This can be caused by a variety of problems, such as PCI IRQ routing errors, I/O APIC problems or conflicts with other devices sharing the IRQ (or their drivers).

If possible, configure your system such that your graphics card does not share its IRQ with other devices (try moving the graphics card to another slot if applicable, unload/disable the driver(s) for the device(s) sharing the card's IRQ, or remove/disable the device(s)).

An edge-triggered interrupt means that the kernel has programmed the interrupt as edge-triggered rather than level-triggered in the Advanced Programmable Interrupt Controller (APIC). Edge-triggered interrupts are not intended to be used for sharing an interrupt line between multiple devices; level-triggered interrupts are the intended trigger for such usage. When using edge-triggered interrupts, it is common for device drivers using that interrupt line to stop receiving interrupts. This would appear to the end user as those devices no longer working, and potentially as a full system hang. These problems tend to be more common when multiple devices are sharing that interrupt line.

If X starts but you have trouble with OpenGL, you most likely have a problem with other libraries in the way, or there are stale symlinks. See Chapter 4, Installed Components for details.

You should also check that the correct extensions are present;

    % xdpyinfo

should show the “GLX” and “NV-GLX” extensions present. If these two extensions are not present, then there is most likely a problem loading the glx module, or it is unable to implicitly load GLcore. Check your X config file and make sure that you are loading glx (see Chapter 6, Configuring X for the NVIDIA Driver). If your X config file is correct, then check the X log file for warnings/errors pertaining to GLX. Also check that all of the necessary symlinks are in place (refer to Chapter 4, Installed Components).

This problem occurs with DDC and "blue line" stereo glasses, that get the stereo signal from one video port of the graphics card. When a X screen does not display any stereo drawable the stereo signal is disabled on the associated video port.

Forcing stereo flipping allows the stereo glasses to shutter continuously. This can be done by enabling the OpenGL control "Force Stereo Flipping" in nvidia-settings, or by setting the X configuration option "ForceStereoFlipping" to "1".

There are two cases where this may occur. If the displays are attached to the same GPU, and one of them is out of sync with the stereo glasses, you will need to reconfigure your monitors to drive identical mode timings; see Chapter 18, Programming Modes for details.

If the displays are attached to different GPUs, the only way to synchronize stereo across the displays is with a G-Sync device, which is only supported by certain Quadro cards. See Chapter 25, Configuring Frame Lock and Genlock for details. This applies to seperate GPUs on seperate cards as well as seperate GPUs on the same card, such as Quadro FX 4500 X2. Note that the Quadro FX 4500 X2 only provides a single DIN connector for stereo, tied to the bottommost GPU. In order to synchronize onboard stereo on the other GPU you must use a G-Sync device.

The system BIOS has not properly set up your graphics card; FreeBSD can't currently set up PCI devices that the BIOS leaves unconfigured. Uncheck "PNP-OS" in your system BIOS.

On certain FreeBSD kernels, it may be necessary to add the following line to /boot/loader.conf:

hw.pci.allow_unsupported_io_range="1"

This should allow the NVIDIA kernel module to attach.

The NVIDIA driver may require more IPC resources than are allocated by default. If this happens, you may be able to work around this problem by increasing your system's resource limits by editing the file /boot/loader.conf and adding:

kern.ipc.shmseg=1024
kern.ipc.shmmni=1024

The values above were chosen conservatively, you may need to tweak them to meet your requirements.

Nothing will work if the NVIDIA kernel module does not function properly. If you see anything in the X log file like

(EE) NVIDIA(0): Failed to initialize the NVIDIA kernel module!

then there is most likely a problem with the NVIDIA kernel module.

The NVIDIA kernel module may print error messages indicating a problem -- to view these messages check the output of dmesg, /var/log/messages, or wherever syslog is directed to place kernel messages. These messages are prepended with "NVRM".

Due to differences between the gtk+-2.x ports packages included with different FreeBSD releases, the prebuilt nvidia-settings binary shipped with the NVIDIA driver may not work with FreeBSD releases more recent than FreeBSD 7.3.

