A problem about interrupt when booting a captured kernel

[Yang Yingliang]

On 2015/11/17 17:16, Marc Zyngier wrote:
> On Tue, 17 Nov 2015 11:48:07 +0800
> Yang Yingliang <yangyingliang at huawei.com> wrote:
>
>> Hi
>>
>> On 2015/11/17 3:26, Marc Zyngier wrote:
>>> On 13/11/15 10:09, Yang Yingliang wrote:
>>>> Hi, Marc
>>>>
>>>>
>>>>        The kexec will boot a captured kernel while the kernel panic. But
>>>> it boots failed if the kernel panic in handler function of PPI. The
>>>> reason is that the PPI has not been 'eoi', other interrupts can not be
>>>> handled when booting  the captured kernel.
>>>>
>>>>        The kexec will call irq_eoi to end the irqs that have
>>>> IRQD_IRQ_INPROGRESS flag. But PPIs don't have this flag, so it won't be
>>>> ended.
>>>>
>>>>       Three ways to solve this problem we can think :
>>>>       1. Is there a way to reset gic like its_reset ?
>>>>       2. Can we add some flag for calling irq_eoi ?
>>>>       3. Just 'eoi' all PPIs without checking flags in kexec.
>>>>
>>>>        Please give some advice.
>>>
>>> Good timing. Please see:
>>>
>>> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-November/385383.html
>>>
>>> and let me know if that fixes things for you.
>>
>> I tried patch #1, deactivating interrupt can not fix the problem. But
>> EOI the interrupt can.
>
> You have noticed that this patch is for ARM, not arm64, right?

Yes, I noticed.

>
>> I think the reason is GICC status is not cleared.
>> So if it means, in hardware, we should clear the GICC status while
>> deactivating the.
>
> Writing to the EOI register or writing to the ACTIVE register have the
> exact same result as far as kexec is concerned (unless your GIC is not
> compliant with the architecture - in which case I can't help you).
>
> Does applying the other patches help?

No, it doesn't help.

>
> Thanks,
>
> 	M.
>