virtual screen > 2048 pixels, Intel 945

[Jin, Gordon]

Tamas Papp wrote on Tuesday, July 28, 2009 11:21 PM:
> Hi,
> 
> I have an Intel 945 video card in my laptop.  I would like to use an
> external monitor (positioned right of the main screen), but the total
> width exceeds 2048, the virtual screen size, pixels so I can't.  
> 
> My xorg.conf has
> 
> Section "Screen"
>         Identifier "Screen"
>         Device     "Card0"
>         Monitor    "Monitor0"
>         SubSection "Display"
>                Viewport   0 0
>                 Depth     24
>                 Virtual 2560 1024
>         EndSubSection
> EndSection
> 
> so the virtual screen should be big enough, but apparently X ignores
> this.  I found this in the log: 
> 
> (EE) intel(0): Cannot support DRI with frame buffer width > 2048
> 
> Questions:
> 
> 1. Is X ignoring the Virtual setting because of the DRI, or some
> other reason? 
> 2. If it is the DRI, can I disable it somehow?  I tried various
> things (including disabling glx, dri and dri2 in the modules section,
> Option "DRI" "false" for the device), but  
> 
> $ glxinfo | head
> name of display: :0.0
> display: :0  screen: 0
> direct rendering: Yes
> server glx vendor string: SGI
> server glx version string: 1.2
> server glx extensions:
>     GLX_ARB_multisample, GLX_EXT_visual_info, GLX_EXT_visual_rating,
>     GLX_EXT_import_context, GLX_EXT_texture_from_pixmap,
>     GLX_OML_swap_method, GLX_SGI_make_current_read,
>     GLX_SGIS_multisample, GLX_SGIX_hyperpipe, GLX_SGIX_swap_barrier,
> GLX_SGIX_fbconfig, GLX_MESA_copy_sub_buffer 
> 
> and
> 
> $ grep dri /var/log/Xorg.0.log
>         X.Org XInput driver : 4.0
> (WW) "dri" will not be loaded unless you've specified it to be loaded
> elsewhere. (WW) "dri2" will not be loaded unless you've specified it
> to be loaded elsewhere. (II) "dri" will be loaded even though the
> default is to disable it. (II) "dri2" will be loaded even though the
> default is to disable it. 
> 
> so I don't think I was successful.
> 
> Any help would be appreciated.  I am happy to run the laptop without
> DRI, but I need that second screen on the right, not below.  It used
> to work fine, but a recent upgrade (I don't know which) changed
> things.  I am using Debian, $ dpkg -l xserver-xorg-video-intel | grep
> ii   
> ii  xserver-xorg-video-intel                      2:2.8.0-1
> $ uname -r
> 2.6.31-rc4-686
> 
> Thank you,
> 
> Tamas

A kernel fix is required: https://bugs.freedesktop.org/show_bug.cgi?id=21190#c11
It's in drm-intel-next. I don't know if it's in Linus's tree.

Gordon