Re: [PATCH] powerpc/smp: Do not disable IPI interrupts during suspend

[Kumar Gala <galak@kernel.crashing.org>]

On Aug 10, 2012, at 7:40 AM, Kumar Gala wrote:

> 
> On Aug 2, 2012, at 5:04 AM, Zhao Chenhui wrote:
> 
>> On Sat, Jul 28, 2012 at 08:20:31AM +1000, Benjamin Herrenschmidt wrote:
>>> On Fri, 2012-07-27 at 16:58 -0500, Kumar Gala wrote:
>>>> On Jul 20, 2012, at 7:47 AM, Zhao Chenhui wrote:
>>>> 
>>>>> During suspend, all interrupts including IPI will be disabled. In this case,
>>>>> the suspend process will hang in SMP. To prevent this, pass the flag
>>>>> IRQF_NO_SUSPEND when requesting IPI irq.
>>>>> 
>>>>> Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
>>>>> Signed-off-by: Li Yang <leoli@freescale.com>
>>>>> ---
>>>>> arch/powerpc/kernel/smp.c |    2 +-
>>>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>> 
>>>> BenH,
>>>> 
>>>> Can you ack?
>>> 
>>> No I'll merge it but not until it's been in next for a bit unless you
>>> have some strong emergency there, it's on my mental list of things to
>>> shovel into next after rc1.
>>> 
>>> Curiosity: didn't we use to disable all non-boot CPUs on suspend ?
>>> 
>>> Cheers,
>>> Ben.
>> 
>> Yes, we disabled all non-boot CPUs on suspend by calling disable_nonboot_cpus().
>> The disable_nonboot_cpus() needs IPIs to work. But prior to
>> calling disable_nonboot_cpus(), the IPIs are disabled in dpm_suspend_noirq().
>> 
>> -Chenhui
> 
> Benh, Ack?

Ben?

- k