On 27/06/15 04:52, Hanjun Guo wrote:
> On 06/24/2015 01:38 AM, Lorenzo Pieralisi wrote:
>> On Tue, Jun 23, 2015 at 04:11:38PM +0100, Hanjun Guo wrote:
>>
>> [...]
>>
>>>>> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
>>>>> index 8fc67bc..d1b2131 100644
>>>>> --- a/drivers/irqchip/irq-gic.c
>>>>> +++ b/drivers/irqchip/irq-gic.c
>>>>> @@ -851,15 +851,22 @@ static struct notifier_block gic_cpu_notifier = {
>>>>> static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
>>>>> unsigned int nr_irqs, void *arg)
>>>>> {
>>>>> - int i, ret;
>>>>> + int i;
>>>>> irq_hw_number_t hwirq;
>>>>> - unsigned int type = IRQ_TYPE_NONE;
>>>>> - struct of_phandle_args *irq_data = arg;
>>>>>
>>>>> - ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
>>>>> - irq_data->args_count, &hwirq, &type);
>>>>> - if (ret)
>>>>> - return ret;
>>>>> + if (domain->of_node) { /* DT case */
>>>>> + int ret;
>>>>> + unsigned int type = IRQ_TYPE_NONE;
>>>>> + struct of_phandle_args *irq_data = arg;
>>>>> +
>>>>> + ret = gic_irq_domain_xlate(domain, irq_data->np,
>>>>> + irq_data->args,
>>>>> + irq_data->args_count, &hwirq, &type);
>>>>> + if (ret)
>>>>> + return ret;
>>>>> + } else { /* ACPI case */
>>>>> + hwirq = (irq_hw_number_t)*(u32 *)arg;
>>>>> + }
>>>>
>>>> If domain->of_node is NULL and system booted with DT the code above
>>>> does not fail (and if it fails almost certainly that won't be graceful)
>>>> but it should.
>>>
>>> how about the following logic?
>>>
>>> if (!domain->of_node && acpi_disabled)
>>> return -ENODEV;
>>> else if (domain->of_node)
>>> dt related code;
>>> else
>>> ACPI related code;
>>
>> Code is not checking the node at present so:
>>
>> if (acpi_disabled)
>> dt code;
>> else
>> ACPI code;
>>
>> would do, but that's a nit.
>>
>>>>> for (i = 0; i < nr_irqs; i++)
>>>>> gic_irq_domain_map(domain, virq + i, hwirq + i);
>>>>> @@ -945,11 +952,11 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>>>>> gic_irqs = 1020;
>>>>> gic->gic_irqs = gic_irqs;
>>>>>
>>>>> - if (node) { /* DT case */
>>>>> + if (node || !acpi_disabled) { /* DT or ACPI case */
>>>>> gic->domain = irq_domain_add_linear(node, gic_irqs,
>>>>> &gic_irq_domain_hierarchy_ops,
>>>>> gic);
>>
>> I think this is a bit more worrying, I mean passing a NULL node pointer to
>> the irqdomain layer which basically means you are booting out of ACPI
>
> I'm little confused here, would you mind explaining more for your
> worrying? To me, node pointer is optional and it's ok for ACPI
> case.
>
>> (for you, if that's true for the irq_domain_add_linear implementation
>> that's another story), the node pointer should be optional but you
>> need feedback from IRQ layer maintainers here.
>
> Sure.
Frankly, I'd really like to see ACPI using the "node" parameter for
something useful. This would save having to cache pointers all over the
place, will make find_irq_host() work as expected... etc.
See the comment at the top of linux/irqdomain.h :
"... This code could thus be used on other architectures by replacing
those two by some sort of arch-specific void * "token" used to identify
interrupt controllers."
Maybe it is time to bite the bullet.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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