Nouveau - Apr 2010 - Blank screen at startup (conflict with VESA VGA)

Hi all,

new to this list ;)

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,
- no problem when using a VGA mode (text only),

this disregarding which X driver I use afterwards (I always start in console
mode).

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

I tried with modules shipped in vanilla 2.6.33.1 as well as the last Nouveau
kernel repository pulled from git: no luck in both cases.

I know there are easy workarounds: either use "VGA=ask",
"VGA=ext" or "VGA=normal" as a lilo.conf option or blacklist
nouveau -- which doesn't hurt anyway as nouveau will be loaded at X startup
anyhow.

But this is still is an annoyance for newcomers as when they are trapped all
they can do if they have a VESA mode in lilo.conf is launch another system or
live CD/DVD and either edit lilo.conf and run lilo again or edit blacklist.conf
to blacklist nouveau.

But still, before kindly requesting Patrick Volkerding to blacklist nouveau in
-current for the time being, I wanted to now of another way to go if possible.

Thanks in advance for your answers,

Didier

On Mon, Apr 05, 2010 at 10:59:40PM +0200, Didier Spaier
wrote:
> Hi all,
> 
> new to this list ;)
> 
> 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,
It should work. Please provide full kernel log.
> - no problem when using a VGA mode (text only),
But Nouveau framebuffer activates without errors, right?
> 
> this disregarding which X driver I use afterwards (I always start in
console mode).
> 
> But according to this page:
> http://nouveau.freedesktop.org/wiki/KernelModeSetting
> I thought nouveaufb shouldn't conflict with vesafb ? Am I wrong ?
> 
> I tried with modules shipped in vanilla 2.6.33.1 as well as the last
Nouveau kernel repository pulled from git: no luck in both cases.
> 
> I know there are easy workarounds: either use "VGA=ask",
"VGA=ext" or "VGA=normal" as a lilo.conf option or blacklist
nouveau -- which doesn't hurt anyway as nouveau will be loaded at X startup
anyhow.
> 
> But this is still is an annoyance for newcomers as when they are trapped
all they can do if they have a VESA mode in lilo.conf is launch another system
or live CD/DVD and either edit lilo.conf and run lilo again or edit
blacklist.conf to blacklist nouveau.
> 
> But still, before kindly requesting Patrick Volkerding to blacklist nouveau
in -current for the time being, I wanted to now of another way to go if
possible.
> 
> Thanks in advance for your answers,
> 
> Didier

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/

Ok, let's CC nouveau list back.

On Mon, Apr 12, 2010 at 12:31:58PM +0200, Didier Spaier
wrote:
> >> One thing I didn't check before sending my last mail: can I go
back
> >> to console mode after having started X with say, the nv X module ?
> >>
> >> Unfortunately this doesn't work: be it from Fluxbox or KDE,
when
> >> I logout or use Alt+Ctrl+Fn I see a black screen.
> > 
> > nv or nouveau?
> > running nv (X) with nouveau kernel module is unsupported
> 
> Running nv (X).
> 
> I understand that running nv (X) with nouveau kernel module is unsupported,
> but if a nVidia GPU is detected the nouveau kernel module is automatically
> loaded during startup (unless blacklisted, of course).
> 
> This don't prevent to run X with the nv module (in a distribution in
which
> nouveau (X) is not available, for instance), but going back to console mode
> doen't work in that case.
> 
> Is there any way to make it working, as some distributions do not include
> (yet) all components needed for nouveau (mainly matching libdrm and X
module) ?
I'm not aware of any trick to make both nv and nouveau working.
Maybe there should be a way to prevent nv (and vesa, but not fbdev) from loading
when KMS is in use?
>  > nouveau kernel module works only with nouveau and fbdev X drivers
> 
> I'll will try with fbdev then.


Marcin