Q:Shared IRQ

Q:Shared IRQ

[David Stroupe]

I have written a driver for a pci board that uses interrupts.  I install 
the shared handler with a unique dev_id, or at least it should be unique 
as it is the address of my driver's internal data struct for that card. 
 I get not only my interrupts, but also the interrupts of the shared 
device, namely the network card.  Is this what I should expect?  If I 
get a notification for the network card, why is the dev_id the same as 
what I passed?  If I didn't have an interrupt pending bit on my 
hardware, how would I distinguish between the interrupts?

TIA

-- 
Best regards,
David Stroupe
Keyed-Up Software 

Re: Q:Shared IRQ

[Alan Cox]

>  I get not only my interrupts, but also the interrupts of the shared 
> device, namely the network card.  Is this what I should expect?  If I 

Yes.

> get a notification for the network card, why is the dev_id the same as 
> what I passed?  If I didn't have an interrupt pending bit on my 
> hardware, how would I distinguish between the interrupts?

If you don't have an interrupt pending bit you are probably completely screwed.
PCI assumes you can tell if you caused the interrupt or you can service events
even if not needed (which basically comes down to the same thing).

Only your driver knows if you are a possible IRQ cause, its up to you to
handle it