Hi, all

I want to add a pci device just like pci-serial to QEMU, there are some qeustion while add a IRQ.

 

In the init() function,

pci->dev.config[PCI_INTERRUPT_PIN] = 0x01;

s->irq = pci->dev.irq[0];

 

In the write() function

qemu_irq_raise(s->irq);

if (val & 0xff) == 0x99)

qemu_irq_low(s->irq);

 

What i want to do is generate an interrupt when write to io port, and then the interrupt routine in Linux will response this IRQ. And write 0x99 , then the qemu_irq_low(s->irq); will be called. However, the interrupt routine is called all the time.

 

What's the problem? What's the correct routine to add an interrupt?

 

Thanks.