[arch-general] Xorg install problems - solved but some questions

[Fons Adriaensen]

Hello all,

Today I turned my 10th machine into an ArchLinux system.
A Fujitsu W270, nice laptop, just whished it were mine.
Things become routine, I just anticipated some hickups
as this was the first install using the new 'halogen free'
Xorg. That expectation turned out to be true, but ATM
everything works nicely and I just remain with some things
I don't understand.

This machine has Nvidia graphics (Quadro FX 770M) and a
screen resolution of 1680x1050.

I started with a sytem working perfectly in RL 3, with 
nouveau doing an early KMS. Installed xorg, xdm and its
Arch theme, windowmaker and some fonts. 

The first 'init 5' resulted in some fireworks on the screen,
followed by static garbage and a machine that seemed to be
locked up, the only escape being the power button. No panic,
been there before.

Before looking into this I decided to add 'nomodeset' to
my kernel options, just to save my eyes which don't get
younger. Just doing this changed things: on the next 
'init 5' X started and since I had an ~/.xsession ready
I could even log in. But the screen resolution didn't
look OK, it was just 1280x720.

Looking at the logs it turned out that X was using the
vesa driver. It has the 1680x1050 mode natively, but
refused to use it because some sync parameters were out
of range. So it reverted to 1280x720.

Adding a file in /etc/X11/xorg.conf.d defining Monitor,
Device, Screen and the required mode didn't help. 

At that point I was sort of lost. In a desparate attempt
I did a pacman -S xf86-video-nv, and rebooted.

Result: everything OK - X starts with the correct screen
resolution and everything works fine.

So this leaves me with the following question:

Why was X using vesa, and is using nv after I installed
it ? What stops it using nouveau which is already loaded ?
Or does 'nomodeset' stop X using nouveau (things look like
it does, but that is unexpected). 

Another unrelated question: looking at the screeen of this
laptop I suspect it requires a non-standard gamma value.
How can this be set ? 

TIA,


-- 
FA

There are three of them, and Alleline.