Messages in this thread Patch in this message | | | Date | Wed, 28 Jan 2015 11:25:52 +0000 | From | Lorenzo Pieralisi <> | Subject | Re: [PATCH 2/7] pm: at91: pm_suspend: add the WFI support for ARMv7 |
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On Mon, Jan 26, 2015 at 10:06:01AM +0000, Wenyou Yang wrote:
Commit log please.
> 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
You will have to explain why you need this, really.
> + > +#if defined(CONFIG_CPU_V7) > + /* > + * Execute an ISB instruction to flush the pipeline to ensure > + * that all of operations have beem completed.
s/beem/been
> + */ > + isb > + > + /* > + * Execute an ISB instruction to ensure that all of the > + * CP15 register changes have been committed. > + */ > + dsb
This is a dsb not an isb.
> + dmb You have to explain why you need every single one of these barriers, otherwise I am NAKing this patch.
> + > + /* Disable the processor's clock */ > + mov tmp1, #AT91_PMC_PCK > + str tmp1, [pmc, #AT91_PMC_SCDR] > + > + /* Execute a WFI instruction */ > + wfi @ Wait For Interrupt
This one looks ok :)
> + > + /* > + * CPU can specualatively prefetch the instructions > + * so add NOPs after WFI. Sixteen NOPs as Cortex-A5 pipeline.
So what ? I suspect your issue is related to wfi completion on pending IRQ. I would like to know the details that describe the issue you are trying to solve here please.
> + */ > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > + nop > +#else > + mcr p15, 0, tmp1, c7, c0, 4 > +#endif
Tell us what's the problem you have to solve, first, then we will see how to fix it.
Thanks, Lorenzo
> + > + .endm > + > .text > > /* > @@ -181,7 +233,7 @@ sdr_sr_done: > > skip_disable_main_clock: > /* Wait for interrupt */ > - mcr p15, 0, tmp1, c7, c0, 4 > + _do_wfi > > tst mode, #AT91_PM_SLOW_CLOCK > beq skip_enable_main_clock > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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