fasync (Async Notification)

[Vijay Nikam]

Hello All,

I have mpc8313erdb eval board and kernel 2..6.20 on it. I have written
GPIO driver and have enabled Async Notification (SIGIO)

In the driver I am generating interrupt whenever the status of GPIO
pin (GPIO 2) changes, this part is working correct (as soon as the
GPIO pin status changes the interrupt is generated).

Then I included Async Notification to notify the particluar user space
process (to the process which I want to) by using fasync method,
kill_fasync is called in Interrupt handler and also the kill_fasync
signals the particular process and the Signal handler executes and
says SIGIO is received.

But the problem is, if I change GPIO pin status twice then two
interrupts are generated but I get SIGIO Async Notification only once.
Whereras I am expecting that I should get twice SIGIO Async
Notification (Theory says the same).

Could anyone please let me what is the reason for this ? ? ?

Kindly please acknowledge ... thank you ...

Kind Regards,
Vijay Nikam