Use the following reset sequence when using near end PMA loopback for high line rates >= 25G
1. Have GTY in non loopback mode (LOOOPBACK=3'b000), reset using GTRXRESET.
2. Put GTY in near end PMA looopback (LOOPBACK=3'b010).
3. Reset RX using RXPMARESET.
If line rate is < 25G, the GTY can be put into near end PMA loopback reset normally without issue and the above sequence is not needed.