Hi Jon,
On 11/10/2015 05:58 PM, Jon Hunter wrote:
> Hi Thomas,
>
> On 10/11/15 15:26, Thomas Gleixner wrote:
>> Jon,
>>
>> On Tue, 10 Nov 2015, Jon Hunter wrote:
>>> void (*irq_suspend)(struct irq_data *data);
>>> void (*irq_resume)(struct irq_data *data);
>>> + int (*irq_runtime_suspend)(struct irq_data *data);
>>> + int (*irq_runtime_resume)(struct irq_data *data);
>>> void (*irq_pm_shutdown)(struct irq_data *data);
>>
>> So this is the second patch within a few days which adds that just
>> with different names:
>>
>> http://lkml.kernel.org/r/1446668160-17522-2-git-send-email-soren.brinkm...@xilinx.com
>>
>> Can you folks please tell me which of the names is the correct one?
>
> Sorry. I was unaware of that patch.
>
>>> +/* Inline functions for support of irq chips that require runtime pm */
>>> +static inline int chip_runtime_resume(struct irq_desc *desc)
>>> +{
>>> + if (!desc->irq_data.chip->irq_runtime_resume)
>>> + return 0;
>>> +
>>> + return desc->irq_data.chip->irq_runtime_resume(&desc->irq_data);
>>> +}
>>> +
>>> +static inline int chip_runtime_suspend(struct irq_desc *desc)
>>> +{
>>> + if (!desc->irq_data.chip->irq_runtime_suspend)
>>> + return 0;
>>> +
>>> + return desc->irq_data.chip->irq_runtime_suspend(&desc->irq_data);
>>
>> We really don't need a return value for that one.
>
> Ok.
>
>>> +}
>>> +
>>> #define _IRQ_DESC_CHECK (1 << 0)
>>> #define _IRQ_DESC_PERCPU (1 << 1)
>>>
>>> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
>>> index 0eebaeef317b..66e33df73140 100644
>>> --- a/kernel/irq/manage.c
>>> +++ b/kernel/irq/manage.c
>>> @@ -1116,6 +1116,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc,
>>> struct irqaction *new)
>>> if (!try_module_get(desc->owner))
>>> return -ENODEV;
>>>
>>> + ret = chip_runtime_resume(desc);
>>> + if (ret < 0)
>>> + return ret;
>>
>> Leaks module ref count.
>
> Ok.
>
>>> +
>>> new->irq = irq;
>>>
>>> /*
>>> @@ -1393,6 +1397,7 @@ out_thread:
>>> put_task_struct(t);
>>> }
>>> out_mput:
>>> + chip_runtime_suspend(desc);
>>> module_put(desc->owner);
>>> return ret;
>>> }
>>> @@ -1506,6 +1511,7 @@ static struct irqaction *__free_irq(unsigned int irq,
>>> void *dev_id)
>>> }
>>> }
>>>
>>> + chip_runtime_suspend(desc);
>>> module_put(desc->owner);
>>> kfree(action->secondary);
>>> return action;
>>> @@ -1792,6 +1798,7 @@ static struct irqaction *__free_percpu_irq(unsigned
>>> int irq, void __percpu *dev_
>>>
>>> unregister_handler_proc(irq, action);
>>>
>>> + chip_runtime_suspend(desc);
>>
>> Where is the corresponding call in request_percpu_irq() ?
>
> I was trying to simplify matters by placing the resume call in
> __setup_irq() as opposed to requested_threaded_irq(). However, the would
> mean the resume is inside the bus_lock and may be I should not assume
> that I can sleep here.
>
>> Can you folks please agree on something which is correct and complete?
>
> Soren I am happy to defer to your patch and drop this. My only comment
> would be what about the request_percpu_irq() path in your patch?
>
I have the same comment here as I asked Soren:
1) There are no restrictions to call irq set_irq_type() whenever,
as result HW can be accessed before request_x_irq()/__setup_irq().
And this is used quite widely now :(
For example, during OF boot:
[a] irq_create_of_mapping()
- irq_create_fwspec_mapping()
- irq_set_irq_type()
or
irq_set_irq_type(irq, IRQ_TYPE_LEVEL_HIGH);
irq_set_chained_handler(irq, mx31ads_expio_irq_handler);
or
irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
(there are ~200 occurrences of irq set_irq_type in Kernel)
2) if i'm not wrong, the same is valid for irq_set_irq_wake() and
irq_set_affinity()
I'm not saying all these code is correct, but that what's now in kernel :(
I've tried to test Soren's patch with omap-gpio and immediately hit case [a]
:.(
--
regards,
-grygorii
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