KodeMunkie’s SM750 HDMI DRM driver is from today. The tested board is an SE-DP750A-HDMI: SM750G10-AC revision A1, PCI ID 126f:0750, a SiI9024ACNU on GPIO12/13, 16 MiB display memory, one HDMI output. The README says the PCI ID alone is not enough. Other SM750 cards can share 126f:0750 and still be VGA, a different transmitter, or different GPIO.

PANEL_PLANE_BR_RIGHT_MASK is 0x7ff, eleven bits. SM750_DRM_PHYSICAL_MAX_WIDTH is 2048; SM750_DRM_MAX_WIDTH is 2560. 2464x1080 and 2560x1080 are software workspaces compressed to a 2048x1080 HDMI signal. They fill a 2560x1080 panel only if the monitor stretches that signal; otherwise the picture stays 2048 wide or grows borders. A listed catalogue mode is not an EDID restriction. Modes.md puts 70, 72, and 75 Hz at 2048x1080 at 166.239, 171.142, and 178.592 MHz, above the 165 MHz ceiling in Linux’s upstream SiI902x bridge. The hardware notes say the official SM750 spec is already wrong for one partial-update boundary: a narrow dirty rectangle needs one extra output pixel or the rightmost pixel stays stale. The README says this was vibe-coded, physically tested, and is not a claim of upstream kernel quality. I did not run the card.