabled before reading the time. Moreover with the changes
> in the meantime, we moved the time measurements in the cpuidle core as well
> as the interrupts enabling making sure the time is measured before the
> interrupt are enabled again in a single place.
>
> Remove this test as the time measurement is always valid for this
> state.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Well, I need Len to have a look at this.
> ---
> drivers/acpi/processor_idle.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 380b4b4..7afba40 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -985,8 +985,6 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
> state->flags = 0;
> switch (cx->type) {
> case ACPI_STATE_C1:
> - if (cx->entry_method != ACPI_CSTATE_FFH)
> - state->flags |= CPUIDLE_FLAG_TIME_INVALID;
>
> state->enter = acpi_idle_enter_c1;
> state->enter_dead = acpi_idle_play_dead;
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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