Why might Intel® Arria® 10 10GBASE-KR links get stuck during the Auto Negotiation stage with continuous IP resetting?

Due to a problem with the1G/10GbE and 10GBASE-KR PHY Intel® Arria® 10 FPGA IP in Intel® Quartus® Prime software version 19.1 and earlier, IP reset will potentially cause the link to get stuck during the Auto Negotiation stage. This is because there is an arbitration design glitch in the reconfiguration interface logic inside the 10GBASE-KR IP, which causes an incorrect register read-modify-write operation during link training process. The wrong register behavior together with PMA channel re-calibration will bring transmitter channel into power down stage resulting the link to stuck on AN state.

This problem is scheduled to be fixed in a future version of the Intel® Quartus® Prime software.