Link Status Change(LSC) interrupt and packet receiving interrupt are all
enabled in l3fwd-power APP. Because of UIO only support one interrupt, so these
two kinds of interrupt need to share one, and the receiving interrupt have the
higher priority, so can’t get the right link status.

Implication:
When insmod igb_uio and running l3fwd-power APP, link status getting doesn’t
work properly.

Resolution/Workaround:
Use vfio-pci when LSC and packet receiving interrupt enabled.

Affected Environment/Platform:
ALL.

Driver/Module:
igb_uio module.