How do external irq's get mapped?

[Andy Fleming]

On May 2, 2007, at 17:11, Charles Krinke wrote:

>> The new problem is that if I set the irq to 112, when it is
>> insmodded, I
>> get an error from open_pic.c of the form:
>>
>> Open_pic.c:720 invalid irq 112
>>
>> This seems to be coming from the macro at line 144 in open_pic.c
>>
>> #define check_arg_irq(irq) \
>>     if (irq < open_pic_irq_offset || irq >=
>> NumSources+open_pic_irq_offset \
>> 	|| ISR[irq - open_pic_irq_offset] == 0) { \
>>       printk("open_pic.c:%d: invalid irq %d\n", __LINE__, irq); \
>>       dump_stack(); }
>
>
> Any  chance you can identify:
>
> 1) Where this macro is being called from when it fails
>
> 2) Which of the 3 conditions above are actually true
>
> Andy
>
> Dear Andy:
>
> In our system, open_pic_irq_offset=80, numSources=60, *but* ISR[irq -
> open_pic_irq_offset]=NULL when irq 112 is enabled.
>
> It looks to me like each call to openpic_set_sources inits ISR[]
> elements according to the first two arguments. We have two calls to
> openpic_set_sources.
>
> Internal irqs 00..31, 1st openpic_set_sources(0, 32) -- ISR[0..32]
> External irqs 48..60, 2nd openpic_set_sources(48, 12) -- ISR[48..60]


Heh.  Whoops!  I didn't see the gap.  112-127 are, indeed, unmapped  
in this implementation.  Sorry about that.  You're going to want 80 
+48 = 128 for EXT0

>
> But ISR[112] is never initialized in the source base.
>
> I tried the cheap shot of adding a third openpic_set_sources(112, 12),
> but I suspect the real answer is a bit more complicated then that.


Yeah, that would set up interrupts from 192 to 203, which *also*  
don't exist.

Andy