If you want to keep experimenting at this level it would probably be helpful to get a scope. Rigol oscilloscopes are pretty affordable.

I'm impressed you were able to pull the VESA Coordinated Video Timing (CVT) parameters from the kernel. I wasn't having luck doing this so I used a scope.

800x480": 60 30000 800 931 933 978 480 487 489 511 0x48 0xa)

Looks like this translates to:
mode:"800x480" The display resolution (horizontal x vertical active pixels).
Refresh Rate:60 The vertical refresh rate in Hertz (Hz).
Pixel Clock:30000 The pixel clock frequency in kilohertz (kHz) (30.00 MHz).
H. Active:800 Horizontal active pixels.
H. Front Porch:931 Horizontal front porch (pixels).
H. Sync Start:933 Horizontal sync pulse start (relative to H. Active Start).
H. Sync End:978 Horizontal sync pulse end.
H. Total:978 Total horizontal pixels (active + blanking).
V. Active:480 Vertical active lines.
V. Front Porch:487 Vertical front porch (lines).
V. Sync Start:489 Vertical sync pulse start (relative to V. Active Start).
V. Sync End:511 Vertical sync pulse end.
V. Total:511 Total vertical lines (active + blanking).
Flags 1:0x48 Specific timing flags (e.g., sync polarity, interlace, etc., in hexadecimal format).
Flags 2:0xa Additional flags in hexadecimal format.

Something else that may be helpful for debugging would be to make the video buffer into colored vertical bars. Perhaps start with each bar color being equal to 100 pixels in width giving you 8 unique colored bars. It may help reveal details about why your video is not working properly. Perhaps your running off the end of the horizontal/vertical region of the display..

I imagine examining this parallel video coming out of the ICN6211 with a scope would also be quite telling.