On Thu, Nov 01, 2007 at 09:22:22AM +0100, Pierre Ossman wrote:
Hi,
It seems that Lenovo doesn't really believe in the concept of truth in marketing. The panel advertised as 24-bit is actually 18-bit (they claim 16.7 M colors, not 16.2 M or the actual 262 k). To compensate, there is some dithering involved, and seems to give an effect most people describe as "sparkling".
Could it be that it really is a 24bit panel and that, since we do not know any better, we set it up as an 18bit panel and it still works? When i'm back in the office; i should probably try to set up the hp laptop as 24bits. This laptop is a mobility r5xx, 1680x1050, so i was initially quite surprised to see that it was only an 18bit panel. Iirc, i attempted to drive it differently, without success, but this was in the hectic days right before XDS.
This grainy, or sparkly, appearance is a bit annoying and might be the reason why I perceive this display as straining. So I'd like to disable it and see if that makes me a happy camper.
I've been fiddling with the register LVTMA_BIT_DEPTH_CONTROL, disabling the relevant dither bits there. That does indeed remove so much of the dithering that you can start seeing the banding caused by the 18-bit truncation. Unfortunately, the display is still grainy, so something is still active.
Please describe what you mean by grainy? Could there be something else going on besides dithering? I hope it is not something as straightforward as adjusting gamma.
So my question is if there are more things I can tweak or if the remaining issue is just a property of the matrix. TMDSA_BIT_DEPTH_CONTROL seems to be just for TMDS (which is just for DVI?), but there's also a DVOA_BIT_DEPTH_CONTROL which I'm unsure where it fits in.
These are both for seperate outputs and will not influence your panel. Luc Verhaegen. SUSE/Novell X Driver Developer. -- To unsubscribe, e-mail: radeonhd+unsubscribe@opensuse.org For additional commands, e-mail: radeonhd+help@opensuse.org