Re: [PATCH] PM OMAP3: Change omap3_save_secure_ram to be called only during init

[Kevin Hilman <khilman@deeprootsystems.com>]

Tero Kristo <tero.kristo@nokia.com> writes:

> This function is now called only once during the initialization of the device
> and consequent sleep cycles will re-use the same saved contents for secure
> RAM. Users who need secure services should do secure RAM saving before
> entering off-mode, if a secure service has been accessed after last save.
>
> Signed-off-by: Tero Kristo <tero.kristo@nokia.com>

You explain what you're doing, but you don't explain why.

Is there a large latency involved in this save/restore that you're
trying to eliminate for the no-secure-services case?

Kevin

> ---
>  arch/arm/mach-omap2/pm34xx.c |   19 ++++++++++++++++++-
>  1 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 4223622..b8cf5f2 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -127,6 +127,12 @@ static void omap3_core_restore_context(void)
>  	omap_dma_global_context_restore();
>  }
>  
> +/*
> + * FIXME: This function should be called before entering off-mode after
> + * OMAP3 secure services have been accessed. Currently it is only called
> + * once during boot sequence, but this works as we are not using secure
> + * services.
> + */
>  static void omap3_save_secure_ram_context(u32 target_mpu_state)
>  {
>  	u32 ret;
> @@ -349,7 +355,6 @@ void omap_sram_idle(void)
>  					     OMAP3_PRM_VOLTCTRL_OFFSET);
>  			omap3_core_save_context();
>  			omap3_prcm_save_context();
> -			omap3_save_secure_ram_context(mpu_next_state);
>  		}
>  		/* Enable IO-PAD wakeup */
>  		prm_set_mod_reg_bits(OMAP3430_EN_IO, WKUP_MOD, PM_WKEN);
> @@ -923,6 +928,18 @@ int __init omap3_pm_init(void)
>  	}
>  	omap3_save_scratchpad_contents();
>  
> +	if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
> +		local_irq_disable();
> +		local_fiq_disable();
> +
> +		omap_dma_global_context_save();
> +		omap3_save_secure_ram_context(PWRDM_POWER_ON);
> +		omap_dma_global_context_restore();
> +
> +		local_irq_enable();
> +		local_fiq_enable();
> +	}
> +
>  err1:
>  	return ret;
>  err2:
> -- 
> 1.5.4.3
>
> --
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