[Nouveau] Blank screen at startup (conflict with VESA VGA)

[Pekka Paalanen]

On Mon, 05 Apr 2010 22:59:40 +0200
Didier Spaier <didier.spaier at epsm.fr> wrote:

> I have a Lenovo Thinkpad T61. lspci|grep VGA says:
> 01:00.0 VGA compatible controller: nVidia Corporation Quadro NVS
> 140M (rev a1)
> 
> I have Slacware64-13.0 and Slackware64-current installed.
> 
> Nouveau is modularized in all my kernels for -current.
> 
> A problem arise even if I don't want to use nouveau under X:
> unless nouveau be blacklisted in /etc/modprobe.d/blacklist.conf
> at startup,
> - when using one of the VESA modes at startup after a while
> screen goes blank and I get a warning in syslog e.g: Apr  2
> 18:58:56 darkstar kernel: fb: conflicting fb hw usage nouveaufb
> vs VESA VGA - removing generic driver,

This message is the expected behaviour. It is not an error.
It means the vesafb hand-over is working, or at least it
is attempted.

At what stage does the screen go blank? At X startup?

> - no problem when using a VGA mode (text only),
> 
> this disregarding which X driver I use afterwards (I always start
> in console mode).

Are you trying to use nouveau.ko in kernel, and a non-Nouveau
X driver at the same time? That cannot work.

If nouveau.ko is loaded, the only option for X is to use
the nouveau driver (or perhaps fbdev). Any other driver,
e.g. "vesa" or "nv", will lead to trouble.

What kind of setup are you trying to run in this regard?

> But according to this page:
> http://nouveau.freedesktop.org/wiki/KernelModeSetting
> I thought nouveaufb shouldn't conflict with vesafb ? Am I wrong ?

The hand-over should work: when nouveaufb initialises, vesafb
gets automatically deactivated.

In any case, complete kernel and X logs will help to diagnose
your situation.

-- 
Pekka Paalanen
http://www.iki.fi/pq/