Hi,
On 06/01/2017 at 14:59:45 +0800, Wenyou Yang wrote :
> For the SoCs such as SAMA5D2 and SAMA5D4 which have L2 cache,
> flush the L2 cache first before entering the cpu idle.
>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> ---
>
> arch/arm/mach-at91/pm.c | 19 +++++++++++++++++++
> drivers/memory/atmel-sdramc.c | 1 +
> 2 files changed, 20 insertions(+)
>
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
> index b4332b727e9c..1a60dede1a01 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -289,6 +289,24 @@ static void at91_ddr_standby(void)
> at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
> }
>
> +static void at91_ddr_cache_standby(void)
> +{
> + u32 saved_lpr;
> +
> + flush_cache_all();
> + outer_disable();
> +
> + saved_lpr = at91_ramc_read(0, AT91_DDRSDRC_LPR);
> + at91_ramc_write(0, AT91_DDRSDRC_LPR, (saved_lpr &
> + (~AT91_DDRSDRC_LPCB)) | AT91_DDRSDRC_LPCB_SELF_REFRESH);
> +
> + cpu_do_idle();
> +
> + at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr);
> +
> + outer_resume();
> +}
> +
Seems good to me. Did you measure the added latency on sama5d3 if you
add the cache operations in at91_ddr_standby instead of having a new
function?
--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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