IRQ numbering (was: Better timer and RTC handling for 8641HPCN.)

[Kumar Gala]

>>>>> Please use 80.
>>>>> We reserve the first 16 ints for legacy 8259 interrupts. And we
>>>>> want the
>>>>> virq is the same value to hw-irq.
>>>>
>>>> Why?
>>>
>>> If the virq equals hw-irq, it's clear and simple to user.
>>
>> I don't think that's a good reason to over allocate.
>>
>> There's a reason we have virtual IRQs now.  Its specifically to deal
>> with issues like the 16 interrupts for 8259 and not have to do games
>> to offset IRQs.
>>
>> If we needed create some debugfs or sysfs info that translates VIRQ
>> to HW irq
>>
>
> I know that's the advantage of virtual IRQs. But in this platform, we
> want to fix up the virq to hwirq and let users know which irq is  
> coming
> from which devices.

But how do I know IRQ 42 is really 26 for the MPIC.  What are you  
users doing that they can't handle the virtual irq concept?

It was pointed out, that you are coupling the IRQ # in the .dts with  
the kernel virtual number which is a bad idea.  In theory the device- 
tree description shouldn't be coupled this tightly to the kernel.

I think the Freescale reference boards should strive to show people  
how to do things properly since people tend to copy this code and use  
it as a starting point.  I doubt most 86xx designs are really going  
to have an 8259 controller on them and thus making things focus  
around it seems silly.

- k