Experimental Physics and
Industrial Control System

Bill Brown <[email protected]> · Fri, 29 Sep 2000 08:21:01 -0700

I'm working on the interupt service section of a driver for
a timer/counter IP (Greenspring IP-UnidigT).  Don't know that
we'll ever really use the IP - it was relatively cheap and simple
so it seemed like a good target for learning the pitfalls of
interrupts on IP's.

The problem is in figuring out which vector to use.

ipmIntConnect() for at least some carriers simply makes a call to
intConnect() which "just does it"; there is no checking that the
vector is not already in use.

devConnectInterupt checks that the vector is not assigned before
it calls intConnect() and returns a status which may indicates that the
vector requested is already in use.  In the case that the vector is
in use it seems like the IP driver could just try again with another
vector.

Is there any reason why ipmIntConnect() couldn't call devConnectInterupt()
instead, thereby simplifying debugging and perhaps book keeping?

I also see that drvIpMv162.c doesn't seem to support this entry point.
Does this mean that IP-generated interrupts cannot be supported when
using the mv162 (or '172?) as a carrier?

I have the feeling that once again I can't find the trees 'cause the
forest is in the way.  Any help greatly appreciated!

-bill

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System