question in request_threaded_irq

[Haojian Zhuang]

On Mon, Aug 15, 2011 at 7:03 PM, radhika bhaskaran <radhibhas at gmail.com>wrote:

> Hi javier,
>
> Thanks for the help.
>
> I have tried the suggestion made by you. But unfortunately it did not work.
>
> For my debugging purpose i tried to register two isr's on the same number
> IRQ no in  the same driver. But the isr which is registerd first is being
> hit.
>
> The other isr funciton which is registered after the first isr is never
> executed.
>
> Any more suggestions?
>
>
IRQ_SHARED flag could work if IRQ_ONESHOT isn't enabled.

In your request_threaded_irq(), you assigned thread_func() and NULL for
handler_func(). It means that IRQ_ONESHOT is enabled. You either registered
it to handler_func(), or abandon irq handler sharing between multiple
drivers.


>
> On Sun, Aug 14, 2011 at 6:31 AM, Javier Martinez Canillas <
> martinez.javier at gmail.com> wrote:
>
>> On Sat, Aug 13, 2011 at 9:25 PM, radhika bhaskaran <radhibhas at gmail.com>
>> wrote:
>> > Hi,
>> > I have a question with respect to request_threaded_irq.
>> > Assume that one driver has registered and ISR on some particular irq
>> number.
>> > Can i use the same irq number and register and isr in another driver.
>> > Because that is my requirement.
>> > when i try to do that is an error message with an error no as -19.
>> >  err = request_threaded_irq(pdata->irq , NULL, testing_fucntion,
>> >                             IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
>> > "testing_function", dev);
>> > Can some one please help me whether it is possible.
>> > Regards,
>> > RB
>>
>> You have to use the IRQF_SHARED flag that specifies the IRQ will be
>> shared for two devices:
>>
>> err = request_threaded_irq(pdata->irq , NULL, testing_fucntion,
>> IRQF_SHARED |
>>                                       IRQF_TRIGGER_FALLING |
>> IRQF_TRIGGER_RISING,
>>                                      "testing_function", dev);
>>
>> Have in mind that the kernel invokes every handler registered for that
>> IRQ every time an interrupt occurs on that line. So you have to check
>> in each ISR if the hardware raised the interrupt.
>>
>> Hope it helps,
>>
>> --
>> Javier Martínez Canillas
>> (+34) 682 39 81 69
>> Barcelona, Spain
>>
>
>
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