Re: [PATCH 09/17] OMAP3: PM: Ack pending interrupts before entering suspend

[Kevin Hilman <khilman@deeprootsystems.com>]

<Tero.Kristo@nokia.com> writes:

>>-----Original Message-----
>>From: linux-omap-owner@vger.kernel.org 
>>[mailto:linux-omap-owner@vger.kernel.org] On Behalf Of ext Kevin Hilman
>>Sent: 20 October, 2009 20:31
>>To: Kristo Tero (Nokia-D/Tampere)
>>Cc: linux-omap@vger.kernel.org
>>Subject: Re: [PATCH 09/17] OMAP3: PM: Ack pending interrupts 
>>before entering suspend
>>
>>Tero Kristo <tero.kristo@nokia.com> writes:
>>
>>> From: Tero Kristo <tero.kristo@nokia.com>
>>>
>>> Suspending drivers may still generate interrupts just before 
>>their suspend is
>>> completed. Any pending interrupts here will prevent sleep.
>>>
>>> Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
>>
>>This could also be done in omap3_intc_prepare_idle() hook.
>
> I thought it is better to do this in suspend path only, because in
> normal sleep case we most likely don't want to miss any
> interrupts. 

Agreed, then I'd suggest doing this in omap3_intc_[suspend|resume]()
hooks.

> In suspend case, we usually want to enter the suspend no
> matter what, and this is used here only to clean up the mess left by
> some of the drivers. The GPT case is one of the main things we try
> to fix here.

So is this still needed with the GPTIMER fix in PATCH 8/17?

If there are other drivers having delayed interrupt triggering, it
sounds like the drivers need to be fixed instead of this brute force
approach.

Kevin

>
>>
>>> ---
>>>  arch/arm/mach-omap2/irq.c              |    2 +-
>>>  arch/arm/mach-omap2/pm34xx.c           |    2 ++
>>>  arch/arm/plat-omap/include/mach/irqs.h |    1 +
>>>  3 files changed, 4 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/irq.c b/arch/arm/mach-omap2/irq.c
>>> index aceedd8..4ed05e9 100644
>>> --- a/arch/arm/mach-omap2/irq.c
>>> +++ b/arch/arm/mach-omap2/irq.c
>>> @@ -101,7 +101,7 @@ static int omap_check_spurious(unsigned int irq)
>>>  }
>>>  
>>>  /* XXX: FIQ and additional INTC support (only MPU at the moment) */
>>> -static void omap_ack_irq(unsigned int irq)
>>> +void omap_ack_irq(unsigned int irq)
>>>  {
>>>  	intc_bank_write_reg(0x1, &irq_banks[0], INTC_CONTROL);
>>>  }
>>> diff --git a/arch/arm/mach-omap2/pm34xx.c 
>>b/arch/arm/mach-omap2/pm34xx.c
>>> index 5854fa7..6a41811 100644
>>> --- a/arch/arm/mach-omap2/pm34xx.c
>>> +++ b/arch/arm/mach-omap2/pm34xx.c
>>> @@ -778,6 +778,8 @@ static int omap3_pm_suspend(void)
>>>  
>>>  	omap_uart_prepare_suspend();
>>>  
>>> +	/* Ack pending IRQs, as a pending IRQ will cause the 
>>suspend to fail */
>>> +	omap_ack_irq(0);
>>>  	regset_save_on_suspend = 1;
>>>  	omap_sram_idle();
>>>  	regset_save_on_suspend = 0;
>>> diff --git a/arch/arm/plat-omap/include/mach/irqs.h 
>>b/arch/arm/plat-omap/include/mach/irqs.h
>>> index 2473910..d56be1c 100644
>>> --- a/arch/arm/plat-omap/include/mach/irqs.h
>>> +++ b/arch/arm/plat-omap/include/mach/irqs.h
>>> @@ -483,6 +483,7 @@
>>>  #ifndef __ASSEMBLY__
>>>  extern void omap_init_irq(void);
>>>  extern int omap_irq_pending(void);
>>> +extern void omap_ack_irq(unsigned int irq);
>>>  void omap3_intc_save_context(void);
>>>  void omap3_intc_restore_context(void);
>>>  #endif
>>> -- 
>>> 1.5.4.3
>>>
>>> --
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