Re: [Xenomai-help] IRQ reservation and config

[Philippe Gerum <rpm@xenomai.org>]

Mike McTernan wrote:
>> Mike McTernan wrote:
>>> Hi,
>>>
>>> Right - I want the interrupt to be handled in realtime.
>>>
>>> Is there a way to configure the interrupt as level sensitive under
>>> Xenomai?  I can't see how to do it, hence the thought of using
>>> request_irq(), which can do that.
>>>
>> rtdm_irq_request() assumes that the platform-dependent code did set
> the
>> correct IRQ type/sense already.
> 
> Cool.  So I think you are saying it is valid to first request_irq() to
> setup and config the interrupt, then hook it with rtdm_irq_request() for
> the realtime handler afterwards. 
>

Yes; the IRQ could even be freed right away, since you only want request_irq()
to set the IRQ sense, and free_irq() won't undo anything.

> I was unsure about mixing calls to the rtdm with the normal APIs, but it
> sounds like in this case it is not a problem and the recommended method.
> 

I would say that the recommended method is rather to have the BSP code do
whatever is needed to set the damn thing properly, but if it does not, plan B
may be to count on request_irq() to call the set_type() callback of the related
interrupt chip for the IRQ in question. That should work (Famous Last Words).

> Many Thanks,
> 
> Mike
> 
> 


-- 
Philippe.