IRQ4 - Serial Port Interrupt not invoked.
I am in process of writing a serial port driver on x86 on linux.
For some reason whenever i send some data to serial port
my IRQ4 interrupt handler is not being invoked.
1) I used register_irq(..) , register my interrupt handler , which
2) On opening /proc/interupt file i see IRQ 4 registered by my driver ,though there is not even a single hit.
3) I have set IER(Interrupt Enable Register) low four bits to 1 to enable all serial port interrupts.