Not getting interrupts from PCI express slot

[Hans Petter Selasky]

On Wednesday 04 August 2010 23:24:12 Neel Natu wrote:
> Hi,
> 
> On Wed, Aug 4, 2010 at 12:29 PM, Hans Petter Selasky <hselasky at c2i.net> 
wrote:
> > On Wednesday 04 August 2010 21:13:55 Neel Natu wrote:
> >> Hi,
> >> 
> >> On Wed, Aug 4, 2010 at 10:18 AM, Hans Petter Selasky <hselasky at c2i.net>
> > 
> > wrote:
> >> > Hi,
> >> > 
> >> > I'm not getting any interrupts from a PCI express slot. When I insert
> >> > a device, no attach event is generated. If the device is present
> >> > during boot the device is fully detected, but still no IRQ's. Is
> >> > there anything I can do or test?
> >> 
> >> Is the driver using legacy INT-A style interrupt or MSI/MSI-X?
> > 
> > I don't know. How can I find out. It is a PCI driver like EHCI.
> 
> I looked at the ehci_pci.c driver and it looks like it only requests
> legacy interrupt. It may be that the legacy interrupt routing is
> screwed up by the BIOS.
> 

Hi,

> You can try a few things to narrow this down a bit:
> 
> % devinfo -ru: this will tell you which irq is being assigned to the ehci
> device
> 

devinfo -ru | grep -Ei "irq|port|xhci"
    16 (xhci0)
I/O ports:
    0xf6000000-0xf6001fff (xhci0)
ACPI I/O ports:


> % vmstat -i: this will tell you the number of interrupts received on
> that irq. It would be especially telling if you saw any stray
> interrupts as it may indicate bad interrupt routing.
> 

vmstat -i

irq16: xhci0                     5538390        957


Thanks for your reply. I'm now getting interrupts like other PCI devices. The 
only problem left is that my XHCI PCI express device does not generate an 
attach event when inserted. It is only detected if I boot with the device 
plugged in. Is it so to understand that PCI express system is not supported? 
How much effort would be required to add support for this?


--HPS