I was showing my engineering friend the wonders of rtlinux,
setting it up on his machine, and monitoring the parallel port
with his scope, when we came across a couple of examples that
didn't work, namely:
/usr/rtlinux-3.0/examples/v1api/parallel/rtc_toggle.c
/usr/rtlinux-3.0/examples/v1api/parallel/rtc_toggle_fifo.c
We found their interrupts only went off once, then stopped.
For fun we debugged them, and found the problem was just
the interrupt handler; wasn't calling
I'm guessing these programs were written to use the older
API which automatically re-enabled the irqs, but when ported
to the new API, they forgot to add the necessary irq enable.
To make the examples work, just add the rtl_hard_enable_irq(8)
call above the 'break' statement for 'case 0' in handler(), eg:
_________________________________________________________________________
unsigned int handler(unsigned int irq_number, struct pt_regs *p) {
/* Do not rt_task_wait() in a handler */
switch(shutdown_flag){
case 0:
outb(output, LPT_PORT);
/* I'm too lazy to figure out which pin is which
so just toggle all of them */
output = ~output;
(void) CMOS_READ(RTC_REG_C); /* clear IRQ */
rtf_put(0, &samp, sizeof(samp));
samp++;
rtl_hard_enable_irq(8); // <--- ADD THIS LINE
break;
_________________________________________________________________________
Once that's added, both examples will work correctly; the scope puts
out a nice square wave, and the fifo starts generating data you can
view with 'od -x /dev/rtf0'.
Other examples should likely be checked for this problem.
HTH..
ps. I really dig rtl. I've already got an RTL interrupt driver going
for a popular 'Kuper Controls' RTMC48 stepper motor card used in the
motion picture effects industry. I'm porting my optical printer
motion control software from DOS to RTL, and it's been a breeze
so far.. great work.
--
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|o,o|
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Greg Ercolano UNIX NightOwl / Systems Programmer & Admin
[EMAIL PROTECTED] http://3dsite.com/people/erco/
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