If you have a recent ports package of gtk+-2.x and gmake installed on your system, you can build the nvidia-installer utility from source to solve this problem.

Download nvidia-settings-256.52.tar.bz2 from ftp://download.nvidia.com/XFree86/nvidia-settings You can then extract, build and install it (to /usr/local/bin) with:

    % gmake install

Depending on the shell you are using, you may need to force it to recompute its internal table of executable files present in the directories listed in the $PATH variable. Assuming you are using the FreeBSD default shell you can do so by issuing the command:

    % rehash

When initialized by an application executed with 'root' privileges, the NVIDIA Linux OpenGL library, shipped with the NVIDIA FreeBSD graphics driver for Linux ABI compatibility, will attempt to load the NVIDIA Linux kernel module and fail because /sbin/modprobe is absent. You can work around this problem by creating a symbolic link from /usr/bin/true to /compat/linux/sbin/modprobe:

    % ln -s /usr/bin/true /compat/linux/sbin/modprobe

If you're using an AGP card, your stability problems may be AGP-related. See Chapter 11, Configuring AGP for details.

The application is probably using a different library that still remains on your system, rather than the NVIDIA supplied OpenGL library. See Chapter 4, Installed Components for details.

Quake2 requires some minor setup to get it going. First, in the Quake2 directory, the install creates a symlink called libGL.so that points at libMesaGL.so. This symlink should be removed or renamed. Second, in order to run Quake2 in OpenGL mode, you must type

    % quake2 +set vid_ref glx +set gl_driver libGL.so

Quake2 does not seem to support any kind of full-screen mode, but you can run your X server at the same resolution as Quake2 to emulate full-screen mode.

Most of the X startup delay problems we have found are caused by incorrect data in video BIOSes about what display devices are possibly connected or what i2c port should be used for detection. You can work around these problems with the X config option IgnoreDisplayDevices (see the description in Appendix B, X Config Options).

Incorrectly sized fonts are generally caused by incorrect DPI (Dots Per Inch) information. You can check what X thinks the physical size of your monitor is, by running:

 % xdpyinfo | grep dimensions

This will report the size in pixels, and in millimeters.

If these numbers are wrong, you can correct them by modifying the X server's DPI setting. See Appendix E, Dots Per Inch for details.

There are some known timing and signal integrity issues on ALi chipsets. The following tips may help stabilize problematic ALI systems:

The installation of GNOME provided in operating systems such as FreeBSD 7 contain several competing interfaces for specifying resolution:

    'System Settings' -> 'Display'

which will update the X configuration file, and

    'Applications' -> 'Preferences' -> 'Screen Resolution'

which will update the per-user screen resolution using the XRandR extension. Your desktop resolution will be limited to the smaller of the two settings. Be sure to check the setting of each.

The NVIDIA X driver uses the X Int10 module to save and restore console state on TV out, and will not be able to restore the console correctly if it cannot use the Int10 module. If you have built the X server yourself, please be sure you have built the Int10 module. If you are using a build of the X server provided by your operating system and are missing the Int10 module, contact your operating system distributor.

The NVIDIA OpenGL driver must be able to map the /dev/zero device node with read, write, and execute privileges in order to function correctly. The driver needs this ability to allocate executable memory, which is used for optimizations that require generating code at run-time. Currently, GLX cannot run without these optimizations.

Check that your /dev filesystem is set up correctly. In particular, mounting the /dev file system with the 'noexec' option will cause this to happen. If you haven't changed the configuration of your /dev filesystem, please contact your operating system distributor.

The NVIDIA X driver needs to be able to access the buffers it allocates from the CPU, but wasn't able to set up this access. This commonly fails if you're using a large virtual desktop size. Although your GPU may have enough onboard video memory for the buffer, the amount of usable memory may be limited if the IndirectMemoryAccess option is disabled, or if not enough address space was reserved for indirect memory access (this commonly occurs on 32-bit systems). If you're seeing this problem and are using a 32-bit operating system, it may be resolved by switching to a 64-bit operating system.