From: paul DOT crone AT thomson-csf DOT no
Message-Id: <200101160749.IAA03089@alcatel.no>
To: djgpp AT delorie DOT com
Subject: Re[2]: Problem using timer and irq routines from Allegro
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Date: Tue, 16 Jan 2001 08:42:47 +0100
Reply-To: djgpp AT delorie DOT com

> 
> paul DOT crone AT thomson-csf DOT no wrote:
> > I have a problem that I've been trying to resolve for some time.  This
is a 
> > test harness program to test a timer routine using the Allegro timer.c,
> > irq.c and irqwrap.S files.  I want to use them in my program.
> 
> > The program runs and apparently installs the timer and irq's.  My
> > problem is that I don't get any interrupt 'timerRCU' callbacks and
> > so the printf statement never prints.
> 
> Please be aware that you shouldn't be calling any other functions from
> an interrupt handler. Certainly not a complicated one like printf().

I understand your point.  The interrupt routine does nothing but increment a
counter.  The
printf statement is in the main loop.

> 
> I didn't really look at all the code, but there's another possible
> problem that comes to mind. You seem to be talking about *two* timer
> packages (yours, and the one from allegro) being active at the same
> time. Such a setup generally won't work, unless you make sure you use
> two independent timer tick IRQ sources, and properly chain interrupt
> handlers, where appropriate.

The code seeks to reprogram the timer chip.  The reference to Allegro was
merely to state
that my code is a copy of the Allegro source code.  Allegro is not otherwise
being used
here.  I think that you are right when you say that the interrupt chaining
is incorrect. 
That is my problem.

Thanks for your suggestions.

Paul
> -- 
> Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
> Even if all the snow were burnt, ashes would remain.
>