[Asterisk-Users] Generic X100P's

[Peter Svensson]

On Tue, 12 Oct 2004, Steven Critchfield wrote:

> Funny since there is only 4 real IRQ lines on a PCI bus. They are A, B,
> C, and D. If you have more than 4 slots on a PCI bus, then you are most
> definately reusing a real IRQ wire. 
> 
> As for if PPC could handle it, I haven't seen any drivers. Could be me
> ignoring those threads.  

This is not correct. Each pci slot has four physical interrupt lines, A-D. 
The implementation is free to supply four separate interrupt lines to each 
card, i.e. the interupt lines are different for each slot on the bus.

On the other hand, most of the comments about the problems with interrupt 
sharing on the pci bus are not very informed either. The interrupt handles 
are normally very fast and the pci specification definitly allows for 
shared interrupts. I suspect either a hardware problem or that the dirvers 
are somehow incorrect. 

Does anyone have any hard numbers on the interrupt latencies tolerated by 
the digium cards? I would assume 100-200us to be acceptable. 

Peter