PCI Express AER Driver calling NMI

[vipin240406]

I have developed a PCI-Express Device driver for a end point device. I
want to get support of AER in my driver. I have enabled AER by calling
pci_enable_pcie_error_reporting. I have checked device configuration
space AER is enabled there. I triggered UR error messages by probing a
non-existent device function.

But when I do this. NMI is called istead of AER handler.

So please reply for following queries :

1. Is this expected behaviour ?
2. If not, than please tell me what i am doing wrong ?
3. what steps I have to follow to get out of this ?

[vipin240406]

Ihave recieved following messeges when NMI was called

Uhhuh. NMI received for unknown reason 20 on CPU 0.
Do you have a strange power saving mode enabled?
Dazed and confused, but trying to continue

[vipin240406]

Need inputs/suggestions for an issue, I'm encountering related to PCIe Advanced error reporting

Enabling Advanced Error Reporting (AER) using pci_enable_pcie_error_reporting API.
Verified AER is enabled by looking into device configuration space.
Also enabled interrupt bits in

Device Control Register,

Unmask bits of

Uncorrectable Error Mask Register
Correctable Error Mask Register.

For testing the functionality of AER I am executing following test case :

Triggered an Unsupported Request error messages by probing a non-existent device function
(if a PCI Express device only has one function, then kernel reads the ClassID from the configuration space of the second function of the device treated as Unsupported Request).

Now the device sends an Unsupported Request error message to the root port and sets the bit in the uncorrectable error status register.

By executing the above steps, NMI is called instead of AER handler and below message is seen.

Uhhuh. NMI received for unknown reason 20 on CPU 0.
Do you have a strange power saving mode enabled?
Dazed and confused, but trying to continue

Look forward for reply and thanks in advance.

best regards
-vipin