Kalle Jokiniemi <kalle.jokini...@digia.com> writes:

> According to measurements, reading the previous state of PER
> domain after wfi takes ~11us on OPP2.
>
> Removed this unneccessary latency from cases where we know
> PER power domain did not try to enter off mode.
>
> Signed-off-by: Kalle Jokiniemi <kalle.jokini...@digia.com>

Looks good, pulling into PM branch.

But still amazed at such a *huge* latency to read that register.

Kevin

> ---
>  arch/arm/mach-omap2/pm34xx.c |   19 +++++++++++++------
>  1 files changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 237c819..b70ea19 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -489,12 +489,19 @@ void omap_sram_idle(void)
>  
>       /* PER */
>       if (per_next_state < PWRDM_POWER_ON) {
> -             per_prev_state = pwrdm_read_prev_pwrst(per_pwrdm);
> -             if (per_prev_state == PWRDM_POWER_OFF) {
> -                     omap3_per_restore_context();
> -                     omap3_gpio_restore_pad_context(0);
> -             } else if (per_next_state == PWRDM_POWER_OFF)
> -                     omap3_gpio_restore_pad_context(1);
> +             if (per_next_state == PWRDM_POWER_OFF) {
> +                     /*
> +                      * Reading the prev-state takes long time (1...@opp2),
> +                      * only do it, if we really tried to put PER in OFF
> +                      */
> +                     per_prev_state = pwrdm_read_prev_pwrst(per_pwrdm);
> +                     if (per_prev_state == PWRDM_POWER_OFF) {
> +                             omap3_per_restore_context();
> +                             omap3_gpio_restore_pad_context(0);
> +                     } else if (per_next_state == PWRDM_POWER_OFF) {
> +                             omap3_gpio_restore_pad_context(1);
> +                     }
> +             }
>               omap2_gpio_resume_after_idle();
>               omap_uart_resume_idle(2);
>               if (per_state_modified)
> -- 
> 1.5.4.3
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