Messages in this thread | | | Date | Mon, 26 Jan 2015 16:05:14 +0300 | From | Sergei Shtylyov <> | Subject | Re: [PATCH 2/7] pm: at91: pm_suspend: add the WFI support for ARMv7 |
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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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