When I set my GT to near-end PCS loopback, I see the bit error rate increasing. Is there an issue with my device?
Solution
This is a result of clock settings in the core. As a work-around, use PMA near-end loopback. Alternatively, you can change the Loopback mode to Near-End PMA and then change back to Near-End PCS. Reset Error count and note that no errors occur.