LCM flicker

[Carsten Haitzler (The Rasterman)]

On Mon, 10 Mar 2008 08:27:23 +0000 Andy Green <andy at openmoko.com> babbled:

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> Somebody in the thread at some point said:
> 
> > one thing it could be is the LSB of all channels is wobbling, and since R &
> > B have 1 less bit - it's much more noticable. green might flicker and we
> > just
> 
> Good idea Carsten -- and in fact the physical interface to the LCM is
> 6:6:6 fittingly enough, and that is what is wired through to the Glamo.
>  But glamo framebuffer in U-Boot anyway (X too?) is 5:6:5 and it is
> *red* and *blue* that lack the LSB.

well 6bits is what the lcd accepts (6:6:6 indeed) and the glamo needs to fill
in the extra 1 bit for R & G (G goes straight through as all 6 bits are used).
that extra 1 bit needs to be interpolated from 0 to 1 as the other 5 bits
increase in value. but flicker ONLY happens when R != B.  and it gets worse the
more difference between R & B. now if those lines are flapping and not grounded
- maybe they are picking up electrical field signals, but if both R & B carry
the same signal the field is nullified and these no carrier is going down bit 6
on these 2 runs? it's a wild guess, but its about the only thing i can think
that may explain it. i'm going to try this "pump up the signal power" thing,
but for all i know it could get worse. :/

now - back to trying to build this kernel...

> - -Andy
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-- 
Carsten Haitzler (The Rasterman) <raster at openmoko.org>