Re: Interrupt handlers in NetBSD 5.0

[David Laight <david%l8s.co.uk@localhost>]

On Tue, Jun 09, 2009 at 02:25:26PM +0200, Joerg Sonnenberger wrote:
> On Tue, Jun 09, 2009 at 01:56:29PM +0200, Hans Petter Selasky wrote:
> > Are you trying to explaing this is not possible?
> 
> The interrupt is still masked when the handle is called. So if you want
> to defer the actual work to a thread or so, you have to make sure that
> the hardware is quiet (e.g. acknowledge the interrupt).

You also need to delay (somehow!) long enough after writing the device
register for the IRQ to be de-asserted at the interrupt controller.
Given that writes may be buffered (posted) at all sorts of places
this can be difficult to guarantee.
Otherwise you get a 'splurious interrupt' message - especially
on Solaris.

        David

-- 
David Laight: david%l8s.co.uk@localhost