[Bisect][MST] MST breaks on 5.6

MST works fine on 5.5 but not on 5.6. I bisected it and this commit appears to be the culprit: cd82d82cbc0484e47918d3166f356c98f0066db8 drm/dp_mst: Add branch bandwidth validation to MST atomic check. Specifically I have 3x1080p60 monitors daisy chained together and usually only 2, very rarely only 1 will actually come on. The 3rd is detected and listed in swaymsg -t get_outputs as inactivate but I can't get it to activate. The card is an RX 5700 XT.