Re: Enabling a second graphic card

[berenger.morel@neutralite.org]

Le 01.10.2014 17:26, Sven Joachim a écrit :
> On 2014-10-01 16:39 +0200, berenger.morel@neutralite.org wrote:
>
> > I have recently acquired 2 (identical, 4/3 shaped) screens, so I
> > combined them with my current favorite screen on a computer which 
> > have
> > 2 graphic cards, but it seems that Debian did not enabled the second
> > card.
> >
> > I have tried it on a temporary Ubuntu install, and it works fine out
> > of the box, so Debian must be able to use that 2nd card too. I tried
> > to install a more recent kernel from backports on Debian just in 
> > case,
> > but still no luck. Now that I'm thinking about it, I did not checked
> > what Ubuntu uses as driver, so if it uses NVidia, this could be the
> > reason, since I'm using nouveau on Debian. But I think that Ubuntu
> > does not install proprietary blobs by default?
> > I tried to find a xorg.conf in /etc on both system, no one had it.
> >
> > There is no Internet access from that computer, so packages are
> > installed from the Ubuntu DVD I bought 2-3 months ago (14.04 IIRC) 
> > and
> > from a Debian DVD set I have downloaded at work (7.5, DVDs 1 to 9
> > IIRC).
>
> Obviously, Ubuntu 14.04 is quite a bit newer than Debian 7, so some
> things which work there might not be supported in Wheezy.

Indeed, that's why I tried backported kernel (which is newer than 
Ubuntu's one)...

> > Does anyone knows if nouveau is supports a configuration with 2
> > graphic cards, or do I have to install NVidia's drivers to do the 
> > job?
> > Does someone have some links to documents which could explain how to
> > enable that 2nd card?
>
> http://nouveau.freedesktop.org/wiki/MultiMonitorDesktop/ has some
> information.

Yes, it seems that there is a configuration file to create, in order to 
handle multiple cards. And it have to use xinerama.
I'll try it ASAP, and hopefully I'll be able to adapt it to the disk 
I'm making (I'm trying to configure a system to be able to run on 
various computers, since it is installed on an external USB harddisk. If 
if's a matter of enabling/disabling a configuration file at boot, that 
won't be hard.).

> > Note that I think the second card is disabled, because after doing
> > quick searches in /sys, I discovered that what I suppose to be the
> > second card directory have a file named "enabled" which contains
> > "0". But I'm not expert at all when it comes to kernel stuff.
>
> Me neither, but running "dmesg | grep nouveau" could be useful.
>
> Cheers,
>        Sven