Hi Maxime,

Maxime Ripard wrote:

The current code always registers as a 32 bits display, and uses the
hardware to drop the MSB of each color to abjust to the interface width
used by the panel.

This results on 18 bits (and probably 16 bits display as well) in colors
being displayed poorly, because the MSB are obviously the most important
bits for each color definition.

But the "def_rgb666" bitfield description reports correctly to use bit 0..5 
for each colour component in this mode. Maybe your userland program has a bug 
and forgets to honor the bitfield description?

The default controller behaviour when using an interface width smaller
than the color depth is to drop the LSBs of each color, which makes more
sense because you lose the least important part of the color definition.

So, to fix the colors display, just get back to the default controller
behaviour.

If you do this change, you also must adapt the "def_rgb666" bitfield 
description.
This structure currently reports the lower 6 bits to be used for this mode:
  blue -> 0..5 (skip 6/7)
  green -> 8..13 (skip 14/15)
  red -> 16..21 (skip 22/23).

[...]

jbe

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