According to PCIe spec, when a RootPort sends a memory request during power management D-state, the EndPoint should return a completion without data. Whilst the Intel® Arria® 10 PCIe* Hard IP is able to receive the completion without data, the Avalon®-MM TXS bridge always expects completion with data. The Avalon-MM TXS bridge will drop any completion without data after a memory read request is sent from the Avalon-MM TXS interface.
When user application uses the Intel® Arria® 10 Avalon®-MM Interface for PCIe* in Root Port mode, the connected endpoint will always receive completion with data after the endpoint sends memory read request.
According to PCIe* spec, when a RootPort is in any power management D-state, it should send completion without data after receiving a memory read request. the Intel® Arria® 10 Avalon®-MM Interface for PCIe* in Root Port mode violates this rule.
No workaround for this problem exists. The user application and software should be aware of the limitation and ensure that this scenario doesn't happen.
When using the Intel® Arria® 10 Avalon®-MM Interface for PCIe* in Root Port mode, be aware that the endpoint will always receive completion with data from an Intel® Arria® 10 Avalon®-MM Interface for PCIe* in Root Port mode.
This problem will not be fixed in a future release of the Intel® Quartus® Prime software as the Intel® Arria® 10 Hard IP has limited support for the power management D-state.