Debugging dual LVDS display panel color issue

Question

I'm on TI's AM5708 platform (custom board) trying to drive this Full HD panel via TI's DS90C387 Dual-Pixel Display Interface.

The SoC outputs 24bit RGB into DS90C387. And then DS90C387 outputs 8 pairs of LVDS signal into the display panel.

Mostly it's working - I can read the console which is good progress. However, whenever colored data is shown, the display adds extra noise.

For example, here is an image I want to display:

When I tried to show it on the panel using the fbi tool, it shows this:

[update] I notice any color that uses green has issues:

Any pointers will be much appreciated.

Check LVDS pairs being connected to correct pins with correct polarity and whether there is correct bits mapped to correct LVDS lanes. There are two standards how to map the bits to links and that both SoC and panel are using the same link/bit mappings. — Justme, Jan 16, 2019 at 22:39
Thanks. Looking at the photos again, I see that any color that uses green has an issue. Red and blue (and the combinations of) are fine. — Adam Lee, Jan 17, 2019 at 14:23
There indeed was a mismatch in the RGB bit order between the display and the LVDS driver. — Adam Lee, Jan 30, 2019 at 16:17
So here is the exact bit order Driver: 7654_3210 Panel: 5432_1076 I will check on the standard. — Adam Lee, Jan 30, 2019 at 19:34

Justme · Accepted Answer · 2019-01-30 16:58:47Z

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It looks like RGB bits are not correctly mapped to correct lanes as there are at least two standards how to map them (JEIDA and VESA).

answered Jan 30, 2019 at 16:58

Justme

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