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

- From: Kumar Gala \<hidden\>
- Date: 2012-08-10 12:41:16 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2012/08/3906528
- Thread: https://ratatoskr.run/linuxppc-dev/2012/07/3896451/t.md

```text

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:
>>>=20
>>>> 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.
>>>>=20
>>>> Signed-off-by: Zhao Chenhui <redacted>
>>>> Signed-off-by: Li Yang <redacted>
>>>> ---
>>>> arch/powerpc/kernel/smp.c |    2 +-
>>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>=20
>>> BenH,
>>>=20
>>> Can you ack?
>>=20
>> 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.
>>=20
>> Curiosity: didn't we use to disable all non-boot CPUs on suspend ?
>>=20
>> Cheers,
>> Ben.
>=20
> 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().
>=20
> -Chenhui

Benh, Ack?

- k=
```