Problem with custom simple panel display. I've created my compatible display structure, following the existing codes. In the struct drm_display_mode, i need to set DE polarity, but when i add to code .flags = DRM_MODE_FLAG_NDE, mode is not created

[Lmoio.1]

When I don't use the .flags, i see the mode created, but my display doesn't work. I changed the ltdc register (GCR) manually to set DE and it works. When i add the .flags, no mode is created (i checked with modetest -M stm). Since i understood that this is part of a ST patch, can you please check the behaviour?

Thanks