[CentOS] App not finding /dev/nvidia0 for /dev/dri/card0 not found on inspiron 8200 with nvidia chipset

Bryan J. Smith thebs413 at earthlink.net
Tue Nov 8 16:25:27 UTC 2005

On 11/7/05, Jerry Geis <geisj at pagestation.com> wrote:
> I have source for a program that is attempting to open
> /dev/nvidia0 then on failure open /dev/dri/card0
> to get some vsync settings.

You _must_disable_ DRI if you load the nVidia driver!

nVidia does _not_ use the Direct Rendering Infrastructure
(DRI) for OpenGL, it provides a full OpenGL over X11 (GLX)

[ Think of DRI v. GLX as the old "Mini Client Driver" (MCD)
v. the full "Installable Client Driver" (ICD) support for
OpenGL in the Windows world.  Having a full GLX
implementation is better, long story. ]

Comment out the line
  Module "DRI"
near the top of your XF86config/Xorg configuration file.  The
DRI section at the end will be ignored (don't worry about
commenting it out).

> Neither of those two files is found on my laptop in /dev.
> Is this because of udev?

On FC3+/RHEL4+, yes.  There are many "proper" ways to set
this up.  This is the easiest way although not the most
"proper" (just copy the dev files to /etc/udev/devices/) ...
  1.  Re-install the nVidia driver (creates /dev/ entries)
  2.  Run:  
      cp -a /dev/nvidia* /etc/udev/devices
      chown root.root /etc/udev/devices/nvidia*

Jim Perrin <jperrin at gmail.com> wrote:
> No, /dev/nvidia0 exists on my centos 4.2 box in /dev
> You should check that you have nvidia's drivers installed
> correctly and that the nvidia module is loaded by checking
> with lsmod.

udev is the culprit.

> I think xdpyinfo gives you this. I can't remember.


But open your monitor's manual and get the maximum specs for
your monitor and set them in the XF86Config/Xorg file first.

Bryan J. Smith                | Sent from Yahoo Mail
mailto:b.j.smith at ieee.org     |  (please excuse any
http://thebs413.blogspot.com/ |   missing headers)

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