Re: [Xenomai-help] IRQ1 forwarded to Linux?

[Philippe Gerum <rpm@xenomai.org>]

Guillaume Boutillier wrote:
>>Guillaume Boutillier wrote:
>>
>>>Hello,
>>>
>>>
>>>
>>>>>ROSSIER Daniel wrote:
>>>>>
>>>>>
>>>>>>Hello,
>>>>>>
>>>>>>
>>>>>>
>>>>>>We have a small Xeno application which implements an interrupt service 
>>>>>>(ISR) on IRQ 1 (keyboard) – quite stupid, but
>>>>>>
>>>>>
>>>>>Sorry,
>>>>>
>>>>>- $ cat /proc/ipipe/Linux
>>>>>+ $ cat /proc/ipipe/Xenomai
>>>
>>>
>>>I checked when I run my application... 
>>>But I couldn't understand the meaning of the different flags : accepted,
>>>passed and grabbed?! 
>>>
>>
>>What about posting the output to this list? Maybe someone could help.
>>
> 
> 
> Sorry I forgot the results...
> 
> when I run the application with RT_INTR_PROPAGATE :
> 
> $ cat /proc/ipipe/Xenomai
> Priority=200, Id=0x58454e4f
> irq0-1: grabbed
> irq2-31: passed
> irq32-33: passed, virtual
> irq34: grabbed, virtual
> 
> $ cat /proc/ipipe/Linux
> Priority=100, Id=0x00000000
> irq0-15: accepted
> irq32-33: grabbed, virtual
> irq34: passed, virtual
> 
> 
> when I run the application with RT_INTR_HANDLED
> 
> $ cat /proc/ipipe/Xenomai
> Priority=200, Id=0x58454e4f
> irq0-1: grabbed
> irq2-31: passed
> irq32-33: passed, virtual
> irq34: grabbed, virtual
> 
> $ cat /proc/ipipe/Linux
> Priority=100, Id=0x00000000
> irq0-15: accepted
> irq32-33: grabbed, virtual
> irq34: passed, virtual
> 

"grabbed" means that the domain intercepts the IRQ, and will let its own 
handler decide whether the interrupt needs to be propagated down the 
pipeline or not (a manual call to ipipe_propagate_irq will be needed if 
so). IOW, Adeos stops scanning the pipeline chain upon IRQ receipt after 
this domain's stage; it would do that otherwise to discover new 
(lower-priority) domains wanting to handle this IRQ too.

"accepted" means that Adeos will let the domain process the IRQ, and 
keep on searching for (lower-priority) domains wanting to handle it too.

"passed" means that Adeos will not ask the domain to handle the IRQ, but 
will try to pass it to the next domain down the pipeline.

"discarded" means to make as if the IRQ never happened starting from the 
current one, i.e. neither the current nor the lower-priority domain will 
ever know about it.

Regarding the specific case of the keyboard input still working despite 
the kbd interrupts can't flow, it's likely due to the fact that the 
input sub-system (i8042 serio driver) also polls the attached devices 
according to a HZ/20 period, in addition to handling the interrupts.

-- 

Philippe.