MPC885 interruptions : help !

[scarayol at assystembrime.com]

Hi all,

I wrote a module driver to manage interruptions. I have an interruption on
MPC885 IRQ7 activated by a push button that provides a negative pulse of
200 ns width.
When the device is open, i call request_irq() to install the interrupt
handler:

int ret = request_irq(SIU_IRQ7, fpgadriver_irq_save_handler, SA_INTERRUPT,
FPGA_ID, NULL);

void fpgadriver_irq_save_handler(int irq, void *dev_id, struct pt_regs
*regs)
{
  fpga_it_source=FPGA_IRQ_SAVE;
  printk( "fpgadriver: fpgadriver_irq_save_handler for device \n");
  /* Prepare a task */
  PREPARE_TQUEUE(&fpgadriver_bh_task, fpgadriver_bh_handler, dev_id);
  /* Add a task to the immediate bottom half and mark it for schedule */
  queue_task(&fpgadriver_bh_task, &tq_immediate);
   mark_bh(IMMEDIATE_BH);
}

my read() is like that :

static ssize_t fpgadriver_read(struct file *file, char *buf, size_t count,
loff_t *ppos)
{
  //mise a jour de l'indicateur d'etat d'endormissement
  wakeups++;
  interruptible_sleep_on(&readq);
  buf[0]=fpga_it_source;
  printk("fpgadriver_read  \n");
  return 0;
}

I have the wake_up_interruptible(&reaq) in fpgadriver_bh_handler(). My
problem is that fpgadriver_irq_save_handler() is never called as if there
is no interruption.
Is there something else to modify to validate the interruption ? Is
SIU_IRQ7 the right value for my interruption ? What have i to check ?

Thanks for your reply.

Sophie CARAYOL