Forcing DisplayPort properties for sink debugging

When performing debugging of the different projector source ports (VGA, DVI, HDMI), we need to exactly control the timing sent by the graphics card and force this even though the sink’s EDID is invalid or missing. This is accomplished with the X Config Options described in Appendix B of the Linux driver’s README.

Now, we want to do the same thing with DisplayPort, and as far as timing goes, this is not a problem, but we would like to force a couple of more options. From the top of my head:

  • Lane count
  • Lane speed (RBR/HBR/HBR2)
  • Pre-emphasis
  • Drive strength
  • AUX channel communication
  • Error injection
  • Inter-lane spread spectrum
  • Intra-lane skew
  • other?

Are any of these possible to accomplish?

You should be able to force the mode timings themselves exactly the same way you are for the other display types. However, there is no mechanism for forcing the DP-specific options you specified.