Problem with dual screens #366
Description
Opencore 1.0.5 used with latests .kext on H310M Sp2 V2 motherboard. Monitor 1: Samsung S24C350 1920x1080 connected to Hdmi, detected at framebuffer 2, Monitor 2: IISonic 1280*1024 connected to VGA and detected at frambuffer 0.
Each monitor connected individually: everything goes well. Hotplugging monitors both works too.
The problem: cold start. The phase with the progress bar displays correctly, then displays correctly on the VGA and when the HDMI monitor wants to display the desktop I have flickering with horizontal black bars on both monitors.
I don't know how to debug this, I have try to force Port types like written here : https://github.com/dortania/OpenCore-Post-Install/blob/master/gpu-patching/intel-patching/connector.md without succes.
With -igfxdump I get only at end : 2025-07-31 10:08:23.758076+0200 0x918 Default 0x0 0 0 kernel: (AppleIntelCFLGraphicsFramebuffer) [IGFB][LOG ][PLANE ] [Flip_Transaction] Pipe Gamma Enable
2025-07-31 10:08:24.027975+0200 0x929 Default 0x0 0 0 kernel: (AppleIntelCFLGraphicsFramebuffer) [IGFB][LOG ][TRANSACTION] [Flip_Transaction] FB2: Flipping display with wsaa 1 flipped from 1920 x 1080 -> 1920 x 1080 on 45fb9000 with 1 options at stride 7680
2025-07-31 10:29:34.862951+0200 0x918 Default 0x0 0 0 kernel: (AppleIntelCFLGraphicsFramebuffer) [IGFB][LOG ][TRANSACTION] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 1280 x 1024 -> 1280 x 1024 on 448d0000 with 1 options at stride 5120
My AAPL,ig-platform-id is detected as <07 00 9b 3e> device-id <91 3e 00 00> .
iMac19,1 emulated , Coffe Lake i3-9100 Cpu Uhd630, desktop.
Same problem under Monterey, Ventura, Sonoma, but no problem with Linux or Windows on same machine
How to debug more ?