LCD picture quality 2.6.27 vs 2.6.33

[Peter Clifton]

On Sun, 2010-05-16 at 14:07 -0700, SD wrote:
> Dear All.
> 
> During many month I was trying to figure out what is wrong with picture on my Fedora 13.
> I have laptop with i915GM video and two OS on it - OpenSuse 11.1 and Fedora 13.
> Suse shows picture perfect, but Fedora does not.
> I use XFCE on both OS. Both OS is updated.
> I took digital picture of my screen, and would like you all to analyze it.
> Left side Fedora, right side is OpenSuse.
> Both OS has: "Subpixel:   horizontal rgb", according to "xrandr --verbose"

If you have a good and a bad OS, one useful comparison might be to
gather the output from this command on both:

sudo intel_reg_dumper

You may need intel_gpu_tools installed for this.


Hazarding a guess (and sorry, that is about all I can do to help you),
is that the panel timings "might" be being detected incorrectly on
Fedora. The programming differences should show up in the register
dumps.

I've no idea what different kernel versions / patches / 2D driver
versions are used in the distro versions mentioned.

Make sure you're testing with compiz / visual effects disabled, to rule
out a 3D issue - but from the looks of the picture, I'm sceptical that
is the problem.

Regards,

-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)
Tel: +44 (0)1223 748328 - (Shared lab phone, ask for me)