Re: [PATCH] genirq: Avoid NULL OOPS in irq handling

["\"陈华才\"" <chenhc@lemote.com>]

I use a Loongson-3(MIPS-series CPU) machine, there is a serial port
integrated in the CPU (but it iss buggy), and it use handle_percpu_irq()
as the irq handler. Maybe I should move the checking into
handle_percpu_irq()?

Huacai

> On Sat, 28 Sep 2013, Huacai Chen wrote:
>
>> Some devices (e.g. serial port) setup irq handler at dev open and free
>> it at dev close. So, sometimes there is no irqaction for a specific
>> irq. But some buggy devices may send irqs at any time. This patch avoid
>> the NULL OOPS when irqaction isn't registered.
>
> All callers except the real per cpu interrupts are checking whether
> there is a valid action before calling. And serial ports are not
> routed to real per cpu interrupts. Can you provide more detailed
> information about the problem you are trying to solve please?
>
> Thanks,
>
> 	tglx
>
>> Signed-off-by: Huacai Chen <chenhc@lemote.com>
>> ---
>>  kernel/irq/handle.c |    4 ++++
>>  1 files changed, 4 insertions(+), 0 deletions(-)
>>
>> diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
>> index 131ca17..1c78e69 100644
>> --- a/kernel/irq/handle.c
>> +++ b/kernel/irq/handle.c
>> @@ -135,6 +135,9 @@ handle_irq_event_percpu(struct irq_desc *desc,
>> struct irqaction *action)
>>  	irqreturn_t retval = IRQ_NONE;
>>  	unsigned int flags = 0, irq = desc->irq_data.irq;
>>
>> +	if (!action)
>> +		goto out;
>> +
>>  	do {
>>  		irqreturn_t res;
>>
>> @@ -174,6 +177,7 @@ handle_irq_event_percpu(struct irq_desc *desc,
>> struct irqaction *action)
>>
>>  	add_interrupt_randomness(irq, flags);
>>
>> +out:
>>  	if (!noirqdebug)
>>  		note_interrupt(irq, desc, retval);
>>  	return retval;
>> --
>> 1.7.7.3
>>
>>
>