How to find irq number associated with PCI interrupt

P.S.R.K.S.PRASAD · 10-26-2006, 06:53 AM

Hi,
I am a beginner in developing Linux device driver.I want to install interrupt handler using request_irq() call.The problem is the first argument.It is irq number associated with PCI interrupt line.I am getting this number with pci_read_config_byte(dev,PCI_INTERRUPT_LINE,&irqno).If I am passing this irqno to request_irq() call it is not catching the interrupt.Is the above method of finding irqno correct?If not please suggest the correct method.
Thank you.

Regards,
P.S.R.K.S.PRASAD

manwichmakesameal · 10-27-2006, 12:24 PM

So let me get this straight, you are trying to get an irqno and then register it? I just got this out of a book, so take it as you will.

Code:

static irqreturn_t intr_handler(int irq, void *dev_id, struct pt_regs *regs)

sudhaanil · 11-07-2006, 05:22 PM

Hi Prasad,

What is the request_irq() returning ?

Also, post the dmesg after you run your driver module.

Thanks,
Anil.

P.S.R.K.S.PRASAD · 11-08-2006, 11:33 PM

Hi,
I don't remember the prototype of request_irq.You can find it in the book Linux Device Drivers.The soft copy is available for free.For printed edition the publisher is O'REILLY publishing company.

Bye,
P.S.R.K.S.PRASAD