Too Many Interrupts on the Parallel port

Hi all,

Success!!!

Thanks to Dave, my parport is now handling interrupts. But I do have
another slight problem. When the encoder moves too quickly, my computer
gets too many interrupts and it can't handle them. It freezes and never
recovers...resulting in a reboot :(

How do the interrupts work? Are they stored in a queue as they occur?
Could the queue be getting overfilled?

Could the amount of time needed to run throught the interrupt handler
function affect the freezing? My interrupt handler function simply
increments a counter and prints it's value to the kernel log. The printing
may be taking too long.

Is there a way to tell the driver to only handle interrupts if they occur
at a certain interval? Thus, if they are happening too rapidly, I could
just ignore a few of them.

Tim

On Wed, 17 Jul 2002, David Schleef wrote:

> On Tue, Jul 16, 2002 at 06:29:00PM -0700, Tim Beamish wrote:
> > I'm trying to cause an interrupt on the parallel port. I have a two
> > channel encoder and I've attached one channel to pin 10 of the parallel
> > port. I think this is the interrupt pin. I'm using RTLinux and I've loaded
> > the comedi_parport driver into the kernel. I've configured the
> > comedi_parport driver with the following line:
> >
> > /usr/sbin/comedi_config /dev/comedi1 comedi_parport 0x0378,3
> >
> > I picked IRQ 3 because it was empty.
>
> You don't get to chose the IRQ.  PC Parallel ports are usually on
> IRQ 7.
>
>
>
> dave...
>

Received on 2002-07-18Z17:33:29