Dolby Vision for Minix U22X-J (Max) and Ugoos AM6+

[liquidion]

@cpm also did some initial research into this 12-bit bug, the findings are here, hopefully we can get a conversation going:

CE-NG Dolby Vision for G12 boxes (u22xj, am6+, firetv cube)

I am wondering if: force_mode_switch_by_dv maybe the root cause - or another similar check for res etc. which is ultimately causing a call to: drmModeSetCrtc possibly that is causing a HPD event or something else which will trigger the set_display_mode_auto on the amlogic side. If so possibly can front run with a call to hdmitx_set_vsif_pkt Not in a position for a week or so to try this out myself - any thoughts?