[kde-linux] debian wheezy : kde nvidia - nouveau

[Duncan]

Peter Catchlove posted on Fri, 03 Aug 2012 11:15:36 +0200 as excerpted:

> Dear KDE'ers
> 
> I've been using debian -testing with kde for over 10 years, and although
> not terribly pc-competent, it's worked pretty well. But it's getting
> more-and-more difficult.
> 
> The latest upgrades have left me with what looks like a graphics
> problem: I have an nvidia card, and a while ago on an upgrade I had with
> great difficulty to move to the nouveau graphics driver. Since more
> recent upgrades, iceweasel now shows funny artefacts affecting the text,
> but when you define a block or move the area off-screen and back again,
> they disappear.
> Is that a graphics problem?
> Occasionally I have seen the same behaviour with other applications.
> 
> Right now it's with xsane: the preview window is so graphically
> challenged, it makes the app unusable.
> Makes me wonder if this is a problem with gtk applications generally.
> 
> If anyone can offer a word of advice or comfort, many thanks in advance.

FWIW I won't run nvidia hardware here due to their lack of cooperation 
with the freedomware community, so I'm running amd/radeon, and I run 
gentoo, so don't know much about debian.

But yes, font rendering artifacts that disappear on forced repaint as you 
describe are graphics driver related.

What I'd suggest as a simple test, is to disable desktop effects 
temporarily, and see if that changes the problem.  You can also try 
switching between opengl and xrender as the effects backend.  xrender 
will likely be slower and won't handle some effects, but may well 
eliminate the problem.  If turning off effects does eliminate it, you've 
confirmed the problem as effects related.  If switching to xrender does 
as well, then it's almost certainly opengl related.

Desktop effects can be found in kde settings under workspace appearance 
and behavior.

You may be able to toggle various nouveau driver options to help with the 
problem too, but I haven't a clue on that hardware and driver, so I'll 
leave that bit to someone else.  But knowing whether toggling effects and/
or opengl/xrender effects mode helps should go a long way, regardless.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman