[rtl] Trying To Use "request_RTirq"

["Donald Radke" <radked@sympatico.ca>]

The code below is a modified version of "rt_process.c" found in the 2tasks
example.  I have the orginal 2task working but am curious about using an
interrupt instead.  From what I read about "request_RTirq" and "free_RTirq"
the below program should send a message to the FIFO everytime the timer
interrupt goes off.  Doesn't seem to do that though.  Nothing happens than
the linux task (app.c) ends.

I tried changing timer_irq value to 1 (keyboard) and I'll receive the data
message just after hitting the return key on the prompt line.  But no matter
how many times I hit the keyboard, nothing comes back from the RT-Task.

I understand "request_RTirq" to work as follows:

    request_RTirq ( monitor_irq, execute_some_func );

Whenever the monitor_irq (whichever one I want) goes off, perform the
function (ie execute_some_func).  I'm I wrong, or is there something else
that needs to be setup???

Donald Radke


/**********************************   Example Program
****************************************/
#define MODULE

#include <stdio.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/errno.h>

#include <linux/rt_sched.h>
#include <linux/rtf.h>
#include <asm/rt_irq.h>
#include "control.h"

RT_TASK       tasks[2];

static char   data[1024];

/*  Actual function to handle output  */
void irq_handler (  )
{
  int     i;

  for ( i = 0; i < 1024; i++ )
  {
    data[i] = 'R';
  }

  rtf_put ( fifo
          , &data
          , 1024
          );

  return;

}     /*  End Of irq_handler  */


int main_handler ( unsigned int fifo )
{
  struct    my_msg_struct     msg;
  int       err;
  int       timer_irq = 0;         /*  Set to timer interrupt  */

  while ((err = rtf_get(3, &msg, sizeof(msg))) == sizeof(msg))
  {
    switch (msg.command)
    {
      case START_TASK:
           request_RTirq ( timer_irq, &irq_handler );
           break;
      case STOP_TASK:
           free_RTirq ( timer_irq );
           break;
      default:
           return ( -EINVAL );
    }
  }
  if (err != 0)
  {
    return ( -EINVAL );
  }

  return ( 0 );
}

int init_module(void)
{
  rtf_create(1, 8000);
  rtf_create(3, 100);           /* input control channel */
  rtf_create_handler(3, &main_handler);

  return ( 0 );
}


void cleanup_module(void)
{
  rtf_destroy(1);
  rtf_destroy(3);
}

--- [rtl] ---
For more information on Real-Time Linux see:
http://www.rtlinux.org/