Re: [Xenomai-core] [Combo-PATCH] Shared interrupts (final)

[Philippe Gerum <rpm@xenomai.org>]

Jan Kiszka wrote:
> Philippe Gerum wrote:
> 
>>Anders Blomdell wrote:
>>
>>
>>>My distinct feeling is that the return value should be a scalar and
>>>not a set!
>>>
>>
>>To sum up, the valid return values are HANDLED, HANDLED | ENABLE (*),
>>HANDLED | CHAINED and CHAINED. It's currently a set because I once
>>thought that the "handled" indication (or lack of) could be a valuable
>>information to gather at nucleus level to detect unhandled RT
>>interrupts. Fact is that we currently don't use this information,
> 
> 
> But it is required for the edge-triggered case to detect when the IRQ
> line was at least shortly released. I guess Dmitry introduced that NOINT
> just because HANDLED equals 0 so far. As I would say HANDLED == !NOINT,
> we could avoid this new flag by just making HANDLED non-zero.
> 

Yes, we could. HANDLED is currently zero only because the nucleus does not care of 
the !handled case, yet.

> 
>>though. IOW, we could indeed define some enum and have a scalar there
>>instead of a set; or we could just leave this as a set, but whine when
>>detecting the invalid ENABLE | CHAINED combination.
> 
> 
> In combination with the change above and some doc improvement ("valid
> combinations are: ..."), I could also live with keeping the flags. The
> advantage were that we wouldn't break existing applications.
> 
> 
>>(*) because the handler does not necessary know how to ->end() the
>>current IRQ at IC level, but Xenomai always does.
>>
> 
> 
> Jan
> 


-- 

Philippe.