Re: [Xenomai-help] RTDM driver structure - an update

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Bob Feretich wrote:
>   Comments inline..
> 
> On 8/10/2010 6:18 AM, Gilles Chanteperdrix wrote:
>> ...snipped...
>> The RTDM_IRQTYPE_EDGE is documented in RTDM API documentation: "Mark IRQ
>> as edge-triggered, relevant for correct handling of shared
>> edge-triggered IRQs. " Here:
>> http://www.xenomai.org/documentation/xenomai-2.5/html/api/group__rtdmirq.html
> The above quotation is the full extent of the documentation. The driver 
> authors (we) ask the question, "Should I include this flag when I call 
> rtdm_irq_request()?" The documentation leaves the answer ambiguous in 
> the case where the RTDM_IRQTYPE_SHARED flag is not coded.
> 
> It also creates confusion. We assume that RTDM_IRQTYPE_EDGE will cause 
> hardware to be configured similar to request_irq().We knows that the 
> specification of RTDM_IRQTYPE_EDGE is insufficient.  Normally we need to 
> specify which edge is to cause the interrupt. We question whether 
> specifying RTDM_IRQTYPE_EDGE will cause our ISR to be entered on both 
> rising and falling edges.

Yes, the doc is not perfect, but in this case, I find the sentence
unambiguous, this flag is only relevant for shared irqs. And Xenomai is
free software, it means that:
- in case of doubt you may have a look at the code;
- we accept documentation patches.

> 
> The essence of this e-mail discussion eventually needs to be added to 
> the rtdm_irq_request() documentation.

I agree that we should try and improve the documentation. But in the
rtdm_irq_request case, it is even the interface which we should improve
by adding bits for setting the hardware, and when we are done, the
documentation work will be much simpler.

-- 
					    Gilles.