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SubjectRe: [PATCH 2/7] pm: at91: pm_suspend: add the WFI support for ARMv7
Hello.

On 1/26/2015 1:06 PM, Wenyou Yang wrote:

> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> ---
> arch/arm/mach-at91/pm_suspend.S | 54 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 53 insertions(+), 1 deletion(-)

> diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
> index 122a3f1..e796722 100644
> --- a/arch/arm/mach-at91/pm_suspend.S
> +++ b/arch/arm/mach-at91/pm_suspend.S
> @@ -53,6 +53,58 @@ mode .req r6
> beq 1b
> .endm
>
> +/*
> + * Put the processor to enter the WFI state
> + */
> + .macro _do_wfi
> +
> +#if defined(CONFIG_CPU_V7)
> + /*
> + * Execute an ISB instruction to flush the pipeline to ensure
> + * that all of operations have beem completed.

Been.

> + */
> + isb
> +
> + /*
> + * Execute an ISB instruction to ensure that all of the

ISB again, while you're executing DSB/DMB?

> + * CP15 register changes have been committed.
> + */
> + dsb
> + dmb
> +
> + /* Disable the processor's clock */
> + mov tmp1, #AT91_PMC_PCK

What's 'tmp1'? Is that a register name?

> + str tmp1, [pmc, #AT91_PMC_SCDR]
> +
> + /* Execute a WFI instruction */

Self-obvious comment, I'd say...

> + wfi @ Wait For Interrupt
> +
> + /*
> + * CPU can specualatively prefetch the instructions

Speculatively.

[...]

WBR, Sergei



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