DisplayPort Link training optimization

代码说明：

说明：  介绍了Displayport规格中lind training的背景研究，设计和实现。(As the requirement for bandwidth continues to increase in the video market, retaining the signal integrity becomes increasingly more difficult. For many of todays commonly used video interfaces, there are devices that can be used to assist in this matter. However, the use of such a device is only partially documented in the DisplayPort specification for the receiving image device, which means that the receiving side of the video link is free to choose its own implementation. This report presents, together with background research and design decisions, a suggestion for such an implementation. This implementation would need to be compatible towards a wide range of possible video Source devices and DisplayPort cables.)