In the Vivado 2015.4 DisplayPort v6.1 (Rev. 1) GUI, when I change the number of lanes from 4 to 1, it disables the Quad Pixel selection.
However when I change the number of lanes back to 4, the Quad Pixel selection remains grayed out (It cannot be selected).
What is the reason for this and how can I fix this?
This is a known issue in the Vivado 2015.4 DisplayPort v6.1 (Rev. 1) UI.
This issue is resolved in Vivado 2016.1.
Please see (Xilinx Answer 66301) for a patch for the DisplayPort v6.1 (Rev. 1) in Vivado 2015.4.