Subject: [PATCH v2 01/26] genirq: add irq_domain-aware core IRQ handler

From: [email-masked] (Stephen Boyd)
Date: Tue, 26 Aug 2014 12:05:51 -0700

On 08/26/14 11:46, Stephen Boyd wrote:
> On 08/26/14 11:07, Marc Zyngier wrote:
>> Digging into my email, one of the traces looked like this:
>>
>> stack backtrace:
>> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc1+ #135
>> Call trace:
>> [<ffffffc0000882cc>] dump_backtrace+0x0/0x12c
>> [<ffffffc000088408>] show_stack+0x10/0x1c
>> [<ffffffc0004ee5f0>] dump_stack+0x74/0xc4
>> [<ffffffc0000edfbc>] lockdep_rcu_suspicious+0xe8/0x124
>> [<ffffffc00010218c>] irq_find_mapping+0x16c/0x198
>> [<ffffffc00008130c>] gic_handle_irq+0x38/0xcc
>>
>> Most drivers call irq_find_mapping outside of irq_enter()/irq_exit(), as
>> this is in handle_IRQ().
>>
> Ah ok. This is the multi-irq handler case? Has this been broken since
> v3.2 at least for the gic users? Now that we call irq_enter()/irq_exit()
> a lot more code runs, including things like updating jiffies when
> interrupts arrive and invoking softirq? Do we only call irq_exit() on
> the IPI path otherwise?
>
> Are there any plans to send this back to stable trees? Not calling
> irq_enter()/irq_exit() when we get an interrupt seems like a big problem.
>

Hmm I see we still call handle_IRQ eventually. So it's not as bad as I
first thought.

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