When using the second GTX in a tile on Virtex-5 FXT, the value programmed via the DRP for the PMA_CDR_SCAN attribute is not optimal.
Problems have not been observed, but this could reduce the reliability of the data sampling on receiver by an indeterminate amount. This only effects the second GTX in a tile on Virtex-5 FXT devices. This does not effect the first GTX or other devices.
This issue is scheduled to be fixed in the next version of the CPRI core due out in 11.2.