Created attachment 141223 [details]
X log, three-monitor setup, DP port in HDMI mode (works)
When two external monitors supporting the same timings are connected, the driver attempts to reuse a CRTC, however this fails if one is connected via DP and the other via HDMI or DVI, as the DP link requires a different PLL setup.
xrandr handles this restriction, reporting an error from the CRTC setup (the virtual CRTC 2 just reports failure), but on startup, this check is not performed properly, and the X server starts up with two usable displays and one confused monitor that will neither go to powersave nor show a picture.
Created attachment 141224 [details]
X log, three-monitor setup, DP port in DP mode (fails)
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