Re: shared interrupts

On Tuesday 24 January 2006 09:08 pm, Calin A. Culianu wrote:
>
> So basically, when a board asserts an interrupt, it will keep the line
> high (since PCI interrupts are level-triggered) until the board is
> satisfied (most probably by the ISR for the board setting some bits in a
> register to acknowledge the interrupt)? 

Yes, linux for example just runs all the interrupt handlers for the 
asserted irq line in a loop until something useful happens and the 
interrupt stops being asserted.

> So  you are basically describing it as: A pended (to Linux) interrupt
> will be masked out until it is serviced by linux (otherwise you get
> infinite calls to the rt handler)... thus priority inverting the RT ISR
> you actually want to run...?

Yes.

-- 
Frank