ISR has not been called , while PCIe device certainly raised it

NTDEV
1

Hi guys,
My PCIe device is working well on one host.
On another host , the device is working but the ISR is not called. Note: driver, sw & device are same , just different motherboard.
From signal tap it is clear that #INTR is up and remains up because driver is not resets the line.
What could be reasons that INTR is not coming to the driver ?
Do you have idea ?

2

Note: we use legacy INTx mode PCI Express Gen2.
Motherboard : X10SRA/X10SRA-F , chipset C612 .

3

Is the IRQ (in device manager) same on both machines?
Can some other device share this INTx?
– pa

4

Pavel thank you for response,

  • Different IRQs in different machines.
  • No other device shares the same IRQ, on this machine.
    BTW, I tried to disable the Interrupt Remapping in BIOS, but this leads to BSOD.
5

It may be a hardware or BIOS bug of the mobo. It happens sometimes. Sorry, cannot tell more from the available data.
While you’re waiting for more useful replies, try to run your driver with verifier…

– pa