Comment # 15 on bug 107978 from freedesktop@sibrenvasse.nl

I own a DELL U2414H and a U2913WM, and are daisy chained via DisplayPort. I'm
currently running into this issue.

A quick bisect gave this result:
 # first bad commit: [0d99889109892396a8164bf6dd178e36d3fe3166] drm/fb-helper:
Eliminate the .best_encoder() usage