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

[Didier Spaier]

Thanks for your answer.

I tried with a 2.6.32.2 kernel (nouveau works under X).

Pekka Paalanen wrote:
> 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?

Nope. I start the system in console mode and get the blank screen before bash prompt, when it tries to switch from VESA to nouveaufb.

> 
>> - 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?
> 
I know that using another X driver than nouveau whilst nouveau kernel module is loaded shouldn't and doesn't work, I've tried that a couple of times ;)

But here the screen, goes blank *before* i can even type "startx" if I start if VESA mode.

Iff I can see the screen on the console I have no problem to use nouveau under X

Whenever I start Linux with lilo, having lilo option "VGA=ask" in lilo.conf:
-> If I choose a VESA mode I get a blank screen at time of (automatically) switching to nouveaufb before bash prompt.
-> If I choose a VGA mode switching occurs with no problem ("old" screen in 80x25 is erased but I can see the new messages in 1680x1050).

>> 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.
> 
Yes but it seems than if vesafb was loaded nouveaufb doesn't work well at first

> In any case, complete kernel and X logs will help to diagnose
> your situation.
> 
Logs are appended (only kernel logs, not X logs as I have no problem to use nouveau under X provided I can see the screen to type "startx" ;)
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