okay habe es anders gemacht, über edid-decode die edid aus
/sys/class/drm/card0-HDMI-A-1/device/card0-HDMI-A-1 ausgelesen.
Da sind folgende Modelines definiert:
VIC 16 1920x1080@60Hz 16:9 HorFreq: 67500 Hz Clock: 148.500 MHz
VIC 31 1920x1080@50Hz 16:9 HorFreq: 56250 Hz Clock: 148.500 MHz
VIC 5 1920x1080i@60Hz 16:9 HorFreq: 33750 Hz Clock: 74.250 MHz
VIC 20 1920x1080i@50Hz 16:9 HorFreq: 28125 Hz Clock: 74.250 MHz
VIC 32 1920x1080@24Hz 16:9 HorFreq: 27000 Hz Clock: 74.250 MHz
VIC 33 1920x1080@25Hz 16:9 HorFreq: 28125 Hz Clock: 74.250 MHz
VIC 34 1920x1080@30Hz 16:9 HorFreq: 33750 Hz Clock: 74.250 MHz
VIC 4 1280x720@60Hz 16:9 HorFreq: 45000 Hz Clock: 74.250 MHz
VIC 19 1280x720@50Hz 16:9 HorFreq: 37500 Hz Clock: 74.250 MHz
VIC 3 720x480@60Hz 16:9 HorFreq: 31469 Hz Clock: 27.000 MHz
VIC 18 720x576@50Hz 16:9 HorFreq: 31250 Hz Clock: 27.000 MHz
VIC 7 1440x480i@60Hz 16:9 HorFreq: 15734 Hz Clock: 27.000 MHz
VIC 22 1440x576i@50Hz 16:9 HorFreq: 15625 Hz Clock: 27.000 MHz
VIC 93 3840x2160@24Hz 16:9 HorFreq: 54000 Hz Clock: 297.000 MHz
VIC 94 3840x2160@25Hz 16:9 HorFreq: 56250 Hz Clock: 297.000 MHz
VIC 95 3840x2160@30Hz 16:9 HorFreq: 67500 Hz Clock: 297.000 MHz
VIC 98 4096x2160@24Hz 256:135 HorFreq: 54000 Hz Clock: 297.000 MHz
VIC 99 4096x2160@25Hz 256:135 HorFreq: 56250 Hz Clock: 297.000 MHz
VIC 100 4096x2160@30Hz 256:135 HorFreq: 67500 Hz Clock: 297.000 MHz
VIC 97 3840x2160@60Hz 16:9 HorFreq: 135000 Hz Clock: 594.000 MHz
VIC 96 3840x2160@50Hz 16:9 HorFreq: 112500 Hz Clock: 594.000 MHz
VIC 102 4096x2160@60Hz 256:135 HorFreq: 135000 Hz Clock: 594.000 MHz
VIC 101 4096x2160@50Hz 256:135 HorFreq: 112500 Hz Clock: 594.000 MHz
Also auch 50Hz wäre dabei..